Glide使用详解(一)

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         Glide使用详解(一)

标签: GlideGlide使用Glide详解Glide教程
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目录(?)[+]

一. 下载

在build.gradle中添加依赖:

<code class="language-gradle hljs bash has-numbering">    compile <span class="hljs-string">'com.github.bumptech.glide:glide:3.7.0'</span></code><ul class="pre-numbering"><li>1</li></ul>

需要support-v4库的支持,如果你的项目没有support-v4库(项目默认已经添加了),还需要添加support-v4依赖:

<code class="language-gradle hljs bash has-numbering">    compile <span class="hljs-string">'com.android.support:support-v4:23.3.0'</span></code><ul class="pre-numbering"><li>1</li></ul>

然后配置混淆规则:

<code class="hljs java has-numbering">    -keep <span class="hljs-keyword">public</span> <span class="hljs-class"><span class="hljs-keyword">class</span> * <span class="hljs-keyword">implements</span> <span class="hljs-title">com</span>.<span class="hljs-title">bumptech</span>.<span class="hljs-title">glide</span>.<span class="hljs-title">module</span>.<span class="hljs-title">GlideModule</span>    -<span class="hljs-title">keep</span> <span class="hljs-title">public</span> <span class="hljs-title">enum</span> <span class="hljs-title">com</span>.<span class="hljs-title">bumptech</span>.<span class="hljs-title">glide</span>.<span class="hljs-title">load</span>.<span class="hljs-title">resource</span>.<span class="hljs-title">bitmap</span>.<span class="hljs-title">ImageHeaderParser</span>$** {</span>      **[] $VALUES;      <span class="hljs-keyword">public</span> *;    }</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li></ul>

其中第一个混淆规则表明不混淆所有的GlideModule
如果需要的话,还需添加相应的权限:

<code class="language-xml hljs  has-numbering">    <span class="hljs-tag"><<span class="hljs-title">uses-permission</span> <span class="hljs-attribute">android:name</span>=<span class="hljs-value">"android.permission.INTERNET"</span> /></span>    <span class="hljs-tag"><<span class="hljs-title">uses-permission</span> <span class="hljs-attribute">android:name</span>=<span class="hljs-value">"android.permission.WRITE_EXTERNAL_STORAGE"</span> /></span></code><ul class="pre-numbering"><li>1</li><li>2</li></ul>

二. 集成网络框架OkHttp(可选)

Glide的网络请求部分可以使用当前最流行的网络请求框架Volley或OkHttp,也可以通过Glide的ModelLoader接口自己写网络请求。
Glide默认使用HttpUrlConnection进行网络请求,为了让APP保持一致的网络请求形式,可以让Glide使用我们指定的网络请求形式请求网络资源,这里我们选OkHttp (具有支持HTTP/2、利用连接池技术减少请求延迟、缓存响应结果等等优点),需要添加一个集成库:

<code class="language-gradle hljs cs has-numbering">    <span class="hljs-comment">//OkHttp 2.x</span>    <span class="hljs-comment">//compile 'com.github.bumptech.glide:okhttp-integration:1.4.0@aar'</span>    <span class="hljs-comment">//compile 'com.squareup.okhttp:okhttp:2.7.5'</span>    <span class="hljs-comment">//OkHttp 3.x</span>    compile <span class="hljs-string">'com.github.bumptech.glide:okhttp3-integration:1.4.0@aar'</span>    compile <span class="hljs-string">'com.squareup.okhttp3:okhttp:3.2.0'</span></code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li></ul>

注意:
1. OkHttp 2.x和OkHttp 3.x需使用不同的集成库。
2. Gradle会自动将OkHttpGlideModule合并到应用的manifest文件中。
3. 如果你没有对所有的GlideModule配置混淆规则(即没有使用-keep public class * implements com.bumptech.glide.module.GlideModule),则需要把OkHttp的GlideModule进行防混淆配置:

<code class="hljs avrasm has-numbering">-keep class <span class="hljs-keyword">com</span><span class="hljs-preprocessor">.bumptech</span><span class="hljs-preprocessor">.glide</span><span class="hljs-preprocessor">.integration</span><span class="hljs-preprocessor">.okhttp</span><span class="hljs-preprocessor">.OkHttpGlideModule</span></code><ul class="pre-numbering"><li>1</li></ul>

三. 使用

简单使用

<code class="language-java hljs  has-numbering">Glide    .with(<span class="hljs-keyword">this</span>)    .load(<span class="hljs-string">"http://inthecheesefactory.com/uploads/source/nestedfragment/fragments.png"</span>)    .into(imageView);</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li></ul>

Glide.with()使用

  1. with(Context context). 使用Application上下文,Glide请求将不受Activity/Fragment生命周期控制。
  2. with(Activity activity).使用Activity作为上下文,Glide的请求会受到Activity生命周期控制。
  3. with(FragmentActivity activity).Glide的请求会受到FragmentActivity生命周期控制。
  4. with(android.app.Fragment fragment).Glide的请求会受到Fragment 生命周期控制。
  5. with(android.support.v4.app.Fragment fragment).Glide的请求会受到Fragment生命周期控制。

返回关联了相应上下文的RequestManager实例。

requestManager.load()使用

Glide基本可以load任何可以拿到的媒体资源,如:
load SD卡资源:load("file://"+ Environment.getExternalStorageDirectory().getPath()+"/test.jpg")
load assets资源:load("file:///android_asset/f003.gif")
load raw资源:load("android.resource://com.frank.glide/raw/raw_1")或load("android.resource://com.frank.glide/raw/"+R.raw.raw_1)
load drawable资源:load("android.resource://com.frank.glide/drawable/news")或load("android.resource://com.frank.glide/drawable/"+R.drawable.news)
load ContentProvider资源:load("content://media/external/images/media/139469")
load http资源:load("http://img.my.csdn.net/uploads/201508/05/1438760757_3588.jpg")
load https资源:load("https://img.alicdn.com/tps/TB1uyhoMpXXXXcLXVXXXXXXXXXX-476-538.jpg_240x5000q50.jpg_.webp")
当然,load不限于String类型,还可以:
load(Uri uri)load(File file)load(Integer resourceId)load(URL url)load(byte[] model)load(T model)loadFromMediaStore(Uri uri)
load的资源也可以是本地视频,如果想要load网络视频或更高级的操作可以使用VideoView等其它控件完成。
而且可以使用自己的ModelLoader进行资源加载:
using(ModelLoader<A, T> modelLoader, Class<T> dataClass)using(final StreamModelLoader<T> modelLoader)using(StreamByteArrayLoader modelLoader)using(final FileDescriptorModelLoader<T> modelLoader)
返回GenericRequestBuilder实例。

GenericRequestBuilder使用

GenericRequestBuilder<ModelType,DataType,ResourceType,TranscodeType>是最顶层的Request Builder,用于处理选项设置和开始一般resource类型资源的加载。其中ModelType是指代表资源的类型,如"http://img.my.csdn.net/uploads/201508/05/1438760757_3588.jpg"这个String就代表了一张图片资源,所以这个ModelType就是String。DataType是指ModelLoader提供的,可以被ResourceDecoder解码的数据类型。ResourceType是指将要加载的resource类型。TranscodeType是指已解码的资源将要被转成的资源类型。

  • thumbnail(float sizeMultiplier). 请求给定系数的缩略图。如果缩略图比全尺寸图先加载完,就显示缩略图,否则就不显示。系数sizeMultiplier必须在(0,1)之间,可以递归调用该方法。
  • sizeMultiplier(float sizeMultiplier). 在加载资源之前给Target大小设置系数。
  • diskCacheStrategy(DiskCacheStrategy strategy).设置缓存策略。DiskCacheStrategy.SOURCE:缓存原始数据,DiskCacheStrategy.RESULT:缓存变换(如缩放、裁剪等)后的资源数据,DiskCacheStrategy.NONE:什么都不缓存,DiskCacheStrategy.ALL:缓存SOURC和RESULT。默认采用DiskCacheStrategy.RESULT策略,对于download only操作要使用DiskCacheStrategy.SOURCE。
  • priority(Priority priority). 指定加载的优先级,优先级越高越优先加载,但不保证所有图片都按序加载。枚举Priority.IMMEDIATE,Priority.HIGH,Priority.NORMAL,Priority.LOW。默认为Priority.NORMAL。
  • dontAnimate(). 移除所有的动画。
  • animate(int animationId). 在异步加载资源完成时会执行该动画。
  • animate(ViewPropertyAnimation.Animator animator). 在异步加载资源完成时会执行该动画。
  • placeholder(int resourceId). 设置资源加载过程中的占位Drawable。
  • placeholder(Drawable drawable). 设置资源加载过程中的占位Drawable。
  • fallback(int resourceId). 设置model为空时要显示的Drawable。如果没设置fallback,model为空时将显示error的Drawable,如果error的Drawable也没设置,就显示placeholder的Drawable。
  • fallback(Drawable drawable).设置model为空时显示的Drawable。
  • error(int resourceId).设置load失败时显示的Drawable。
  • error(Drawable drawable).设置load失败时显示的Drawable。
  • listener(RequestListener<? super ModelType, TranscodeType> requestListener). 监听资源加载的请求状态,可以使用两个回调:onResourceReady(R resource, T model, Target<R> target, boolean isFromMemoryCache, boolean isFirstResource)onException(Exception e, T model, Target&lt;R&gt; target, boolean isFirstResource),但不要每次请求都使用新的监听器,要避免不必要的内存申请,可以使用单例进行统一的异常监听和处理。
  • skipMemoryCache(boolean skip). 设置是否跳过内存缓存,但不保证一定不被缓存(比如请求已经在加载资源且没设置跳过内存缓存,这个资源就会被缓存在内存中)。
  • override(int width, int height). 重新设置Target的宽高值(单位为pixel)。
  • into(Y target).设置资源将被加载到的Target。
  • into(ImageView view). 设置资源将被加载到的ImageView。取消该ImageView之前所有的加载并释放资源。
  • into(int width, int height). 后台线程加载时要加载资源的宽高值(单位为pixel)。
  • preload(int width, int height). 预加载resource到缓存中(单位为pixel)。
  • asBitmap(). 无论资源是不是gif动画,都作为Bitmap对待。如果是gif动画会停在第一帧。
  • asGif().把资源作为GifDrawable对待。如果资源不是gif动画将会失败,会回调.error()

技巧

  1. 禁止内存缓存:

    <code class="language-java hljs  has-numbering">    .skipMemoryCache(<span class="hljs-keyword">true</span>)</code><ul class="pre-numbering"><li>1</li></ul>
  2. 清除内存缓存:

    <code class="language-java hljs  has-numbering">    <span class="hljs-comment">// 必须在UI线程中调用</span>    Glide.get(context).clearMemory();</code><ul class="pre-numbering"><li>1</li><li>2</li></ul>
  3. 禁止磁盘缓存:

    <code class="language-java hljs  has-numbering">   .diskCacheStrategy(DiskCacheStrategy.NONE)</code><ul class="pre-numbering"><li>1</li></ul>
  4. 清除磁盘缓存:

    <code class="language-java hljs  has-numbering">   <span class="hljs-comment">// 必须在后台线程中调用,建议同时clearMemory()</span>   Glide.get(applicationContext).clearDiskCache();</code><ul class="pre-numbering"><li>1</li><li>2</li></ul>
  5. 获取缓存大小:

    <code class="language-java hljs  has-numbering">   <span class="hljs-keyword">new</span> GetDiskCacheSizeTask(textView).execute(<span class="hljs-keyword">new</span> File(getCacheDir(), DiskCache.Factory.DEFAULT_DISK_CACHE_DIR));</code><ul class="pre-numbering"><li>1</li></ul>
    <code class="language-java hljs  has-numbering">class GetDiskCacheSizeTask extends AsyncTask<File, Long, Long> {<span class="hljs-keyword">private</span> <span class="hljs-keyword">final</span> TextView resultView;<span class="hljs-keyword">public</span> <span class="hljs-title">GetDiskCacheSizeTask</span>(TextView resultView) {    <span class="hljs-keyword">this</span>.resultView = resultView;}<span class="hljs-annotation">@Override</span><span class="hljs-keyword">protected</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onPreExecute</span>() {    resultView.setText(<span class="hljs-string">"Calculating..."</span>);}<span class="hljs-annotation">@Override</span><span class="hljs-keyword">protected</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onProgressUpdate</span>(Long... values) { <span class="hljs-comment">/* onPostExecute(values[values.length - 1]); */</span> }<span class="hljs-annotation">@Override</span><span class="hljs-keyword">protected</span> Long <span class="hljs-title">doInBackground</span>(File... dirs) {    <span class="hljs-keyword">try</span> {        <span class="hljs-keyword">long</span> totalSize = <span class="hljs-number">0</span>;        <span class="hljs-keyword">for</span> (File dir : dirs) {            publishProgress(totalSize);            totalSize += calculateSize(dir);        }        <span class="hljs-keyword">return</span> totalSize;    } <span class="hljs-keyword">catch</span> (RuntimeException ex) {        <span class="hljs-keyword">final</span> String message = String.format(<span class="hljs-string">"Cannot get size of %s: %s"</span>, Arrays.toString(dirs), ex);        <span class="hljs-keyword">new</span> Handler(Looper.getMainLooper()).post(<span class="hljs-keyword">new</span> Runnable() {            <span class="hljs-annotation">@Override</span>            <span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">run</span>() {                resultView.setText(<span class="hljs-string">"error"</span>);                Toast.makeText(resultView.getContext(), message, Toast.LENGTH_LONG).show();            }        });    }    <span class="hljs-keyword">return</span> <span class="hljs-number">0</span>L;}<span class="hljs-annotation">@Override</span><span class="hljs-keyword">protected</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onPostExecute</span>(Long size) {    String sizeText = android.text.format.Formatter.formatFileSize(resultView.getContext(), size);    resultView.setText(sizeText);}<span class="hljs-keyword">private</span> <span class="hljs-keyword">static</span> <span class="hljs-keyword">long</span> <span class="hljs-title">calculateSize</span>(File dir) {    <span class="hljs-keyword">if</span> (dir == <span class="hljs-keyword">null</span>) <span class="hljs-keyword">return</span> <span class="hljs-number">0</span>;    <span class="hljs-keyword">if</span> (!dir.isDirectory()) <span class="hljs-keyword">return</span> dir.length();    <span class="hljs-keyword">long</span> result = <span class="hljs-number">0</span>;    File[] children = dir.listFiles();    <span class="hljs-keyword">if</span> (children != <span class="hljs-keyword">null</span>)        <span class="hljs-keyword">for</span> (File child : children)            result += calculateSize(child);    <span class="hljs-keyword">return</span> result;}}</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li><li>21</li><li>22</li><li>23</li><li>24</li><li>25</li><li>26</li><li>27</li><li>28</li><li>29</li><li>30</li><li>31</li><li>32</li><li>33</li><li>34</li><li>35</li><li>36</li><li>37</li><li>38</li><li>39</li><li>40</li><li>41</li><li>42</li><li>43</li><li>44</li><li>45</li><li>46</li><li>47</li><li>48</li><li>49</li><li>50</li><li>51</li><li>52</li><li>53</li><li>54</li></ul>
  6. 指定资源的优先加载顺序:

    <code class="language-java hljs  has-numbering">    <span class="hljs-comment">//优先加载</span>    Glide        .with(context)        .load(heroImageUrl)        .priority(Priority.HIGH)        .into(imageViewHero);    <span class="hljs-comment">//后加载</span>    Glide        .with(context)        .load(itemImageUrl)        .priority(Priority.LOW)        .into(imageViewItem);</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li></ul>
  7. 先显示缩略图,再显示原图:

    <code class="language-java hljs  has-numbering">    <span class="hljs-comment">//用原图的1/10作为缩略图</span>    Glide        .with(<span class="hljs-keyword">this</span>)        .load(<span class="hljs-string">"http://inthecheesefactory.com/uploads/source/nestedfragment/fragments.png"</span>)        .thumbnail(<span class="hljs-number">0.1</span>f)        .into(iv_0);    <span class="hljs-comment">//用其它图片作为缩略图</span>    DrawableRequestBuilder<Integer> thumbnailRequest = Glide        .with(<span class="hljs-keyword">this</span>)        .load(R.drawable.news);    Glide.with(<span class="hljs-keyword">this</span>)        .load(<span class="hljs-string">"http://inthecheesefactory.com/uploads/source/nestedfragment/fragments.png"</span>)        .thumbnail(thumbnailRequest)        .into(iv_0);</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li></ul>
  8. 对图片进行裁剪、模糊、滤镜等处理:
    推荐使用独立的图片处理库:wasabeef/glide-transformations,使用也很简单:

    <code class="language-gradle hljs bash has-numbering">    compile <span class="hljs-string">'jp.wasabeef:glide-transformations:2.0.0'</span></code><ul class="pre-numbering"><li>1</li></ul>

    之后我们就可以使用GenericRequestBuilder或其子类的transform()bitmapTransform()方法设置图片转换了:

    <code class="language-java hljs  has-numbering">    <span class="hljs-comment">//圆形裁剪</span>    Glide.with(<span class="hljs-keyword">this</span>)        .load(<span class="hljs-string">"http://inthecheesefactory.com/uploads/source/nestedfragment/fragments.png"</span>)        .bitmapTransform(<span class="hljs-keyword">new</span> CropCircleTransformation(<span class="hljs-keyword">this</span>))        .into(iv_0);    <span class="hljs-comment">//圆角处理</span>    Glide.with(<span class="hljs-keyword">this</span>)        .load(<span class="hljs-string">"http://inthecheesefactory.com/uploads/source/nestedfragment/fragments.png"</span>)        .bitmapTransform(<span class="hljs-keyword">new</span> RoundedCornersTransformation(<span class="hljs-keyword">this</span>,<span class="hljs-number">30</span>,<span class="hljs-number">0</span>, RoundedCornersTransformation.CornerType.ALL))        .into(iv_0);    <span class="hljs-comment">//灰度处理</span>    Glide.with(<span class="hljs-keyword">this</span>)        .load(<span class="hljs-string">"http://inthecheesefactory.com/uploads/source/nestedfragment/fragments.png"</span>)        .bitmapTransform(<span class="hljs-keyword">new</span> GrayscaleTransformation(<span class="hljs-keyword">this</span>))        .into(iv_0);    <span class="hljs-comment">//其它变换...</span></code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li></ul>

    可根据情况使用GenericRequestBuilder子类DrawableRequestBuilder的bitmapTransform(Transformation<Bitmap>... bitmapTransformations)transform(BitmapTransformation... transformations)transform(Transformation<GifBitmapWrapper>... transformation),或其子类BitmapRequestBuilder的transform(BitmapTransformation... transformations)transform(Transformation<Bitmap>... transformations)方法。
    当然如果想自己写Transformation:
    最简单的方式就是继承BitmapTransformation

    <code class="language-java hljs  has-numbering"><span class="hljs-keyword">private</span> <span class="hljs-keyword">static</span> <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">MyTransformation</span> <span class="hljs-keyword">extends</span> <span class="hljs-title">BitmapTransformation</span> {</span>    <span class="hljs-keyword">public</span> <span class="hljs-title">MyTransformation</span>(Context context) {        <span class="hljs-keyword">super</span>(context);    }    <span class="hljs-annotation">@Override</span>    <span class="hljs-keyword">protected</span> Bitmap <span class="hljs-title">transform</span>(BitmapPool pool, Bitmap toTransform,             <span class="hljs-keyword">int</span> outWidth, <span class="hljs-keyword">int</span> outHeight) {       Bitmap myTransformedBitmap = ... <span class="hljs-comment">//对Bitmap进行各种变换处理。</span>       <span class="hljs-keyword">return</span> myTransformedBitmap;    }    <span class="hljs-annotation">@Override</span>    <span class="hljs-keyword">public</span> String <span class="hljs-title">getId</span>() {        <span class="hljs-comment">// 返回代表该变换的唯一Id,会作为cache key的一部分。</span>        <span class="hljs-comment">// 注意:最好不要用getClass().getName(),因为容易受混淆影响。如果变换过程不影响缓存数据,可以返回空字符串。</span>        <span class="hljs-keyword">return</span> <span class="hljs-string">"com.example.myapp.MyTransformation"</span>;    }}</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li></ul>

    使用时只需使用transform()bitmapTransform()方法即可:

    <code class="language-java hljs  has-numbering">Glide.with(yourFragment)    .load(yourUrl)    .asBitmap()    .transform(<span class="hljs-keyword">new</span> MyTransformation(context))    .into(yourView);</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li></ul>

    自定义图片处理时Glide会自动计算View/Target大小,我们不需要传View的宽高,当然你可以使用override(int, int)去改变这种行为。

    自定义图片处理时,为了避免创建大量Bitmap以及减少GC,可以考虑重用Bitmap,这就需要BitmapPool,典型地就是,从Bitmap池中拿一个Bitmap,用这个Bitmap生成一个Canvas, 然后在这个Canvas上画初始的Bitmap并使用Matrix、Paint、或者Shader处理这张图片。
    为了有效并正确重用Bitmap需要遵循以下三条准则:

    1. 永远不要把transform()传给你的原始resource或原始Bitmap给recycle()了,更不要放回BitmapPool,因为这些都自动完成了。值得注意的是,任何从BitmapPool取出的用于自定义图片变换的辅助Bitmap,如果不经过transform()方法返回,就必须主动放回BitmapPool或者调用recycle()回收。
    2. 如果你从BitmapPool拿出多个Bitmap或不使用你从BitmapPool拿出的一个Bitmap,一定要返回extras给BitmapPool。
    3. 如果你的图片处理没有替换原始resource(例如由于一张图片已经匹配了你想要的尺寸,你需要提前返回), transform()`方法就返回原始resource或原始Bitmap。
      如:
    <code class="language-java hljs  has-numbering">    <span class="hljs-keyword">private</span> <span class="hljs-keyword">static</span> <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">MyTransformation</span> <span class="hljs-keyword">extends</span> <span class="hljs-title">BitmapTransformation</span> {</span>        <span class="hljs-keyword">public</span> <span class="hljs-title">MyTransformation</span>(Context context) {            <span class="hljs-keyword">super</span>(context);        }        <span class="hljs-annotation">@Override</span>        <span class="hljs-keyword">protected</span> Bitmap <span class="hljs-title">transform</span>(BitmapPool pool, Bitmap toTransform, <span class="hljs-keyword">int</span> outWidth, <span class="hljs-keyword">int</span> outHeight) {            Bitmap result = pool.get(outWidth, outHeight, Bitmap.Config.ARGB_8888);            <span class="hljs-comment">// 如果BitmapPool中找不到符合该条件的Bitmap,get()方法会返回null,就需要我们自己创建Bitmap了</span>            <span class="hljs-keyword">if</span> (result == <span class="hljs-keyword">null</span>) {                <span class="hljs-comment">// 如果想让Bitmap支持透明度,就需要使用ARGB_8888</span>                result = Bitmap.createBitmap(outWidth, outHeight, Bitmap.Config.ARGB_8888);            }            <span class="hljs-comment">//创建最终Bitmap的Canvas.</span>            Canvas canvas = <span class="hljs-keyword">new</span> Canvas(result);            Paint paint = <span class="hljs-keyword">new</span> Paint();            paint.setAlpha(<span class="hljs-number">128</span>);            <span class="hljs-comment">// 将原始Bitmap处理后画到最终Bitmap中</span>            canvas.drawBitmap(toTransform, <span class="hljs-number">0</span>, <span class="hljs-number">0</span>, paint);            <span class="hljs-comment">// 由于我们的图片处理替换了原始Bitmap,就return我们新的Bitmap就行。</span>            <span class="hljs-comment">// Glide会自动帮我们回收原始Bitmap。</span>            <span class="hljs-keyword">return</span> result;        }        <span class="hljs-annotation">@Override</span>        <span class="hljs-keyword">public</span> String <span class="hljs-title">getId</span>() {            <span class="hljs-comment">// Return some id that uniquely identifies your transformation.</span>            <span class="hljs-keyword">return</span> <span class="hljs-string">"com.example.myapp.MyTransformation"</span>;        }    }</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li><li>21</li><li>22</li><li>23</li><li>24</li><li>25</li><li>26</li><li>27</li><li>28</li><li>29</li><li>30</li><li>31</li></ul>

    也可以直接实现Transformation接口,进行更灵活的图片处理,如进行简单地圆角处理:

    <code class="language-java hljs  has-numbering"><span class="hljs-keyword">public</span> <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">RoundedCornersTransformation</span>  <span class="hljs-keyword">implements</span> <span class="hljs-title">Transformation</span><<span class="hljs-title">Bitmap</span>> {</span>    <span class="hljs-keyword">private</span> BitmapPool mBitmapPool;    <span class="hljs-keyword">private</span> <span class="hljs-keyword">int</span> mRadius;    <span class="hljs-keyword">public</span> <span class="hljs-title">RoundedCornersTransformation</span>(Context context, <span class="hljs-keyword">int</span> mRadius) {        <span class="hljs-keyword">this</span>(Glide.get(context).getBitmapPool(), mRadius);    }    <span class="hljs-keyword">public</span> <span class="hljs-title">RoundedCornersTransformation</span>(BitmapPool mBitmapPool, <span class="hljs-keyword">int</span> mRadius) {        <span class="hljs-keyword">this</span>.mBitmapPool = mBitmapPool;        <span class="hljs-keyword">this</span>.mRadius = mRadius;    }    <span class="hljs-annotation">@Override</span>    <span class="hljs-keyword">public</span> Resource<Bitmap> <span class="hljs-title">transform</span>(Resource<Bitmap> resource, <span class="hljs-keyword">int</span> outWidth, <span class="hljs-keyword">int</span> outHeight) {        <span class="hljs-comment">//从其包装类中拿出Bitmap</span>        Bitmap source = resource.get();        <span class="hljs-keyword">int</span> width = source.getWidth();        <span class="hljs-keyword">int</span> height = source.getHeight();        Bitmap result = mBitmapPool.get(width, height, Bitmap.Config.ARGB_8888);        <span class="hljs-keyword">if</span> (result == <span class="hljs-keyword">null</span>) {            result = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);        }        Canvas canvas = <span class="hljs-keyword">new</span> Canvas(result);        <span class="hljs-comment">//以上已经算是教科书式写法了</span>        Paint paint = <span class="hljs-keyword">new</span> Paint();        paint.setAntiAlias(<span class="hljs-keyword">true</span>);        paint.setShader(<span class="hljs-keyword">new</span> BitmapShader(source, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP));        canvas.drawRoundRect(<span class="hljs-keyword">new</span> RectF(<span class="hljs-number">0</span>, <span class="hljs-number">0</span>, width, height), mRadius, mRadius, paint);        <span class="hljs-comment">//返回包装成Resource的最终Bitmap</span>        <span class="hljs-keyword">return</span> BitmapResource.obtain(result, mBitmapPool);    }    <span class="hljs-annotation">@Override</span>    <span class="hljs-keyword">public</span> String <span class="hljs-title">getId</span>() {        <span class="hljs-keyword">return</span> <span class="hljs-string">"RoundedTransformation(radius="</span> + mRadius + <span class="hljs-string">")"</span>;    }}</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li><li>21</li><li>22</li><li>23</li><li>24</li><li>25</li><li>26</li><li>27</li><li>28</li><li>29</li><li>30</li><li>31</li><li>32</li><li>33</li><li>34</li><li>35</li><li>36</li><li>37</li><li>38</li><li>39</li></ul>
  9. 对请求状态进行监听:

    <code class="language-java hljs  has-numbering"><span class="hljs-keyword">public</span> <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">MainActivity</span> <span class="hljs-keyword">extends</span> <span class="hljs-title">AppCompatActivity</span> {</span>    <span class="hljs-keyword">private</span> <span class="hljs-keyword">static</span> <span class="hljs-keyword">final</span> String TAG = <span class="hljs-string">"MainActivity"</span>;    <span class="hljs-keyword">private</span> ImageView iv_0;    <span class="hljs-keyword">private</span> LoggingListener mCommonRequestListener;    <span class="hljs-annotation">@Override</span>    <span class="hljs-keyword">protected</span> <span class="hljs-keyword">void</span> <span class="hljs-title">onCreate</span>(Bundle savedInstanceState) {        <span class="hljs-keyword">super</span>.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        iv_0 = (ImageView) findViewById(R.id.iv_0);        mCommonRequestListener = <span class="hljs-keyword">new</span> LoggingListener<String, GlideDrawable>();        Glide                .with(<span class="hljs-keyword">this</span>)                .load(<span class="hljs-string">"http://inthecheesefactory.com/uploads/source/nestedfragment/fragments.png"</span>)                .listener(mCommonRequestListener)                .into(iv_0);}}</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li></ul>
    <code class="language-java hljs  has-numbering"><span class="hljs-javadoc">/***<span class="hljs-javadoctag"> @param</span> <A> model类型*<span class="hljs-javadoctag"> @param</span> <B> resource类型*/</span><span class="hljs-keyword">public</span> <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">LoggingListener</span><<span class="hljs-title">A</span>, <span class="hljs-title">B</span>> <span class="hljs-keyword">implements</span> <span class="hljs-title">RequestListener</span><<span class="hljs-title">A</span>, <span class="hljs-title">B</span>> {</span><span class="hljs-keyword">private</span> <span class="hljs-keyword">final</span> <span class="hljs-keyword">int</span> level;<span class="hljs-keyword">private</span> <span class="hljs-keyword">final</span> String name;<span class="hljs-keyword">private</span> <span class="hljs-keyword">final</span> RequestListener<A, B> delegate;<span class="hljs-keyword">public</span> <span class="hljs-title">LoggingListener</span>() {    <span class="hljs-keyword">this</span>(<span class="hljs-string">""</span>);}<span class="hljs-keyword">public</span> <span class="hljs-title">LoggingListener</span>(@NonNull String name) {    <span class="hljs-keyword">this</span>(Log.VERBOSE, name);}<span class="hljs-keyword">public</span> <span class="hljs-title">LoggingListener</span>(<span class="hljs-keyword">int</span> level, @NonNull String name) {    <span class="hljs-keyword">this</span>(level, name, <span class="hljs-keyword">null</span>);}<span class="hljs-keyword">public</span> <span class="hljs-title">LoggingListener</span>(RequestListener<A, B> delegate) {    <span class="hljs-keyword">this</span>(Log.VERBOSE, <span class="hljs-string">""</span>, delegate);}<span class="hljs-keyword">public</span> <span class="hljs-title">LoggingListener</span>(<span class="hljs-keyword">int</span> level, @NonNull String name, RequestListener<A, B> delegate) {    <span class="hljs-keyword">this</span>.level = level;    <span class="hljs-keyword">this</span>.name = name;    <span class="hljs-keyword">this</span>.delegate = delegate == <span class="hljs-keyword">null</span> ? NoOpRequestListener.<A, B>get() : delegate;}<span class="hljs-annotation">@Override</span><span class="hljs-keyword">public</span> <span class="hljs-keyword">boolean</span> <span class="hljs-title">onException</span>(Exception e, A model, Target<B> target, <span class="hljs-keyword">boolean</span> isFirstResource) {    android.util.Log.println(level, <span class="hljs-string">"GLIDE"</span>, String.format(Locale.ROOT,            <span class="hljs-string">"%s.onException(%s, %s, %s, %s)\n%s"</span>,            name, e, model, strip(target), isFirst(isFirstResource), android.util.Log.getStackTraceString(e)));    <span class="hljs-keyword">return</span> delegate.onException(e, model, target, isFirstResource);}<span class="hljs-annotation">@Override</span><span class="hljs-keyword">public</span> <span class="hljs-keyword">boolean</span> <span class="hljs-title">onResourceReady</span>(B resource, A model, Target<B> target, <span class="hljs-keyword">boolean</span> isFromMemoryCache,                               <span class="hljs-keyword">boolean</span> isFirstResource) {    String resourceString = strip(getResourceDescription(resource));    String targetString = strip(getTargetDescription(target));    android.util.Log.println(level, <span class="hljs-string">"GLIDE"</span>, String.format(Locale.ROOT,            <span class="hljs-string">"%s.onResourceReady(%s, %s, %s, %s, %s)"</span>,            name, resourceString, model, targetString, isMem(isFromMemoryCache), isFirst(isFirstResource)));    <span class="hljs-keyword">return</span> delegate.onResourceReady(resource, model, target, isFromMemoryCache, isFirstResource);}<span class="hljs-keyword">private</span> String <span class="hljs-title">isMem</span>(<span class="hljs-keyword">boolean</span> isFromMemoryCache) {    <span class="hljs-keyword">return</span> isFromMemoryCache ? <span class="hljs-string">"sync"</span> : <span class="hljs-string">"async"</span>;}<span class="hljs-keyword">private</span> String <span class="hljs-title">isFirst</span>(<span class="hljs-keyword">boolean</span> isFirstResource) {    <span class="hljs-keyword">return</span> isFirstResource ? <span class="hljs-string">"first"</span> : <span class="hljs-string">"not first"</span>;}<span class="hljs-keyword">private</span> String <span class="hljs-title">getTargetDescription</span>(Target<B> target) {    String result;    <span class="hljs-keyword">if</span> (target <span class="hljs-keyword">instanceof</span> ViewTarget) {        View v = ((ViewTarget) target).getView();        LayoutParams p = v.getLayoutParams();        result = String.format(Locale.ROOT,                <span class="hljs-string">"%s(params=%dx%d->size=%dx%d)"</span>, target, p.width, p.height, v.getWidth(), v.getHeight());    } <span class="hljs-keyword">else</span> {        result = String.valueOf(target);    }    <span class="hljs-keyword">return</span> result;}<span class="hljs-keyword">private</span> String <span class="hljs-title">getResourceDescription</span>(B resource) {    String result;    <span class="hljs-keyword">if</span> (resource <span class="hljs-keyword">instanceof</span> Bitmap) {        Bitmap bm = (Bitmap) resource;        result = String.format(Locale.ROOT,                <span class="hljs-string">"%s(%dx%d@%s)"</span>, resource, bm.getWidth(), bm.getHeight(), bm.getConfig());    } <span class="hljs-keyword">else</span> <span class="hljs-keyword">if</span> (resource <span class="hljs-keyword">instanceof</span> BitmapDrawable) {        Bitmap bm = ((BitmapDrawable) resource).getBitmap();        result = String.format(Locale.ROOT,                <span class="hljs-string">"%s(%dx%d@%s)"</span>, resource, bm.getWidth(), bm.getHeight(), bm.getConfig());    } <span class="hljs-keyword">else</span> <span class="hljs-keyword">if</span> (resource <span class="hljs-keyword">instanceof</span> GlideBitmapDrawable) {        Bitmap bm = ((GlideBitmapDrawable) resource).getBitmap();        result = String.format(Locale.ROOT,                <span class="hljs-string">"%s(%dx%d@%s)"</span>, resource, bm.getWidth(), bm.getHeight(), bm.getConfig());    } <span class="hljs-keyword">else</span> <span class="hljs-keyword">if</span> (resource <span class="hljs-keyword">instanceof</span> Drawable) {        Drawable d = (Drawable) resource;        result = String.format(Locale.ROOT,                <span class="hljs-string">"%s(%dx%d)"</span>, resource, d.getIntrinsicWidth(), d.getIntrinsicHeight());    } <span class="hljs-keyword">else</span> {        result = String.valueOf(resource);    }    <span class="hljs-keyword">return</span> result;}<span class="hljs-keyword">private</span> <span class="hljs-keyword">static</span> String <span class="hljs-title">strip</span>(Object text) {    <span class="hljs-keyword">return</span> String.valueOf(text).replaceAll(<span class="hljs-string">"(com|android|net|org)(\\.[a-z]+)+\\."</span>, <span class="hljs-string">""</span>);}}</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li><li>21</li><li>22</li><li>23</li><li>24</li><li>25</li><li>26</li><li>27</li><li>28</li><li>29</li><li>30</li><li>31</li><li>32</li><li>33</li><li>34</li><li>35</li><li>36</li><li>37</li><li>38</li><li>39</li><li>40</li><li>41</li><li>42</li><li>43</li><li>44</li><li>45</li><li>46</li><li>47</li><li>48</li><li>49</li><li>50</li><li>51</li><li>52</li><li>53</li><li>54</li><li>55</li><li>56</li><li>57</li><li>58</li><li>59</li><li>60</li><li>61</li><li>62</li><li>63</li><li>64</li><li>65</li><li>66</li><li>67</li><li>68</li><li>69</li><li>70</li><li>71</li><li>72</li><li>73</li><li>74</li><li>75</li><li>76</li><li>77</li><li>78</li><li>79</li><li>80</li><li>81</li><li>82</li><li>83</li><li>84</li><li>85</li><li>86</li><li>87</li><li>88</li><li>89</li><li>90</li><li>91</li><li>92</li><li>93</li><li>94</li><li>95</li><li>96</li><li>97</li><li>98</li><li>99</li></ul>
    <code class="language-java hljs  has-numbering"><span class="hljs-keyword">public</span> <span class="hljs-keyword">final</span> <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">NoOpRequestListener</span><<span class="hljs-title">A</span>, <span class="hljs-title">B</span>> <span class="hljs-keyword">implements</span> <span class="hljs-title">RequestListener</span><<span class="hljs-title">A</span>, <span class="hljs-title">B</span>> {</span><span class="hljs-keyword">private</span> <span class="hljs-keyword">static</span> <span class="hljs-keyword">final</span> RequestListener INSTANCE = <span class="hljs-keyword">new</span> NoOpRequestListener();<span class="hljs-annotation">@SuppressWarnings</span>(<span class="hljs-string">"unchecked"</span>)<span class="hljs-keyword">public</span> <span class="hljs-keyword">static</span> <A, B> RequestListener<A, B> <span class="hljs-title">get</span>() {    <span class="hljs-keyword">return</span> INSTANCE;}<span class="hljs-keyword">private</span> <span class="hljs-title">NoOpRequestListener</span>() {}<span class="hljs-annotation">@Override</span> <span class="hljs-keyword">public</span> <span class="hljs-keyword">boolean</span> <span class="hljs-title">onException</span>(Exception e, A a, Target<B> target, <span class="hljs-keyword">boolean</span> b) {    <span class="hljs-keyword">return</span> <span class="hljs-keyword">false</span>;}<span class="hljs-annotation">@Override</span> <span class="hljs-keyword">public</span> <span class="hljs-keyword">boolean</span> <span class="hljs-title">onResourceReady</span>(B b, A a, Target<B> target, <span class="hljs-keyword">boolean</span> b2, <span class="hljs-keyword">boolean</span> b1) {    <span class="hljs-keyword">return</span> <span class="hljs-keyword">false</span>;}}</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li></ul>

    通过GenericRequestBuilder的listener()方法添加一个RequestListener实现,但要注意,最好不要用匿名类,也不要每次都创建新的监听器,要使用单例进行统一监听处理,以避免不必要的内存申请和不必要的引用。方法最好返回false,以便Glide能继续进行后续处理(如显示error占位符)。

  10. 对资源的下载进度进行监听:
    可以借助OkHttp的拦截器进行进度监听。OkHttp的拦截器官方Sample请移步这里。我们可以利用这个拦截器进行监听并处理,需要自定义ModelLoader和DataFetcher,具体请详见我的Git:https://github.com/shangmingchao/ProgressGlide,欢迎Star啊,不过没有太大必要告诉用户图片加载的进度(sjudd和TWiStErRob他们说的)。同时也可以看一下TWiStErRob大神的实现(自备梯子哈~.~)。

想了解更多,可以看一下这几篇文章:

  • Glide使用详解(二)
  • Glide之GlideModule
  • Glide之Target
  • Glide之后台线程加载及缓存资源
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