Android——动态加载资源布局

原文链接：http://blog.csdn.net/chenliguan/article/details/47294925

一、动态加载与静态加载的区别

1、动态加载是一种优化，降低资源的耗费。偶尔，在布局中会有一些比较复杂但是又很少用到的控件。不管它是消息详情，进度条还是未完成的提示信息，你都可以直到真正需要的时候再加载他们，以降低你的内存消耗，提升渲染效率。

2、动态布局，也就是可以根据业务的需求改变界面。实际上就是用代码写出界面，代码量比较大。而且维护起来十分的繁琐。特别是一些界面空间比较多的时候。静态的布局，是通过xml来实现的，适用于页面比较固定的情况。但是维护起来比较方便。

二、使用inflater来实现动态加载布局

1、在Activity、Fragment等中可获取到getLayoutInflater()

<code class="hljs avrasm has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">LayoutInflater _inflater = getLayoutInflater()<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>View _view = _inflater<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.inflate</span>(R<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.layout</span><span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.activity</span>_main, null)<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>setContentView(_view)<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul>

2、在Adapter中不能获取到getLayoutInflater()，通过上下文获取

<code class="hljs avrasm has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">LayoutInflater _inflater = LayoutInflater<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.from</span>(mContext)<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>View view = _inflater<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.inflate</span>(R<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.layout</span><span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.activity</span>_main, null)<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>setContentView(_view)<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li></ul>

三、在布局中动态添加组件

1、例子1

<code class="hljs java has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">    <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 1、获取根布局属性</span>    FrameLayout _frameLayout = (FrameLayout) findViewById(R.id.flyt_main);    <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 2、获取组件，设置组件属性</span>    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">final</span> Button _button = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Button(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>);    _button.setText(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"跳转到TwoActivity"</span>);    <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 3、在布局中添加组件，设置组件属性</span>_frameLayout.addView(_button,LayoutParams.FILL_PARENT,LayoutParams.FILL_PARENT);</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li></ul>

2、例子2

<code class="hljs java has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">    <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 1、获取根布局属性</span>    FrameLayout _frameLayout = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> FrameLayout(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>);    <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 2、获取组件，设置组件属性</span>    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">final</span> Button _button = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Button(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>);    _button.setText(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"跳转到TwoActivity"</span>);    <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 3、在布局中添加组件，设置组件属性</span> _frameLayout.addView(_button,LayoutParams.FILL_PARENT,LayoutParams.FILL_PARENT);    <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 4、调用Window.setContentView()加载界面</span>    setContentView(_frameLayout);</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li></ul>

3、例子3

<code class="hljs cs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">protected</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">AppendMainBody</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> pResID) {        <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 1、获取根布局属性</span>        LinearLayout _mainBody = (LinearLayout) findViewById(R.id.llyt_main_body);        <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 2、获取组件，设置组件属性</span>        View _view = LayoutInflater.<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">from</span>(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">this</span>).inflate(pResID,<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>);        <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 3、在布局中添加组件，设置组件属性</span>        _mainBody.addView(_view, RelativeLayout.LayoutParams.FILL_PARENT, RelativeLayout.LayoutParams.FILL_PARENT);    }</code>