仿小红书根据图片高度自适应viewpager高度轮播图

来源：互联网发布：恒扬数据股份有限公司编辑：程序博客网时间：2024/06/05 10:26

源码地址：http://download.csdn.net/detail/qq_34262695/9805267

之前不了解小红书，直到有一天经理说看见一个他想要的效果，跟小红书一样，赶紧下载小红书来看看，写起来贼费劲的一个自适应viewpager高度的轮播图。

效果图:

直接粘代码了：main_activity

<?xml version="1.0" encoding="utf-8"?><ScrollView xmlns:android="http://schemas.android.com/apk/res/android"    android:id="@+id/activity_main"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:fillViewport="true"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin">    <LinearLayout        android:layout_width="match_parent"        android:layout_height="match_parent"        android:fillViewport="true"        android:orientation="vertical">        <android.support.v4.view.ViewPager            android:id="@+id/viewpager"            android:layout_width="match_parent"            android:layout_height="wrap_content" />        <TextView            android:layout_width="match_parent"            android:layout_height="800dp"            android:background="#ff4422"            android:text="Hello World!" />    </LinearLayout></ScrollView>

MainActivity：

public class MainActivity extends AppCompatActivity {    private ViewPager mViewpager;    private String[] urls = {            "http://f.hiphotos.baidu.com/zhidao/pic/item/3b87e950352ac65cbdbeff61fcf2b21193138a6d.jpg"            , "http://c.hiphotos.baidu.com/zhidao/pic/item/562c11dfa9ec8a1359aa88b6f103918fa0ecc030.jpg",            "http://c.hiphotos.baidu.com/zhidao/pic/item/faf2b2119313b07e6077d3bc0ad7912396dd8cb8.jpg"    };    private int[] imgheights;    private int screenWidth;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        screenWidth = ScreenUtil.getScreenWidth(this);        initView();    }    public void initView() {        mViewpager = (ViewPager) findViewById(R.id.viewpager);        Glide.with(this).load(urls[0]).asBitmap().into(new SimpleTarget<Bitmap>() {            @Override            public void onResourceReady(Bitmap resource, GlideAnimation<? super Bitmap> glideAnimation) {                float scale = (float) resource.getHeight() / resource.getWidth();                int defaultheight = (int) (scale * screenWidth);                initViewPager(defaultheight);            }        });    }    //获取第一张图片高度后，给viewpager设置adapter    private void initViewPager(final int defaultheight) {        mViewpager.setAdapter(new PagerAdapter() {            @Override            public int getCount() {                if (imgheights == null || imgheights.length != urls.length) {                    imgheights = null;                    imgheights = new int[urls.length];                }                return urls.length;            }            @Override            public Object instantiateItem(ViewGroup container, final int position) {                final ImageView imageView = new ImageView(MainActivity.this);                imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);                Glide.with(getApplicationContext()).load(urls[position]).asBitmap().placeholder(R.mipmap.ic_launcher).into(new ImageViewTarget<Bitmap>(imageView) {                    @Override                    protected void setResource(Bitmap loadedImage) {                        if (loadedImage != null) {                            float scale = (float) loadedImage.getHeight() / loadedImage.getWidth();                            imgheights[position] = (int) (scale * screenWidth);                            imageView.setImageBitmap(loadedImage);                        } else {                            Toast.makeText(MainActivity.this, "图片为空", Toast.LENGTH_LONG).show();                        }                    }                });                container.addView(imageView);                return imageView;            }            @Override            public void destroyItem(ViewGroup container, int position, Object object) {                container.removeView((View) object);            }            @Override            public boolean isViewFromObject(View view, Object object) {                return view == object;            }        });        //为ViewPager设置高度        ViewGroup.LayoutParams params = mViewpager.getLayoutParams();        params.height = defaultheight;        mViewpager.setLayoutParams(params);        mViewpager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {            @Override            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {                if (position == imgheights.length - 1) {                    return;                }                //计算ViewPager现在应该的高度,heights[]表示页面高度的数组。                int height = (int) ((imgheights[position] == 0 ? defaultheight : imgheights[position])                        * (1 - positionOffset) +                        (imgheights[position + 1] == 0 ? defaultheight : imgheights[position + 1])                                * positionOffset);                //为ViewPager设置高度                ViewGroup.LayoutParams params = mViewpager.getLayoutParams();                params.height = height;                mViewpager.setLayoutParams(params);            }            @Override            public void onPageSelected(int position) {            }            @Override            public void onPageScrollStateChanged(int state) {            }        });    }}

还需要一个获得屏幕宽高的工具类:

/** * 获得屏幕宽度 * * @param context * @return */public static int getScreenWidth(Context context) {    WindowManager wm = (WindowManager) context            .getSystemService(Context.WINDOW_SERVICE);    DisplayMetrics outMetrics = new DisplayMetrics();    wm.getDefaultDisplay().getMetrics(outMetrics);    return outMetrics.widthPixels;}/** *获取屏幕高度 */public static int getScreenHight(Context context){    WindowManager wm = (WindowManager) context            .getSystemService(Context.WINDOW_SERVICE);    DisplayMetrics outMetrics = new DisplayMetrics();    wm.getDefaultDisplay().getMetrics(outMetrics);    return outMetrics.heightPixels;}

恩，大概就这样，自己看吧。~~~

源码地址：http://download.csdn.net/detail/qq_34262695/9805267

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