Android自定义ImageView实现自动放大缩小动画

Android自定义ImageView实现自动放大缩小动画

转载 :https://www.jb51.net/article/116326.htm

 

这篇文章主要为大家详细介绍了Android自定义ImageView实现自动放大缩小动画，具有一定的参考价值，感兴趣的小伙伴们可以参考一下

这篇讲的是如何生成一个自定义的ImageView，实现自动放大缩小动画。 

为什么实现这个功能呢？因为我想在ViewPager实现图片放大缩小的动画，但是ViewPager几个页面的动画会一起动，而且放大全屏图片的话会相互覆盖，很诡异。于是上网搜demo，一无所获。迫于无奈。。。 
废话不多说，直接贴代码。

1.配置文件直接添加

当直接在布局文件中添加图片的话，可以在自定义View代码中用getDrawable（）获取图片资源，然后通过DrawBitmap绘制图片。通过不断绘制图片的位置，达到放大缩小的功能。 
第一种情况实在XML布局文件中直接添加的：

 

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95

public class CoolImageView extends ImageView {     private int mLeft = 0;   private int mTop = 0;   private Handler mHandler;   private Bitmap bitmap;   private Rect srcRect = new Rect();   private Rect dstRect = new Rect();   private int imgWidth;   private int imgHeight;   private boolean flag;   private boolean istart;     public CoolImageView(Context context) {     super(context);   }     public CoolImageView(Context context, AttributeSet attrs) {     super(context, attrs);     setUp(context, attrs);   }     public CoolImageView(Context context, AttributeSet attrs, int defStyleAttr) {     super(context, attrs, defStyleAttr);     setUp(context, attrs);   }       private void setUp(Context context, AttributeSet attrs) {     mHandler = new MoveHandler();     mHandler.sendEmptyMessageDelayed(1, 220L);     istart = true;   }     @Override   protected void onDraw(Canvas canvas) {     super.onDraw(canvas);     int width = getWidth();     int height = getHeight();     //获取图片资源     BitmapDrawable drawable = (BitmapDrawable) getDrawable();     bitmap = drawable.getBitmap();     dstRect.left = 0;     dstRect.top = 0;     dstRect.right = width;     dstRect.bottom = height;     if (bitmap != null) {       if (istart) { //        获取图片的宽高         imgWidth = bitmap.getWidth();         imgHeight = bitmap.getHeight();         srcRect.left = 0 + mLeft;         srcRect.right = imgWidth - mLeft;         srcRect.top = 0 + mTop;         srcRect.bottom = imgHeight - mTop;         canvas.drawBitmap(bitmap, srcRect, dstRect, null);       } else {         canvas.drawBitmap(bitmap, null, dstRect, null);       }     }     }     private class MoveHandler extends Handler {     @Override     public void handleMessage(Message msg) {       switch (msg.what) {         case 1:           if (imgHeight != 0) {             if (mTop == 0) {               mTop += 5;               mLeft += 5;             } else if (mTop == 120) {               mTop -= 5;               mLeft -= 5;             }           }           postInvalidate();           mHandler.sendEmptyMessageDelayed(1, 250);           break;       }     }   }     public void start() {     mTop = 0;     mLeft = 0;     istart = true;     mHandler.sendEmptyMessageDelayed(1, 220L);   }     public void stop() {     istart = false;   } }

2 .通过Glide加载图片的方式

通过Glide加载图片的话，不能直接用getDrawable获取图片资源。Glide加载图片的方式也需要改变。废话不多说，直接上代码。 
CoolimageView直接从Glide的缓存中加载图片。

?

1 2 3 4 5 6 7 8 9 10

Glide.with(GoodsPagerActivity.this)             .load(sList.get(position).img)             .override(width, height)             .centerCrop()             .into(new SimpleTarget() {               @Override               public void onResourceReady(GlideDrawable resource, GlideAnimationsuper GlideDrawable> glideAnimation) {                 imageView.setImageDrawable(resource);               }             });

CoolImageView.java:
唯一不同的是获取图片的方式；
```java

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115

public class CoolImageView extends ImageView {       private int mLeft = 0;   private int mTop = 0;   private Handler mHandler;   private Bitmap bitmap;   private Rect srcRect = new Rect();   private Rect dstRect = new Rect();   private int imgWidth;   private int imgHeight;   private boolean flag;   private boolean istart;   private int width;   private int height;     public CoolImageView(Context context) {     super(context);   }     public CoolImageView(Context context, AttributeSet attrs) {     super(context, attrs);     setUp(context, attrs);   }     public CoolImageView(Context context, AttributeSet attrs, int defStyleAttr) {     super(context, attrs, defStyleAttr);     setUp(context, attrs);   }       private void setUp(Context context, AttributeSet attrs) {     mHandler = new MoveHandler();     mHandler.sendEmptyMessageDelayed(1, 220L);     istart = true;   }     @Override   public void setImageDrawable(@Nullable Drawable drawable) {     super.setImageDrawable(drawable);     if (mHandler != null) {       mHandler.sendEmptyMessageDelayed(1, 220L);     } else {       mHandler = new MoveHandler();       mHandler.sendEmptyMessageDelayed(1, 220L);       istart = true;     }   }     @Override   protected void onDraw(Canvas canvas) {     super.onDraw(canvas);     width = getWidth();     height = getHeight();     GlideBitmapDrawable drawable = (GlideBitmapDrawable) getDrawable();     if (drawable != null) {       bitmap = drawable.getBitmap();     }     dstRect.left = 0;     dstRect.top = 0;     dstRect.right = width;     dstRect.bottom = height;     if (bitmap != null) {       if (istart) {         imgWidth = bitmap.getWidth();         imgHeight = bitmap.getHeight();         srcRect.left = 0 + mLeft;         srcRect.right = imgWidth - mLeft;         srcRect.top = 0 + mTop;         srcRect.bottom = imgHeight - mTop;         canvas.drawBitmap(bitmap, srcRect, dstRect, null);       } else {         canvas.drawBitmap(bitmap, null, dstRect, null);       }     }     }     private class MoveHandler extends Handler {     @Override     public void handleMessage(Message msg) {       switch (msg.what) {         case 1:           if (imgHeight != 0) {             if (mTop == 0) {               flag = true;             } else if (mTop == 60) {               flag = false;             }             if (!flag) {               mTop -= 2;               mLeft -= 1;             } else {               mTop += 2;               mLeft += 1;             }           }           postInvalidate();           mHandler.sendEmptyMessageDelayed(1, 200);           break;       }     }   }     public void start() {     mTop = 0;     mLeft = 0;     istart = true;     mHandler.sendEmptyMessageDelayed(1, 220L);   }     public void stop() {     istart = false;   } }

如果感觉动画不够流畅可以缩小线程等待时间。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。