android图片旋转是老话题了，但如何简单迅速无BUG的解决它是需要想一想的。

首先回顾一下android 图片旋转提供的API有哪些

1.Matrix

2.Animation

说白了 Animation的核心也是Matrix。 而且Animation真是扩展性不强也不好用，用过的应该都知道。

那我们开始走Matrix路线吧。下面是游戏中用到的箭头选择并动画在原地来回偏移。

核心代码如下

package com.laahaa.view.extension; import com.laahaa.R; import com.laahaa.config.ExtensionLayoutConfig; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Matrix; import android.graphics.drawable.BitmapDrawable; import android.view.Gravity; import android.widget.FrameLayout; import android.widget.FrameLayout.LayoutParams; import android.widget.ImageView; /**  *  * 
class name:中间箭头
  * 
class instruction:
  * @author Mercury  Create in 2012-2-7 */ public class CenterArrow extends ImageView{
       FrameLayout.LayoutParams lp; private Bitmap bitmap; private Matrix matrix = new Matrix(); public CenterArrow(Context context) {
           super(context);          lp=new FrameLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT,Gravity.CENTER);     } /**      * 线程每次间隔时间调用      * @param dir */ public void onTick(int dir)     {
   switch (dir) {
   case 0: if(lp.bottomMargin==(ExtensionLayoutConfig.CenterArrowWidth+ExtensionLayoutConfig.CenterCircleWidth))                 lp.bottomMargin+=ExtensionLayoutConfig.ArrowOffset; else                 lp.bottomMargin-=ExtensionLayoutConfig.ArrowOffset; break; case 1:            if(lp.leftMargin==(ExtensionLayoutConfig.CenterArrowWidth+ExtensionLayoutConfig.CenterCircleWidth))                 lp.leftMargin+=ExtensionLayoutConfig.ArrowOffset; else                 lp.leftMargin-=ExtensionLayoutConfig.ArrowOffset; break; case 2:        if(lp.bottomMargin==-(ExtensionLayoutConfig.CenterArrowWidth+ExtensionLayoutConfig.CenterCircleWidth))                 lp.bottomMargin-=ExtensionLayoutConfig.ArrowOffset; else                 lp.bottomMargin+=ExtensionLayoutConfig.ArrowOffset; break; case 3: if(lp.leftMargin==-(ExtensionLayoutConfig.CenterArrowWidth+ExtensionLayoutConfig.CenterCircleWidth))                 lp.leftMargin-=ExtensionLayoutConfig.ArrowOffset; else                 lp.leftMargin+=ExtensionLayoutConfig.ArrowOffset; break;         } this.setLayoutParams(lp); this.setImageBitmap(bitmap);     } public void setRotate(int dir)     {
   int degrees=0; switch (dir) {
   case 0:             degrees=90;             lp.leftMargin=0;             lp.rightMargin=0;             lp.bottomMargin=ExtensionLayoutConfig.CenterArrowWidth+ExtensionLayoutConfig.CenterCircleWidth;             lp.topMargin=0; break; case 1:             degrees=0;             lp.leftMargin=ExtensionLayoutConfig.CenterArrowWidth+ExtensionLayoutConfig.CenterCircleWidth;             lp.rightMargin=0;             lp.bottomMargin=0;             lp.topMargin=0; break; case 2:             degrees=270;             lp.leftMargin=0;             lp.rightMargin=0;             lp.bottomMargin=-(ExtensionLayoutConfig.CenterArrowWidth+ExtensionLayoutConfig.CenterCircleWidth);             lp.topMargin=0; break; case 3:             degrees=180;             lp.leftMargin=-(ExtensionLayoutConfig.CenterArrowWidth+ExtensionLayoutConfig.CenterCircleWidth);             lp.rightMargin=0;             lp.bottomMargin=0;             lp.topMargin=0; break;         }          bitmap=((BitmapDrawable) getResources().getDrawable(R.drawable.arrow)).getBitmap();  this.setLayoutParams(lp); //设置图像的旋转角度              matrix.setRotate(degrees); //旋转图像，并生成新的Bitmap对像            bitmap=Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true); //重新在ImageView组件中显示旋转后的图像            this.setImageBitmap(bitmap);     } }