怎么在Android利用Matrix对图片进行旋转

package com.oyp.loadingdisk; 
 
import java.io.InputStream; 
 
import android.content.Context; 
import android.content.res.Resources; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.graphics.Canvas; 
import android.graphics.Matrix; 
import android.graphics.Paint; 
import android.graphics.PaintFlagsDrawFilter; 
import android.view.View; 
/** 
 * 自定义的View,用来显示加载的图片 
 * @author ouyangpeng 
 * @link http://blog.csdn.net/ouyang_peng 
 * 
 * 
在画图的时候，图片如果旋转或缩放之后，总是会出现那些华丽的锯齿。
 
 * 方法一：给Paint加上抗锯齿标志。然后将Paint对象作为参数传给canvas的绘制方法。
 
 * 如：mypaint.setAntiAlias(true);
 
 * 方法二：给Canvas加上抗锯齿标志。有些地方不能用paint的，就直接给canvas加抗锯齿，更方便。
 
 * 如： 
 * mSetfil = new PaintFlagsDrawFilter(0, Paint.FILTER_BITMAP_FLAG);
 
 * canvas.setDrawFilter(mSetfil); 
 */ 
public class LoadingDiscView extends View { 
  private RefreshHandle refreshHandle; 
  private Context context; 
  /** 用于旋转的bitmap*/ 
  private Bitmap m_bmp_disc = null; 
  private Matrix m_matrix_disc = new Matrix(); 
  /** 用于展现高亮背景的bitmap*/ 
  private Bitmap m_bmp_light = null; 
  private Matrix m_matrix_light = new Matrix(); 
  /**Paint滤波器*/ 
  private PaintFlagsDrawFilter mSetfil = null; 
  /**声明一个画笔*/ 
  private Paint mypaint = null; 
  /**图像缩放比例*/ 
  private float m_scale =1.0f; 
  /**图像旋转的速度*/ 
  private float m_disc_rot_speed = 0; 
  /**图像旋转的状态*/ 
  private int m_state_play = 1; 
  /**图像旋转的最大速度*/ 
  private float m_disc_max = 20f; 
 
  public void setRefreshHandle(RefreshHandle refreshHandle) { 
   this.refreshHandle = refreshHandle; 
  } 
 
  public LoadingDiscView(Context context) { 
   super(context); 
   this.context = context; 
   mSetfil = new PaintFlagsDrawFilter(0, Paint.FILTER_BITMAP_FLAG);//设置画布绘图无锯齿 
   initBitmap(); 
  } 
 
  public boolean initBitmap() { 
   mypaint = new Paint(); 
   //给Paint加上抗锯齿标志 
   mypaint.setAntiAlias(true);//画笔的抗锯齿（用于线条等） 
 
   Resources res = context.getResources(); 
   InputStream is = res.openRawResource(R.drawable.loading_disc); 
   m_bmp_disc = BitmapFactory.decodeStream(is); 
   matrixPostTranslate(m_matrix_disc,m_bmp_disc); 
 
   is = res.openRawResource(R.drawable.loading_light); 
   m_bmp_light = BitmapFactory.decodeStream(is); 
   matrixPostTranslate(m_matrix_light,m_bmp_light); 
   return true; 
  } 
  /** 
   * 旋转图像 
   * @param matrix 控制旋转的矩阵 
   * @param bitmap 要旋转的图像 
   */ 
  private void matrixPostTranslate(Matrix matrix,Bitmap bitmap) { 
   int tmp_width = bitmap.getWidth(); 
   int tmp_height = bitmap.getHeight(); 
   matrix.postTranslate(-tmp_width / 2, -tmp_height / 2); //设置平移位置 
   matrix.postScale(m_scale, m_scale); //设置缩放比例 
   matrix.postTranslate(123 * m_scale, 146 * m_scale); 
  } 
 
  protected void onDraw(Canvas canvas) { 
   super.onDraw(canvas); 
   //给Canvas加上抗锯齿标志 
   canvas.setDrawFilter(mSetfil);//图片线条（通用）的抗锯齿 
   canvas.drawBitmap(m_bmp_disc, m_matrix_disc, mypaint); 
   canvas.drawBitmap(m_bmp_light, m_matrix_light, mypaint); 
  } 
 
  public void update() { 
   if (m_disc_rot_speed > 0.01 || m_state_play == 1){ 
    if (m_state_play == 1 && m_disc_rot_speed0.1){ 
     m_disc_rot_speed -= (m_disc_rot_speed)/40; 
    } 
    m_matrix_disc .postRotate(m_disc_rot_speed, 123*m_scale, 146*m_scale); 
    invalidate(); 
   } 
  } 
   
  public void onPause(){ 
   refreshHandle.stop(); 
  } 
  public void onResume(){ 
   refreshHandle.run(); 
  } 
   
 } 

package com.oyp.loadingdisk; 
 
import android.os.Handler; 
import android.os.Message; 
/** 
 * 用来发送消息和处理消息的 
 * @author ouyangpeng 
 * @link http://blog.csdn.net/ouyang_peng 
 */ 
public class RefreshHandle extends Handler { 
 LoadingDiscView loadingDiscView; 
 
 public RefreshHandle(LoadingDiscView loadingDiscView) { 
  this.loadingDiscView = loadingDiscView; 
  loadingDiscView.setRefreshHandle(this); 
 } 
 
 public void run() { 
  loadingDiscView.update(); 
  removeCallbacksAndMessages(null); 
  sendEmptyMessageDelayed(0, 65); 
 } 
 
 public void stop() { 
  removeCallbacksAndMessages(null); 
 } 
 
 @Override 
 public void handleMessage(Message msg) { 
  switch (msg.what) { 
  case 0: 
   run(); 
   break; 
  } 
 } 
} 

package com.oyp.loadingdisk; 
 
import android.app.Activity; 
import android.os.Bundle; 
import android.widget.RelativeLayout; 
/** 
 * @author ouyangpeng 
 * @link http://blog.csdn.net/ouyang_peng 
 */ 
public class LoadingActivity extends Activity { 
 private RelativeLayout motionView; 
 private LoadingDiscView disc_motion; 
 private RefreshHandle refreshHandle; 
 
 @Override 
 protected void onCreate(Bundle savedInstanceState) { 
  super.onCreate(savedInstanceState); 
  setContentView(R.layout.loading); 
  disc_motion = new LoadingDiscView(this); 
  refreshHandle = new RefreshHandle(disc_motion); 
  motionView = (RelativeLayout) findViewById(R.id.loading_disc); 
  motionView.addView(disc_motion); 
  refreshHandle.sendEmptyMessage(0); 
 } 
 @Override 
 protected void onResume() { 
  super.onResume(); 
  disc_motion.onResume(); 
 } 
}