import android.app.Activity; 
import android.content.Context; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.graphics.Canvas; 
import android.graphics.Color; 
import android.graphics.Paint; 
import android.graphics.PorterDuff; 
import android.graphics.PorterDuff.Mode; 
import android.graphics.PorterDuffXfermode; 
import android.graphics.Rect; 
import android.graphics.RectF; 
import android.graphics.drawable.Drawable; 
import android.os.Bundle; 
import android.view.View; 

public class MyCanvasActivity extends Activity { 
 /** Called when the activity is first created. */ 
 @Override 
 public void onCreate(Bundle savedInstanceState) { 
  super.onCreate(savedInstanceState); 
  setContentView(new ImageEffect(this)); 
 } 

 class ImageEffect extends View{ 
  Paint paint; 
  public ImageEffect(Context context){ 
   super(context); 
   paint= new Paint(); //初始化畫(huà)筆，為后面陰影效果使用。  
   paint.setAntiAlias(true);//去除鋸齒。  
   paint.setShadowLayer(5f, 5.0f, 5.0f, Color.BLACK); //設(shè)置陰影層，這是關(guān)鍵。  
   paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN)); 

  } 
  public void onDraw(Canvas canvas){ 
   super.onDraw(canvas); 
   int posX = 20; 
   int posY = 50; 
   int PicWidth,PicHeight; 

  Drawable drawable = getResources().getDrawable(R.drawable.pic); 
  Drawable dbe = getResources().getDrawable(R.drawable.pic).mutate();//如果不調(diào)用mutate方法，則原圖也會(huì)被改變，因?yàn)檎{(diào)用的資源是同一個(gè)，所有對(duì)象是共享狀態(tài)的。  
  Drawable drawTest = getResources().getDrawable(R.drawable.pic); 
  Bitmap bmp = BitmapFactory.decodeResource(getResources(), R.drawable.pic); 
  PicWidth = drawable.getIntrinsicWidth(); 
  PicHeight = drawable.getIntrinsicHeight(); 

  drawTest.setBounds(posX, (2 * posY) + PicHeight, posX + PicWidth, (2 * posY) + 2 * PicHeight ); 
  drawable.setBounds(posX,posY,posX+PicWidth,posY+PicHeight); 
  dbe.setBounds(0, 0, PicWidth, PicHeight); 

  canvas.drawColor(Color.WHITE);//設(shè)置畫(huà)布顏色  
  canvas.save(Canvas.MATRIX_SAVE_FLAG); 
  dbe.setColorFilter(0x7f000000,PorterDuff.Mode.SRC_IN); 
  canvas.translate(posX + (int)(0.9 * PicWidth/2), posY + PicHeight/2);//圖像平移為了剛好在原圖后形成影子效果。  
  canvas.skew(-0.9F, 0.0F);//圖像傾斜效果。  
  canvas.scale(1.0f, 0.5f);//圖像（其實(shí)是畫(huà)布）縮放，Y方向縮小為1/2。  
  dbe.draw(canvas);//此處為畫(huà)原圖像影子效果圖，比原圖先畫(huà)，則會(huì)在下層。  
  drawable.clearColorFilter(); 
  canvas.restore(); 

  canvas.save(Canvas.MATRIX_SAVE_FLAG); 
  drawable.draw(canvas);//此處為畫(huà)原圖像，由于canvas有層次效果，因此會(huì)蓋在影子之上。  
  canvas.restore(); 

  //默認(rèn)無(wú)效果原圖  
  canvas.save(Canvas.MATRIX_SAVE_FLAG); 
  drawTest.draw(canvas); 
  canvas.restore(); 

  //圖片陰影效果  
  Rect rect = new Rect(2*posX + PicWidth + 3, 2*posY + PicHeight + 3, 2*posX + 2*PicWidth - 2, 2*posY + 2*PicHeight - 2); 
  //由于圖片的實(shí)際尺寸比顯示出來(lái)的圖像要大一些，因此需要適當(dāng)更改下大小，以達(dá)到較好的效果  

  RectF rectF = new RectF(rect); 
  canvas.drawRoundRect(rectF, 10f, 10f, paint);//在原有矩形基礎(chǔ)上，畫(huà)成圓角矩形，同時(shí)帶有陰影層。  
  canvas.drawBitmap(bmp, 2*posX + PicWidth, 2*posY + PicHeight, null);//畫(huà)上原圖。  
  canvas.restore(); 
  } 
 }