Android中几种图片特效的处理的实现方法

package com.android.tutor; 
import android.graphics.Bitmap; 
import android.graphics.Canvas; 
import android.graphics.LinearGradient; 
import android.graphics.Matrix; 
import android.graphics.Paint; 
import android.graphics.PixelFormat; 
import android.graphics.PorterDuffXfermode; 
import android.graphics.Rect; 
import android.graphics.RectF; 
import android.graphics.Bitmap.Config; 
import android.graphics.PorterDuff.Mode; 
import android.graphics.Shader.TileMode; 
import android.graphics.drawable.Drawable; 
public class ImageUtil { 
   
  //放大缩小图片 
  public static Bitmap zoomBitmap(Bitmap bitmap,int w,int h){ 
    int width = bitmap.getWidth(); 
    int height = bitmap.getHeight(); 
    Matrix matrix = new Matrix(); 
    float scaleWidht = ((float)w / width); 
    float scaleHeight = ((float)h / height); 
    matrix.postScale(scaleWidht, scaleHeight); 
    Bitmap newbmp = Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, true); 
    return newbmp; 
  } 
  //将Drawable转化为Bitmap 
   public static Bitmap drawableToBitmap(Drawable drawable){ 
      int width = drawable.getIntrinsicWidth(); 
      int height = drawable.getIntrinsicHeight(); 
      Bitmap bitmap = Bitmap.createBitmap(width, height, 
          drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888 
              : Bitmap.Config.RGB_565); 
      Canvas canvas = new Canvas(bitmap); 
      drawable.setBounds(0,0,width,height); 
      drawable.draw(canvas); 
      return bitmap; 
       
    } 
    
   //获得圆角图片的方法 
  public static Bitmap getRoundedCornerBitmap(Bitmap bitmap,float roundPx){ 
     
    Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap 
        .getHeight(), Config.ARGB_8888); 
    Canvas canvas = new Canvas(output); 
  
    final int color = 0xff424242; 
    final Paint paint = new Paint(); 
    final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight()); 
    final RectF rectF = new RectF(rect); 
  
    paint.setAntiAlias(true); 
    canvas.drawARGB(0, 0, 0, 0); 
    paint.setColor(color); 
    canvas.drawRoundRect(rectF, roundPx, roundPx, paint); 
  
    paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN)); 
    canvas.drawBitmap(bitmap, rect, rect, paint); 
  
    return output; 
  } 
  //获得带倒影的图片方法 
  public static Bitmap createReflectionImageWithOrigin(Bitmap bitmap){ 
    final int reflectionGap = 4; 
    int width = bitmap.getWidth(); 
    int height = bitmap.getHeight(); 
     
    Matrix matrix = new Matrix(); 
    matrix.preScale(1, -1); 
     
    Bitmap reflectionImage = Bitmap.createBitmap(bitmap,  
        0, height/2, width, height/2, matrix, false); 
     
    Bitmap bitmapWithReflection = Bitmap.createBitmap(width, (height + height/2), Config.ARGB_8888); 
     
    Canvas canvas = new Canvas(bitmapWithReflection); 
    canvas.drawBitmap(bitmap, 0, 0, null); 
    Paint deafalutPaint = new Paint(); 
    canvas.drawRect(0, height,width,height + reflectionGap, 
        deafalutPaint); 
     
    canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null); 
     
    Paint paint = new Paint(); 
    LinearGradient shader = new LinearGradient(0, 
        bitmap.getHeight(), 0, bitmapWithReflection.getHeight() 
        + reflectionGap, 0x70ffffff, 0x00ffffff, TileMode.CLAMP); 
    paint.setShader(shader); 
    // Set the Transfer mode to be porter duff and destination in 
    paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN)); 
    // Draw a rectangle using the paint with our linear gradient 
    canvas.drawRect(0, height, width, bitmapWithReflection.getHeight() 
        + reflectionGap, paint); 
  
    return bitmapWithReflection; 
  } 
   
} 

<?xml version="1.0" encoding="utf-8"?> 
 
   
   
 

package com.android.tutor; 
import android.app.Activity; 
import android.graphics.Bitmap; 
import android.graphics.drawable.Drawable; 
import android.os.Bundle; 
import android.widget.ImageView; 
public class Imagedemo extends Activity { 
  private ImageView mImageView01,mImageView02; 
   
  public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main); 
    setupViews(); 
  } 
   
  private void setupViews(){ 
    mImageView01 = (ImageView)findViewById(R.id.image01); 
    mImageView02 = (ImageView)findViewById(R.id.image02); 
     
    //获取壁纸返回值是Drawable 
    Drawable drawable = getWallpaper(); 
    //将Drawable转化为Bitmap 
    Bitmap bitmap = ImageUtil.drawableToBitmap(drawable); 
    //缩放图片 
    Bitmap zoomBitmap = ImageUtil.zoomBitmap(bitmap, 100, 100); 
    //获取圆角图片 
    Bitmap roundBitmap = ImageUtil.getRoundedCornerBitmap(zoomBitmap, 10.0f); 
    //获取倒影图片 
    Bitmap reflectBitmap = ImageUtil.createReflectionImageWithOrigin(zoomBitmap); 
    //这里可以让Bitmap再转化为Drawable 
//   Drawable roundDrawable = new BitmapDrawable(roundBitmap);     
//   Drawable reflectDrawable = new BitmapDrawable(reflectBitmap);     
//   mImageView01.setBackgroundDrawable(roundDrawable); 
//   mImageView02.setBackgroundDrawable(reflectDrawable); 
         
    mImageView01.setImageBitmap(roundBitmap); 
    mImageView02.setImageBitmap(reflectBitmap); 
  } 
    
     
}