Android应用框架搭建------工具类（图像的处理)

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;
    }
    
}