android制作圆角图片和图片倒影

From:http://blog.csdn.net/mldxs/article/details/9179515

主要包含了 放大缩小 圆角图片 和 倒影 

 package com.lp.imageUI;

 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);
         /**
          * 画一个圆角矩形
          * rectF: 矩形
          * roundPx 圆角在x轴上或y轴上的半径
          */
         canvas.drawRoundRect(rectF, roundPx, roundPx+10, paint);
         //设置两张图片相交时的模式
         //setXfermode前的是 dst 之后的是src
         //在正常的情况下，在已有的图像上绘图将会在其上面添加一层新的形状。
         //如果新的Paint是完全不透明的，那么它将完全遮挡住下面的Paint；
         //PorterDuffXfermode就可以来解决这个问题
         //canvas原有的图片 可以理解为背景 就是dst
         //新画上去的图片 可以理解为前景 就是src
 //      paint.setXfermode(new PorterDuffXfermode(Mode.SRC_OUT));
         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){
         // 图片与倒影间隔距离
         final int reflectionGap = 4;
         // 图片的宽度
         int width = bitmap.getWidth();
          // 图片的高度
         int height = bitmap.getHeight();

         Matrix matrix = new Matrix();
         // 图片缩放，x轴变为原来的1倍，y轴为-1倍,实现图片的反转
         matrix.preScale(1, -1);
         // 创建反转后的图片Bitmap对象，图片高是原图的一半。
         Bitmap reflectionImage = Bitmap.createBitmap(bitmap,
                 0, height/2, width, height/2, matrix, false);
         // 创建标准的Bitmap对象，宽和原图一致，高是原图的1.5倍。 可以理解为这张图将会在屏幕上显示 是原图和倒影的合体
         Bitmap bitmapWithReflection = Bitmap.createBitmap(width, (height + height/2), Config.ARGB_8888);
          // 构造函数传入Bitmap对象，为了在图片上画图
         Canvas canvas = new Canvas(bitmapWithReflection);
         // 画原始图片
         canvas.drawBitmap(bitmap, 0, 0, null);
         // 画间隔矩形
         Paint deafalutPaint = new Paint();
         canvas.drawRect(0, height,width,height + reflectionGap,
                 deafalutPaint);
         // 画倒影图片
         canvas.drawBitmap(reflectionImage, 0, height + reflectionGap, null);
         // 实现倒影渐变效果
         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
         // 覆盖效果
         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;
     }

 }