android 指定组件的圆角图片处理

红色框内的图片是服务器上获取到的，本身是矩形，要怎么做成仅左下方和右下方是圆角的效果呢？

下面提供了一种简单的方式

package com.lurencun.androidsysteminfomation;

 

import android.graphics.Bitmap;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.graphics.PorterDuffXfermode;

import android.graphics.Rect;

import android.graphics.RectF;

import android.graphics.Bitmap.Config;

import android.graphics.PorterDuff.Mode;

 

/**
 * <pre>
 * 功能说明： android 指定组件的圆角图片处理
 * 日期： 2015年1月7日
 * 开发者： 左丶郁
 * 
 * 历史记录
 *    修改内容：
 *    修改人员：
 *    修改日期： 2015年1月7日
 * </pre>
 */

public class BitmapFillet {

 

    public static final int ALL = 347120;

    public static final int TOP = 547120;

    public static final int LEFT = 647120;

    public static final int RIGHT = 747120;

    public static final int BOTTOM = 847120;

     

    /**

     *

     * 指定图片的切边，对图片进行圆角处理

     * @param type 具体参见：{@link BitmapFillet.ALL} , {@link BitmapFillet.TOP} ,

     *              {@link BitmapFillet.LEFT} , {@link BitmapFillet.RIGHT} , {@link BitmapFillet.BOTTOM}

     * @param bitmap 需要被切圆角的图片

     * @param roundPx 要切的像素大小

     * @return

     *

     */

    public static Bitmap fillet(int type,Bitmap bitmap,int roundPx) {

        try {

            // 其原理就是：先建立一个与图片大小相同的透明的Bitmap画板

            // 然后在画板上画出一个想要的形状的区域。

            // 最后把源图片帖上。

            final int width = bitmap.getWidth();

            final int height = bitmap.getHeight();

             

            Bitmap paintingBoard = Bitmap.createBitmap(width,height, Config.ARGB_8888);

            Canvas canvas = new Canvas(paintingBoard);

            canvas.drawARGB(Color.TRANSPARENT, Color.TRANSPARENT, Color.TRANSPARENT, Color.TRANSPARENT);

             

            final Paint paint = new Paint();

            paint.setAntiAlias(true);

            paint.setColor(Color.BLACK);  

             

            if( TOP == type ){

                clipTop(canvas,paint,roundPx,width,height);

            }else if( LEFT == type ){

                 clipLeft(canvas,paint,roundPx,width,height);

            }else if( RIGHT == type ){

                clipRight(canvas,paint,roundPx,width,height);

            }else if( BOTTOM == type ){

                clipBottom(canvas,paint,roundPx,width,height);

            }else{

                clipAll(canvas,paint,roundPx,width,height);

            }

             

            paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));

            //帖子图

            final Rect src = new Rect(0, 0, width, height);

            final Rect dst = src;

            canvas.drawBitmap(bitmap, src, dst, paint);  

            return paintingBoard;

        } catch (Exception exp) {       

            return bitmap;

        }

    }

     

    private static void clipLeft(final Canvas canvas,final Paint paint,int offset,int width,int height){

        final Rect block = new Rect(offset,0,width,height);

        canvas.drawRect(block, paint);

        final RectF rectF = new RectF(0, 0, offset * 2 , height);

        canvas.drawRoundRect(rectF, offset, offset, paint);

    }

     

    private static void clipRight(final Canvas canvas,final Paint paint,int offset,int width,int height){

        final Rect block = new Rect(0, 0, width-offset, height);

        canvas.drawRect(block, paint);

        final RectF rectF = new RectF(width - offset * 2, 0, width , height);

        canvas.drawRoundRect(rectF, offset, offset, paint);

    }

     

    private static void clipTop(final Canvas canvas,final Paint paint,int offset,int width,int height){

        final Rect block = new Rect(0, offset, width, height);

        canvas.drawRect(block, paint);

        final RectF rectF = new RectF(0, 0, width , offset * 2);

        canvas.drawRoundRect(rectF, offset, offset, paint);

    }

     

    private static void clipBottom(final Canvas canvas,final Paint paint,int offset,int width,int height){

        final Rect block = new Rect(0, 0, width, height - offset);

        canvas.drawRect(block, paint);

        final RectF rectF = new RectF(0, height - offset * 2 , width , height);

        canvas.drawRoundRect(rectF, offset, offset, paint);

    }

     

    private static void clipAll(final Canvas canvas,final Paint paint,int offset,int width,int height){

        final RectF rectF = new RectF(0, 0, width , height);

        canvas.drawRoundRect(rectF, offset, offset, paint);

    }

}

效果图如下：