android实现图片圆角代码

圆角效果：

 

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
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;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.widget.ImageView;

public class Main extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
      
        setContentView(R.layout.main);   
        Drawable drawable = getResources().getDrawable(R.drawable.jpg1);
        BitmapDrawable bitmapDrawable = (BitmapDrawable)drawable;
        Bitmap bitmap = bitmapDrawable.getBitmap();    
       
         ImageView imageView = (ImageView)findViewById(R.id.imgShow);
         imageView.setImageBitmap(Main.getRoundedCornerBitmap(bitmap));        
        
    }
 // 将图片的四角圆化
    public static Bitmap getRoundedCornerBitmap(Bitmap bitmap) { 
     
        Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),  
            bitmap.getHeight(), Config.ARGB_8888);
        //得到画布
        Canvas canvas = new Canvas(output); 
     
        
       //将画布的四角圆化
        final int color = Color.RED;  
        final Paint paint = new Paint();  
        //得到与图像相同大小的区域  由构造的四个值决定区域的位置以及大小
        final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());  
        final RectF rectF = new RectF(rect);  
        //值越大角度越明显
        final float roundPx = 50;  
       
        paint.setAntiAlias(true);  
        canvas.drawARGB(0, 0, 0, 0);  
        paint.setColor(color);  
        //drawRoundRect的第2,3个参数一样则画的是正圆的一角，如果数值不同则是椭圆的一角
        canvas.drawRoundRect(rectF, roundPx,roundPx, paint);  
       
        paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));  
        canvas.drawBitmap(bitmap, rect, rect, paint);  
       
        return output;  
      } 
    
}