重写ImageView画圆



import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;

public class CustomImageView extends ImageView{

   public CustomImageView(Context context) {
      super(context);
      // TODO Auto-generated constructor stub
   }

   public CustomImageView(Context context, AttributeSet attrs, int defStyle) {
      super(context, attrs, defStyle);
      // TODO Auto-generated constructor stub
   }

   public CustomImageView(Context context, AttributeSet attrs) {
      super(context, attrs);
      // TODO Auto-generated constructor stub
   }
   
   @Override
    protected void onDraw(Canvas canvas) {
        Drawable drawable = getDrawable();
        if (drawable == null) {
            return;
        }

        if (getWidth() == 0 || getHeight() == 0) {
            return;
        }
        Bitmap b =  ((BitmapDrawable)drawable).getBitmap() ;
        Bitmap bitmap = b.copy(Config.ARGB_8888, true);

        Bitmap roundBitmap =  getCroppedBitmap(bitmap, getWidth());
        canvas.drawBitmap(roundBitmap, 0, 0, null);
    }

    public static Bitmap getCroppedBitmap(Bitmap bmp, int radius) {
        Bitmap sbmp;
        if(bmp.getWidth() != radius || bmp.getHeight() != radius)
            sbmp = Bitmap.createScaledBitmap(bmp, radius, radius, false);
        else
            sbmp = bmp;

        Bitmap output = Bitmap.createBitmap(sbmp.getWidth(), sbmp.getHeight(), Config.ARGB_8888);
        final Rect rect = new Rect(0, 0, sbmp.getWidth(), sbmp.getHeight());

        Paint paint = new Paint();
        paint.setAntiAlias(true);
        paint.setFilterBitmap(true);
        paint.setDither(true);
        paint.setColor(Color.parseColor("#BAB399"));

        Canvas c = new Canvas(output);
        c.drawARGB(0, 0, 0, 0);
        c.drawCircle(sbmp.getWidth() / 2+0.7f, sbmp.getHeight() / 2+0.7f, sbmp.getWidth() / 2+0.1f, paint);
        paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
        c.drawBitmap(sbmp, rect, rect, paint);

        return output;
    }
}