Android程序设计-圆形图片的实现

<com.makeramen.roundedimageview.RoundedImageView
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:id="@+id/imageView1"
        android:layout_width="40dp"
        android:layout_height="40dp"
        android:src="@drawable/photo"
        app:riv_corner_radius="30dip"
        app:riv_border_width="2dip"
        app:riv_border_color="#333333"
        app:riv_mutate_background="true"
        app:riv_oval="true" />

public static class RoundedDrawable extends Drawable {

        protected final float cornerRadius;
        protected final int margin;

        protected final RectF mRect = new RectF(),
                mBitmapRect;
        protected final BitmapShader bitmapShader;
        protected final Paint paint;

        public RoundedDrawable(Bitmap bitmap, int cornerRadius, int margin) {
            this.cornerRadius = cornerRadius;
            this.margin = margin;

            bitmapShader = new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
            mBitmapRect = new RectF (margin, margin, bitmap.getWidth() - margin, bitmap.getHeight() - margin);
            
            paint = new Paint();
            paint.setAntiAlias(true);
            paint.setShader(bitmapShader);
        }

        @Override
        protected void onBoundsChange(Rect bounds) {
            super.onBoundsChange(bounds);
            mRect.set(margin, margin, bounds.width() - margin, bounds.height() - margin);
            
            // Resize the original bitmap to fit the new bound
            Matrix shaderMatrix = new Matrix();
            shaderMatrix.setRectToRect(mBitmapRect, mRect, Matrix.ScaleToFit.FILL);
            bitmapShader.setLocalMatrix(shaderMatrix);
            
        }

        @Override
        public void draw(Canvas canvas) {
            canvas.drawRoundRect(mRect, cornerRadius, cornerRadius, paint);
        }

        @Override
        public int getOpacity() {
            return PixelFormat.TRANSLUCENT;
        }

        @Override
        public void setAlpha(int alpha) {
            paint.setAlpha(alpha);
        }

        @Override
        public void setColorFilter(ColorFilter cf) {
            paint.setColorFilter(cf);
        }
    }



imageAware.setImageDrawable(new RoundedDrawable(bitmap, cornerRadius, margin));