圆形ImageView

/**
* 圆形ImageView
*/
public class CircleImageView extends ImageView {

private Paint paint;
private Paint paint2;

private int width;
private int height;

private int angleSize;

private SoftReference<Bitmap> sr;

public CircleImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init(context);
}

public CircleImageView(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
}

public CircleImageView(Context context) {
super(context);
init(context);
}

private void init(Context context) {
paint = new Paint(Paint.ANTI_ALIAS_FLAG);
paint.setColor(Color.WHITE);
paint.setAntiAlias(true);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));

paint2 = new Paint(Paint.ANTI_ALIAS_FLAG);
paint2.setXfermode(null);

}

@Override
public void draw(Canvas canvas) {

Bitmap bmpCache = null;
if (sr != null) {
bmpCache = sr.get();
}

if (bmpCache == null || bmpCache.isRecycled()
|| bmpCache.getWidth() != width
|| bmpCache.getHeight() != height) {
if (bmpCache != null) {
bmpCache.recycle();
}
bmpCache = Bitmap.createBitmap(width, height,
Bitmap.Config.ARGB_8888);
sr = new SoftReference<Bitmap>(bmpCache);
} else {
bmpCache.eraseColor(0);
}

Canvas canvas2 = new Canvas(bmpCache);
super.draw(canvas2);
drawLiftUp(canvas2);
drawRightUp(canvas2);
drawLiftDown(canvas2);
drawRightDown(canvas2);
canvas.drawBitmap(bmpCache, 0, 0, paint2);

}

private void drawLiftUp(Canvas canvas) {
Path path = new Path();
path.moveTo(0, angleSize);
path.lineTo(0, 0);
path.lineTo(angleSize, 0);
path.arcTo(new RectF(0, 0, angleSize * 2, angleSize * 2), -90, -90);
path.close();
canvas.drawPath(path, paint);
}

private void drawLiftDown(Canvas canvas) {
Path path = new Path();
path.moveTo(0, height - angleSize);
path.lineTo(0, height);
path.lineTo(angleSize, height);
path.arcTo(new RectF(0, height - angleSize * 2, 0 + angleSize * 2,
getHeight()), 90, 90);
path.close();
canvas.drawPath(path, paint);
}

private void drawRightDown(Canvas canvas) {
Path path = new Path();
path.moveTo(width - angleSize, height);
path.lineTo(width, height);
path.lineTo(width, height - angleSize);
path.arcTo(new RectF(width - angleSize * 2, height - angleSize * 2,
width, height), 0, 90);
path.close();
canvas.drawPath(path, paint);
}

private void drawRightUp(Canvas canvas) {
Path path = new Path();
path.moveTo(width, angleSize);
path.lineTo(width, 0);
path.lineTo(width - angleSize, 0);
path.arcTo(
new RectF(width - angleSize * 2, 0, width, 0 + angleSize * 2),
-90, 90);
path.close();
canvas.drawPath(path, paint);
}

@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
width = w;
height = h;
angleSize = ((width <= height) ? width : height) / 2;
}

}