Android 圆角图形和圆角头像的完美实现

/**
* 圆角图片控件
*/
public class RoundImageView extends ImageView {

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

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

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

private final RectF roundRect = new RectF();
private float rect_adius = 10;
private final Paint maskPaint = new Paint();
private final Paint zonePaint = new Paint();
private void init() {
maskPaint.setAntiAlias(true);
maskPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
//
zonePaint.setAntiAlias(true);
zonePaint.setColor(Color.WHITE);
//
float density = getResources().getDisplayMetrics().density;
rect_adius = rect_adius * density;
}

public void setRectAdius(float adius) {
rect_adius = adius;
invalidate();
}

@Override
protected void onLayout(boolean changed, int left, int top, int right,
int bottom) {
super.onLayout(changed, left, top, right, bottom);
int w = getWidth();
int h = getHeight();
roundRect.set(0, 0, w, h);
}

@Override
public void draw(Canvas canvas) {
try {
canvas.saveLayer(roundRect, zonePaint, Canvas.ALL_SAVE_FLAG);
canvas.drawRoundRect(roundRect, rect_adius, rect_adius, zonePaint);
//
canvas.saveLayer(roundRect, maskPaint, Canvas.ALL_SAVE_FLAG);
super.draw(canvas);
canvas.restore();
} catch (Exception e) {
e.printStackTrace();
}
}

}