1、设置视图指定位置圆角
UIBezierPath *maskPath =[UIBezierPath bezierPathWithRoundedRect:_editButton.bounds byRoundingCorners:UIRectCornerBottomLeft | UIRectCornerBottomRight cornerRadii:CGSizeMake(60,60)];
CAShapeLayer *maskLayer = [[CAShapeLayer alloc] init];
maskLayer.frame = _editButton.bounds;
maskLayer.path = maskPath.CGPath;
_editButton.layer.mask = maskLayer;
CAShapeLayer *maskLayer = [[CAShapeLayer alloc] init];
maskLayer.frame = _editButton.bounds;
maskLayer.path = maskPath.CGPath;
_editButton.layer.mask = maskLayer;