In Objective C
// Create the path (with only the top-left corner rounded)
UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:imageView.bounds
byRoundingCorners:UIRectCornerTopLeft| UIRectCornerTopRight
cornerRadii:CGSizeMake(10.0, 10.0)];
// Create the shape layer and set its path
CAShapeLayer *maskLayer = [CAShapeLayer layer];
maskLayer.frame = imageView.bounds;
maskLayer.path = maskPath.CGPath;
// Set the newly created shape layer as the mask for the image view's layer
imageView.layer.mask = maskLayer;
This is other to use top rounded corner.
Round two corners in UIView
In Swift !!!
myView.clipsToBounds = true
myView.layer.cornerRadius = 10
myView.layer.maskedCorners = [.layerMinXMinYCorner,.layerMaxXMinYCorner]