IOS Set button fillet (4 corners are free to set)

To set the 4 corners of a button:
Top left: Uirectcornertopleft
Lower left: Uirectcornerbottomleft
Top right: Uirectcornertopright
Bottom right: uirectcornerbottomright

Example code:

UIButton *button = [[UIButton alloc] Initwithframe:cgrectmake (50, 60, 80, 40)];
Button.backgroundcolor = [Uicolor Orangecolor];
[Self.view Addsubview:button];

This is set to the upper left and lower left corner.
Uibezierpath *maskpath = [Uibezierpath bezierPathWithRoundedRect:button.bounds byroundingcorners:    Uirectcornerbottomleft | Uirectcornertopleft Cornerradii:cgsizemake (8, 8)];
Cashapelayer *masklayer = [[Cashapelayer alloc] init];
Masklayer.frame = Button.bounds;
Masklayer.path = Maskpath.cgpath;
Button.layer.mask = Masklayer;

Effect Chart: