NSView - setCornerRadius curve all 4 corners

Question

I am working on a Mac app and need a custom NSView with 4 rounded corners. Everything I have tried either produces no results, or only curves the botton two edges of the NSView. Is there a way to curve all 4 corners of an NSView?

I tried making a custom class and used the initWithFrame method which produces no results what so ever. I then tried the drawRect method which curves the bottom two corners only:

-(void)drawRect:(NSRect)dirtyRect {
    [super drawRect:dirtyRect];
    
    [self setWantsLayer:YES];
    [self.layer setFrame:self.frame];
    [self.layer setMasksToBounds:YES];
    [self.layer setCornerRadius:10.0f];
}

How can I curve all four corners? And does anyone know why developing for the Mac is so much harder than on iOS. Why does even the most basic task always require a custom class (i.e.: setting the NSView background colour or running the equivalent of a UIViewAnimation....).

Answer 1

This three lines give me rounded corners and red background for the testView of type NSView linked as an outlet from storyboard in viewDidLoad of a ViewController, no subclassing needed:

_testView.wantsLayer = YES;
_testView.layer.backgroundColor = [NSColor redColor].CGColor;
_testView.layer.cornerRadius = 10.;

Edit

Not all corners were rounded because of this line:

[self.layer setFrame:self.frame];

Basically you don't need it, you set proper layer frame with this line:

[self setWantsLayer:YES];

If you do want to set layer frame explicitely, you want to use

[self.layer setFrame:self.bounds];

Read about difference between frame and bounds. And aforementioned code works in drawRect: too.