how to change window color on mac os

Question

mac os: 10.10 xcode:6.1

I got a "default cocoa program" by Xcode. and I want to change the window color...after researching, I did the following code in AppDelegate.m:

NSWindow *myWindow;
NSColor *semiTransparentBlue =
[NSColor colorWithDeviceRed:0.0 green:0.0 blue:1.0 alpha:0.5];
[myWindow setBackgroundColor:semiTransparentBlue];

but window color not changed...

1: how to change the window color on mac os? 2: no NSWindow in "Default cocoa program" by Xcode, why will get a window?

thank your very much.

i tried some functions...but failed..following is the detail:

• (void)applicationDidFinishLaunching:(NSNotification *)aNotification { // Insert code here to initialize your application

  //compile success but the window's color is not changed. [[NSApplication sharedApplication] keyWindow].backgroundColor = [NSColor redColor];

  //or the following two got compiled error self.view.backgroundColor = [UIColor redColor]; self.window.backgroundColor = [UIColor redColor];

}

Answer 1

in your app delegate juste type this :

self.window.backgroundColor = [NSColor whiteColor];