Lost in NSButton types and alternate images

问题

I’d like to have an NSButton with an image and an alternate image. The alternate image should be displayed while the button is being pressed and I’d also like to display the alternate image from code, calling something like [button setSelected:YES]. Is this possible without monkeing with the alternateImage property by hand?

回答1:

This is possible without manually changing the button's image:

In Interface Builder (xib/nib Editor) set the Type of NSButton to "Toggle" and the image will automatically change to the alternate image/title.

回答2:

You can use a NSButton with type set to NSToggleButton and then switch between the image and the alternateImage using the NSOnState / NSOffState states of the NSButton.

NSButton* theButton = [[NSButton alloc] initWithFrame:....];
theButton.image = .....
theButton.alternateImage = .....
theButton.state = NSOffState; // displays the image
theButton.state = NSOnState; // displays the alternateImage

回答3:

The easiest way is to switch between the two images:

@implementation NSButton (Select)

- (void) setSelected: (BOOL) yn
{
    NSImage *const tmp = [self image];
    [self setImage:[self alternateImage]];
    [self setAlternateImage:tmp];
}

@end

来源：https://stackoverflow.com/questions/5326337/lost-in-nsbutton-types-and-alternate-images