用于特殊文本编辑的对象

NSTextView

@interface MyTextView : NSTextView
{
    id target;
    SEL action;
}
@property (nonatomic, assign) id target;
@property (nonatomic, assign) SEL action;
@end

@implementation MyTextView

@synthesize target;
@synthesize action;

- (void)keyDown:(NSEvent *)theEvent
{
    if ([theEvent keyCode] == 36) // enter key
    {
        NSUInteger modifiers = [theEvent modifierFlags];
        if ((modifiers & NSShiftKeyMask) || (modifiers & NSAlternateKeyMask))
        {
            // shift or option/alt held: new line
            [super insertNewline:self];
        }
        else
        {
            // straight enter key: perform action
            [target performSelector:action withObject:self];
        }
    }
    else
    {
        // allow NSTextView to handle everything else
        [super keyDown:theEvent];
    }
}

@end

[myTextView setTarget:someController];
[mytextView setAction:@selector(omgTheUserPressedEnter:)];

insertNewline:

NSResponder

NSEvent