Which delegate method should I use to respond to clicks on an NSTextField?

问题

I am trying to respond to a click within a textfield. When the click occurs, I am going to open a panel. My initial thought was to use a delegate method to respond to the click event - but I found that:

This method doesn't work:

(void)textDidBeginEditing:(NSNotification *)aNotification

This method does work, but only when I actually edit the text within the text field, not when I first click it. And - if I edit the text a second time, this method stops working:

(void)controlTextDidBeginEditing:(NSNotification *)aNotification

I could use as much detail as possible - or a code example, ideally. I know that an nstextfield inherits from NSControl, which has a mouseDown event. Is there a similar way to respond to the event with a textfield, also?

回答1:

Since NSTextField inherits from the NSControl class, it also inherits the -(void)mouseDown:(NSEvent*) theEvent method.

回答2:

I needed to have an NSTextField call a delegate function upon clicking it today, and thought this basic code might be useful. Note that NSTextField already has a delegate and that in SDK v10.6, the delegate already has a protocol associated with it. Note that if you don't care about protocols, compiler warnings, etc., you don't need the protocol and property declarations or the getter and setter.

MouseDownTextField.h:

#import <Appkit/Appkit.h>
@class MouseDownTextField;

@protocol MouseDownTextFieldDelegate <NSTextFieldDelegate>
-(void) mouseDownTextFieldClicked:(MouseDownTextField *)textField;
@end

@interface MouseDownTextField: NSTextField {
}
@property(assign) id<MouseDownTextFieldDelegate> delegate;
@end

MouseDownTextField.m:
#import "MouseDownTextField.h"

@implementation MouseDownTextField
-(void)mouseDown:(NSEvent *)event {
  [self.delegate mouseDownTextFieldClicked:self];
}

-(void)setDelegate:(id<MouseDownTextFieldDelegate>)delegate {
  [super setDelegate:delegate];
}

-(id)delegate {
  return [super delegate];
}

AppDelegate.h:
@interface AppDelegate <MouseDownTextFieldDelegate>
...
@property IBOutlet MouseDownTextField *textField;
...

AppDelegate.m:
...
  self.textField.delegate = self;
...
-(void)mouseDownTextFieldClicked:(MouseDownTextField *)textField {
  NSLog(@"Clicked");
  ...
}
...

If you're building with 10.5 SDK, don't have the protocol inherit from NSTextFieldDelegate.

来源：https://stackoverflow.com/questions/684166/which-delegate-method-should-i-use-to-respond-to-clicks-on-an-nstextfield

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cocoa

macos

nstextfield