Can I have UIToolbar Bar Button Item States

Is there an开发者_如何学Python easy way to have an on state and an off state for the UIBarButtonItems, with different images for each?

Thanks

There isn't a built-in way, but I can think of a few approaches (depending on your needs):

• Bind the button to a method that toggles whatever the button is meant to toggle, and then changes the button's image property accordingly

• Create your own subclass of UIBarButtonItem that looks something like this:

  @interface ToggleBarButtonItem : UIBarButtonItem {
      BOOL _state;
      UIImage * onImage;
      UIImage * offImage;
  }
  - (BOOL)toggleState;
  @property (nonatomic, retain) UIImage * onImage;
  @property (nonatomic, retain) UIImage * offImage;
  @end
  
  @implementation ToggleBarButtonItem
  - (BOOL)toggleState {
      if (_state) {
          // Switch to Off state
          self.image = offImage;
      }
      else {
          // Switch to On state
          self.image = onImage;
      }
      return _state = !_state;
  }
  @end