如何确定从三个按钮中按下了哪个按钮

Question

I have three buttons, they all do the same thing perform a segue. All linked to the same connection.

- (IBAction)difficultyButtonPressed:(id)sender {
    // Any difficulty selected
    [self performSegueWithIdentifier:@"mainGameTurnGuess" sender:self];
}

What I need to do is determine what button was pressed in the prepareForSegue method. How can I tell which out of the three buttons are pressed.

Without looking at the wording/text on the button as this would change for localisation.

Answer 1

You can ditermine the Taped Button using Tag Value suppose you have tree Button for Example:-

@property (nonatomic, strong)  UIButton *btn1;
@property (nonatomic, strong) UIButton *btn2;
@property (nonatomic, strong) UIButton *btn3;

Then set Tag of Button like:-

btn1.tag=1;
btn2.tag=2;
btn3.tag=3;

and set Same IBAction for each Button and:-

[btn1 addTarget:self action:@selector(difficultyButtonPressed:) forControlEvents:UIControlEventTouchUpInside];

[btn2 addTarget:self action:@selector(difficultyButtonPressed:) forControlEvents:UIControlEventTouchUpInside];

[btn3 addTarget:self action:@selector(difficultyButtonPressed:) forControlEvents:UIControlEventTouchUpInside];

- (IBAction)difficultyButtonPressed:(UIButton*)sender
{
 NSLog(@"Button tag is %d",sender.tag);

     // you can use if else condition using sender.tag  like

      if(sender.tag==1)//first button related identifire
      {
           [self performSegueWithIdentifier:@"mainGameTurnGuess_FirstButtonIdentirier" sender:sender]; 
      }
      else if(sender.tag==2)//second button related identifier
      {
            [self performSegueWithIdentifier:@"mainGameTurnGuess_secondButtonIdentirier" sender:sender]; 
      }
      else   //Third button related identifier
      {
            [self performSegueWithIdentifier:@"mainGameTurnGuess_ThirdButtonIdentirier" sender:sender]; 
      }

}

For Info

If you are using id in IBAction then you get the Button Object like:-

- (IBAction)difficultyButtonPressed:(id)sender {
    UIButton *button = (UIButton *)sender;
    NSLog(@"Button tag is %d",button.tag);
}

Answer 2

将按钮的标记存储在实例变量中，并在调用prepareForSegue时查看该变量

Answer 3

You can forward on the sender parameter sent to difficultyButtonPressed: as that is the button that was pressed. That is, if you do this:

- (IBAction)difficultyButtonPressed:(id)sender {
    // Any difficulty selected
    [self performSegueWithIdentifier:@"mainGameTurnGuess" sender:sender];
}

the sender parameter sent to prepareForSegue:sender: will be the button that was pressed.

Answer 4

You can also use the buttons Restoration Id. In prepareForSegue you can then do the following:

UIButton *btnSender;
if ([sender isMemberOfClass:[UIButton class]])
{
    btnSender = (UIButton *)sender;
}

// Then you can reference the Restoration Id or a tag of the clicked button to do further conditional logic if you want.
if([btnSender.restorationIdentifier isEqualToString:@"myBtn1"])
{
   //do something
}

I quote the apple documentation:

Because segues can be triggered from multiple sources, you can use the information in the segue and sender parameters to disambiguate between different logical paths in your app. For example, if the segue originated from a table view, the sender parameter would identify the table view cell that the user tapped. You could use that information to set the data on the destination view controller