How to locate which programmatically created button is clicked?

Question

Hi,

I am doing an application on a Multiple Choice Question (MCQ) where I have to get questions, answers from a webservice. I have 1 question with 4 options, among the 4 options, I have 1 correct answer. Each of the options, I created a button programmatically. This is how I did it:

    UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    button.frame = CGRectMake(40, yButton, 30, 30);
    [button setTitle:@" " forState:UIControlStateNormal];

[button addTarget:self action:@selector(correctPressed)
 forControlEvents:UIControlEventTouchDown];
   [buttonArray addObject:button];

How many options I have in a questions will determine how many buttons will be created. Now when I want to show an indication that when a certain button is clicked, that button needs to stay highlighted until I decides to change my answer. I have done a few approaches.

I used IndexPath, hoping I could use indexPath.row like in TableView. It didnt work out at all. Can anyone help?

Thanks

Answer 1

Change this to

[button addTarget:self action:@selector(correctPressed)
 forControlEvents:UIControlEventTouchDown];
   [buttonArray addObject:button];

[button addTarget:self action:@selector(correctPressed:)
 forControlEvents:UIControlEventTouchDown];
   [buttonArray addObject:button];

now in your selector you will get a reference to the button.

eg.

UIButton * lastButtonPressed = nil;
-(void) correctPressed:(UIButton *) theButton{
   [theButton setHighlighted:YES];
   if(lastButtonPressed) [lastButtonPressed setHighlighted:NO];
   lastButtonPressed =  theButton;

}

** You may want to use the selected Method for buttons. So you can set a button selected instead.

I just typed this code, check my @selector change and that setHighlighted is actually correct but you should get the idea.

Now your code will call the selector and it should have a reference to the calling button.

John.

Answer 2

Its alright, I solved this issue.

What I did was did a button.tag = number; number++ somewhere in the codes. By using tagging methods, I then can keep track in the arrays which button is clicked.

-(void)correctAnswer
{
   yButton += 50;
   yLabel += 50;

   label = [[UILabel alloc] initWithFrame:CGRectMake(75, yLabel, 150, 30)];
   label.backgroundColor = [UIColor clearColor];
   [label setText:Option];
   [labelArray addObject:label];
   [self addSubview:label];

   button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
   button.frame = CGRectMake(40, yButton, 30, 30);
   button.tag = idx;
   NSLog(@"-------====== Tag Index is: %i", idx);
   UIImage * btnImage1 = [UIImage imageNamed:@"uncheckedCheckbox.png"];
   [button setImage:btnImage1 forState:UIControlStateNormal];
   [button addTarget:self action:@selector(correctPressed:)
    forControlEvents:UIControlEventTouchUpInside];

   [buttonArray addObject:button];
idx++;
[self addSubview:button];

}


-(void)correctPressed:(id)sender {

int but =  (int)[(UIButton*)sender tag];

if(correctValue) {
    UIImage * btnImage1 = [UIImage imageNamed:@"uncheckedCheckbox.png"];
    UIButton *btn1 = [buttonArray objectAtIndex:but];
    [btn1 setImage:btnImage1 forState:UIControlStateNormal];
    [btn1 setImage:btnImage1 forState:UIControlStateNormal];
    [btn1 setTitle:@"" forState:UIControlStateNormal];
    correctValue = NO;

} else {
    UIImage * btnImage2 = [UIImage imageNamed:@"checkedCheckbox.png"];
    UIButton *btn2 = [buttonArray objectAtIndex:but];
    [btn2 setImage:btnImage2 forState:UIControlStateNormal];
    [btn2 setImage:btnImage2 forState:UIControlStateNormal];
    [btn2 setTitle:@"" forState:UIControlStateNormal];
    correctValue = YES;
} 

NSLog(@"Correct answer!!");    
}

Answer 3

for(int i=0; i<[videolistArray count];i++){


    NSArray *myWords = [[[videolistArray objectAtIndex:i] valueForKey:@"video"] componentsSeparatedByCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@"/"]];
    //NSLog(@"%@",[myWords lastObject]);

    UIButton *guitaristButton = [[UIButton alloc]init];
    guitaristButton.frame = CGRectMake(0, ycomp, 300, 35);
    guitaristButton.tag = i;
    [guitaristButton setBackgroundImage:[UIImage imageNamed:@"green-buttons.png"] forState:UIControlStateNormal];
    [guitaristButton setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
    [guitaristButton setTitle:[myWords lastObject] forState:UIControlStateNormal];
    [guitaristButton addTarget:self action:@selector(VideoButtonSelected:) forControlEvents:UIControlEventTouchUpInside];
    //[guitaristButton performSelector:<#(SEL)aSelector#> withObject:<#(id)object1#> withObject:<#(id)object2#>
    [videoScrollView addSubview:guitaristButton];
    [guitaristButton release];

    ycomp = ycomp+35;   
}
videoScrollView.contentSize=CGSizeMake(300, ycomp);

} -(void)VideoButtonSelected:(UIButton*)sender{ NSArray *myWords = [[[videolistArray objectAtIndex:sender.tag] valueForKey:@"video"] componentsSeparatedByCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@"/"]]; //NSLog(@"%@",[myWords lastObject]); [setAlarmVedioButton setTitle:[myWords lastObject] forState:UIControlStateNormal]; [videoNameButtonView removeFromSuperview]; vedioString=[[videolistArray objectAtIndex:sender.tag] valueForKey:@"video"] ; }

in above code me make uibutton with help of array count and when i select any button then it display the same text value of array on last button