I have a multiple array of buttons called button. Each one is tagged. How do I change the image on the button based on its tag and tag only. As of right now, it only changes the very last button.
-(void)buttonTapped:(id)sender{
NSLog (@"%i",[sender tag])];
[button setImage:[UIImage imageNamed:@"button_change.png"] forState:UIControlStateNormal];
}
Either:
for (UIButton *btn in button) {
if(btn.tag == 1)
{
// do something
break; // don't need to run the rest of the loop
}
}
if you want to use the array (it shouldn't be called 'button', use something with a plural for an array)
or an easier way:
UIButton *btn = (UIButton *)[self.view viewWithTag:1];
However a much simpler way would be to use the param in the callback (unless thats not the button you want). Like so:
-(void)buttonTapped:(id)sender
{
UIButton *tappedBtn = (UIButton *)sender;
[tappedBtn setImage:[UIImage imageNamed:@"button_change.png"] forState:UIControlStateNormal];
}
If you just want to change the button that was tapped the following should work.
-(void)buttonTapped:(id)sender
{
NSLog (@"%i",[sender tag])];
UIButton *tappedButton = (UIButton *)sender;
[tappedButton setImage:[UIImage imageNamed:@"button_change.png"] forState:UIControlStateNormal];
}
If you want to change other buttons then you can retrieve the buttons using
[self.view viewWithTag:1000]; //1000 is the tag you assigned
You don't really need to use tags in the this case. When an IBAction is invoked, the sender parameter is a pointer to the control that triggered the IBAction. (Your button.)
Thus, you already have a pointer to the button.
So, as others have pointed out, your code could read like this:
-(void)buttonTapped:(UIButton *)sender
{
[sender setImage:[UIImage imageNamed:@"button_change.png"] forState:UIControlStateNormal];
}
Note that I changed the type of sender to UIButton so that you don't have to cast it. As long as the action is only ever connected to a button, this is safe to do and makes the code cleaner.
As the other poster pointed out, having an array of buttons called "button" is bad. I renamed it to "buttons" in the code below:
If you wanted to do it using tags and an array of buttons, you could use code like this:
-(void)buttonTapped:(UIButton *)sender
{
NSUInteger tag = [sender tag];
UIButton *aButton = buttons[tag];
[aButton setImage:[UIImage imageNamed:@"button_change.png"] forState:UIControlStateNormal];
}
Create images with names button_change1.png
, button_change2.png
, etc.
And:
-(void) buttonTapped:(UIButton*)sender
{
NSString* imageName = [NSString stringWithFormat: @"button_change%ld.png", (long)sender.tag];
[button setImage:[UIImage imageNamed:imageName] forState:UIControlStateNormal];
}
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.