NSTimer is Not stopping when double Click on a Button - objective-c

Question

I have NSTimer to display an image after 2 seconds when i click on button. It is working fine when I Click on a Button, But the problem is When I double Click the Button the NSTimer is Not Stopping. Continuously it is displaying images(calling NSTimer method) without Clicking on the button for Next Time. How to stop the NSTimer when i double Click / more Clicks on that button at a time.
*This is my Code*
-(void)buttonClicked
{
timer = [NSTimer scheduledTimerWithTimeInterval:0.2 target:self selector:#selector(timerClicked) userInfo:nil repeats:YES];
imgviewtransparent.image = [UIImage imageNamed:[imagesArray objectAtIndex:i]];
}
-(void)timerClicked
{
[timer invalidate];
timer = nil;
}

Answer 1

With double Click it will schedule timer twice.
You can create a BOOL property to avoid this if you want.
-(void)viewDidLoad{
[super viewDidLoad];
//Define all your implementation
//Set BOOL property to no at start
self.isButtonClicked = NO; // You need to define this BOOL property as well.
}
-(void)buttonClicked {
// Return if one click is already in process
if (self.isButtonClicked) {
return;
}
self.isButtonClicked = YES:
timer = [NSTimer scheduledTimerWithTimeInterval:0.2 target:self
selector:#selector(timerClicked) userInfo:nil repeats:YES];
imgviewtransparent.image = [UIImage imageNamed:[imagesArray objectAtIndex:i]];
}
-(void)timerClicked {
[timer invalidate];
timer = nil;
self.isButtonClicked = NO;
}