increase a value while uibutton is kept pressing in iphone - iphone

Question

I am trying to increase a variable's value while uibutton is kept pressing. But when user leaves button, increasing of variable's value will be stopped.
i have tried using threads with touch down and touchupinside but couldn't make it work.
-(void) changeValueOfDepthFields:(UIButton *)sender {
if (pressing)
pressing = NO;
else
pressing = YES;
pressingTag = 0;
while (pressing) {
[NSThread detachNewThreadSelector:#selector(increaseValue) toTarget:self withObject:nil];
}
}
- (void) stopValueChange:(UIButton *)sender {
pressing = NO;
}
[fStopUp addTarget:self action:#selector(changeValueOfDepthFields:) forControlEvents:UIControlEventTouchDown];
[fStopUp addTarget:self action:#selector(stopValueChange:) forControlEvents:UIControlEventTouchUpInside];
- (void) increaseValue {
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
fstopVal = fstopVal + 0.1;
[self performSelectorOnMainThread:#selector(changeTextOfValues) withObject:nil waitUntilDone:YES];
[pool release];
}
- (void) changeTextOfValues {
fStopField.text = [NSString stringWithFormat:#"%.02f", fstopVal];
}
I wonder if there is an alternative way to do this or not. It seems very simple but couldn't think of any other solution than this one.

Answer 1

It is much easier to use an NSTimer.
- (void)changeValueOfDepthFields:(UIButton *)sender
{
if (!self.timer) {
self.timer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:#selector(increaseValue) userInfo:nil repeats:YES];
}
}
- (void)stopValueChange:(UIButton *)sender
{
if (self.timer) {
[self.timer invalidate];
self.timer = nil;
}
}
- (void)increaseValue
{
fstopVal = fstopVal + 0.1;
fStopField.text = [NSString stringWithFormat:#"%.02f", fstopVal];
}
Note: The previous code is just for reference, I didn't do any memory management for example.