I need to drag my UIView object. I use this code, but it does not work
float oldX, oldY;
BOOL dragging;
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [[event allTouches] anyObject];
CGPoint touchLocation = [touch locationInView:self];
if ([[touch.view class] isSubclassOfClass:[UILabel class]]) {
UILabel *label = (UILabel *)touch.view;
if (CGRectContainsPoint(label.frame, touchLocation)) {
dragging = YES;
oldX = touchLocation.x;
oldY = touchLocation.y;
}
}
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
dragging = NO;
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [[event allTouches] anyObject];
CGPoint touchLocation = [touch locationInView:self];
if ([[touch.view class] isSubclassOfClass:[UILabel class]]) {
UILabel *label = (UILabel *)touch.view;
if (dragging) {
CGRect frame = label.frame;
frame.origin.x = label.frame.origin.x + touchLocation.x - oldX;
frame.origin.y = label.frame.origin.y + touchLocation.y - oldY;
label.frame = frame;
}
}
}
I would suggest using a UIPanGestureRecognizer
:
-(void)dragging:(UIPanGestureRecognizer *)gesture
{
// Check if this is the first touch
if(gesture.state == UIGestureRecognizerStateBegan)
{
// Store the initial touch so when we change positions we do not snap
self.panCoord = [gesture locationInView:gesture.view];
[self.view bringSubviewToFront:gesture.view];
}
CGPoint newCoord = [gesture locationInView:gesture.view];
// Create the frame offsets to use our finger position in the view.
float dX = newCoord.x-self.panCoord.x;
float dY = newCoord.y-self.panCoord.y;
gesture.view.frame = CGRectMake(gesture.view.frame.origin.x+dX,
gesture.view.frame.origin.y+dY,
gesture.view.frame.size.width,
gesture.view.frame.size.height);
}
This is just a preference of mine. To me it is a lot simpler using a gesture recognizer then using touchesBegan
, touchesEnded
, touchesMoved
. I will use these in cases where the UIPanGestureRecognizer
will not work.