尝试移动UIImageView，移动整个屏幕视图

Question

I want my UIViewImages to be movable with touch. I'm trying to use code implemented in my ViewController:

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
}

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
    if ([touches count]==1) {
        UITouch *touch = [touches anyObject];
        CGPoint p0 = [touch previousLocationInView:self.view];
        CGPoint p1 = [touch locationInView:self.view];
        CGPoint center = self.view.center;
        center.x += p1.x - p0.x;
        center.y += p1.y - p0.y;
        self.view.center = center;
    }
}

When I try to drag an UIImageView, I'm dragging whole screen, which is incorrect. Need help!

Karol

Answer 1

You create a gesture recognizer and add it to a view like this:

UIPanGestureRecognizer *panGestureRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(gestureRecognizerMethod:)];
[self.imageView addGestureRecognizer:panGestureRecognizer];

you can adjust the position of the image view

- (void)gestureRecognizerMethod:(UIPanGestureRecognizer *)recogniser
{
    if (recognizer.state == UIGestureRecognizerStateBegan || recognizer.state == UIGestureRecognizerStateChanged)
    {
        CGPoint touchLocation = [recognizer locationInView:self.view];
        self.imageView.center = touchLocation;
    }
}

read this article.

Answer 2

If I read your code right self.view actually IS the whole screen. Maybe you mean self.yourImageView instead?