iphone - UITouch，拖放根本不起作用

Question

我有一个 UIView，在他上面我有 UIButton、UITableView 和 UINavigationBar。我想要做的是，当您单击 UIButton 并拖动它时，所有 View 将仅移动到左侧，直到屏幕结束。我的意思是，您可以向左拖动 View ，当您停止触摸时， View 将停止在您手指停止触摸屏幕的位置。

我做不到，他只给我看了“Touches Began 1”，仅此而已。我的问题是什么？

非常感谢大家!

float oldX, oldY;
BOOL dragging;

- (void)touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event
{
    NSLog("Touches Began 1");
    UITouch *touch = [[event allTouches] anyObject];
    CGPoint touchLocation = [touch locationInView:self.view];

    if (CGRectContainsPoint(btnOpen.frame, touchLocation))
    {
        NSLog("Touches Began 2");
        dragging = YES;
        oldX = touchLocation.x;
        oldY = touchLocation.y;
    }
}

- (void) touchesMoved:(NSSet*)touches withEvent:(UIEvent*)event
{
    UITouch *touch = [[event allTouches] anyObject];
    CGPoint touchLocation = [touch locationInView:self.view];

    if (dragging)
    {
        NSLog("Dragging!");
        CGRect frame = mainView.frame;
        frame.origin.x = mainView.frame.origin.x + touchLocation.x - oldX;
        frame.origin.y =  mainView.frame.origin.y + touchLocation.y - oldY;
        mainView.frame = frame;
    }
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    NSLog("Touches Ended!");
    dragging = NO;
}


- (void)viewDidLoad
{    
    [btnOpen addTarget:self action:@selector(touchesBegan:withEvent:) forControlEvents: UIControlEventTouchDown];
    [btnOpen addTarget:self action:@selector(touchesMoved:withEvent:) forControlEvents: UIControlEventTouchDragInside];
    [btnOpen addTarget:self action:@selector(touchesEnded:withEvent:) forControlEvents: UIControlEventTouchUpInside | UIControlEventTouchUpOutside];
}

Answer 1

您要求的是触摸相对于主视图框架的坐标

CGPoint touchLocation = [touch locationInView:self.view];

然后你询问 touchLocation 的位置是否在按钮框架的框架内

if (CGRectContainsPoint(btnOpen.frame, touchLocation))

换句话说。您正在检查触摸是否在按钮的范围内，但您检查的是在主视图而不是按钮上进行的触摸坐标。

所以这是你应该做的:

CGPoint touchLocation = [touch locationInView:btnOpen];