ios - pressGestureRecognizer 和 touchesBegan

Question

我有以下问题。 我正在使用 UILongPressGestureRecognizer 将 UIView 置于“切换模式”。如果 UIView 处于“切换模式”，用户可以在屏幕上拖动 UIView。为了在屏幕上拖动 UIView，我使用了方法 touchesBegan、touchesMoved 和 touchesEnded。

它有效，但是:我必须抬起手指才能拖动它，因为 touchesBegan 方法已经被调用，因此不会再次调用，因此我无法拖动 UIView 环绕屏幕。

在 UILongPressGestureRecognizer 被触发后，有没有办法手动调用 touchesBegan(UILongPressGestureRecognizer 改变了一个 BOOL 值并且 touchesBegan 仅当此 BOOL 设置为 YES 时才有效。

Answer 1

UILongPressGestureRecognizer 是一个连续的手势识别器，因此与其求助于 touchesMoved 或 UIPanGestureRecognizer，不如检查 UIGestureRecognizerStateChanged，例如:

- (void)viewDidLoad
{
    [super viewDidLoad];

    UILongPressGestureRecognizer *gesture = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleGesture:)];
    [self.view addGestureRecognizer:gesture];
}

- (void)handleGesture:(UILongPressGestureRecognizer *)gesture
{
    CGPoint location = [gesture locationInView:gesture.view];

    if (gesture.state == UIGestureRecognizerStateBegan)
    {
        // user held down their finger on the screen

        // gesture started, entering the "toggle mode"
    }
    else if (gesture.state == UIGestureRecognizerStateChanged)
    {
        // user did not lift finger, but now proceeded to move finger

        // do here whatever you wanted to do in the touchesMoved
    }
    else if (gesture.state == UIGestureRecognizerStateEnded)
    {
        // user lifted their finger

        // all done, leaving the "toggle mode"
    }
}