ios - UITouch 不释放 View

Question

我有一个未被释放的自定义 View 。我在按下关闭按钮时关闭 Controller 。现在，如果我只按下按钮， View 就会被解除分配。但是，如果用一根手指按下按钮，另一根手指触摸 View ，则它不会在关闭时释放，而是在下一次触摸事件时释放。

它的 UITouch 保留我的 View 的引用而不释放它。我怎样才能解决这个问题？

这是我关闭操作的代码:

- (IBAction)closePressed:(UIButton *)sender {
    NSLog(@"Close pressed"); 
    if (self.loader)
    [self.loader cancelJsonLoading];
    [self.plView quit];
    [self dismissViewControllerAnimated:YES completion:nil];
}

Answer 1

你试过打电话吗:

[self.view resignFirstResponder];

这应该会取消所有挂起的 UITouches。

如果这不起作用，您可以记录您的触摸:

• 定义一个 NSMutableSet，用于存储当前触摸:

  NSMutableSet *_currentTouches;

• 在你的 init() 中:

  _currentTouches = [[NSMutableSet alloc] init];

并实现:

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    [super.touchesBegan:touches withEvent:event];
    [_currentTouches unionSet:touches]; // record new touches
}

- (void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    [super.touchesEnded:touches withEvent:event];
    [_currentTouches minusSet:touches]; // remove ended touches
}

- (void)touchesCancelled:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    [super.touchesEnded:touches withEvent:event];
    [_currentTouches minusSet:touches]; // remove cancelled touches
}

然后，当您需要清除触摸时(例如，当您释放 View 时):

- (void)cleanCurrentTouches {
    self touchesCancelled:_currentTouches withEvent:nil];
    _currentTouchesremoveAllObjects];
}

我认为这有点 hacky，但文档说:

When an object receives a touchesCancelled:withEvent: message it should clean up any state information that was established in its touchesBegan:withEvent: implementation.