某些按钮未通过 hitTest

Question

我的界面有时周围有按钮。没有按钮的区域接受手势。

GestureRecognizers 被添加到容器视图中，在 viewDidLoad 中。以下是 tapGR 的设置方式：

UITapGestureRecognizer *tapGR = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(playerReceived_Tap:)];
[tapGR setDelegate:self];
[self.view addGestureRecognizer:tapGR];

为了防止手势识别器拦截按钮点击，我实现了 shouldReceiveTouch 以仅在触摸的视图不是按钮时返回 YES：

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gr 
   shouldReceiveTouch:(UITouch *)touch {

    // Get the topmost view that contains the point where the gesture started.
    // (Buttons are topmost, so if they were touched, they will be returned as viewTouched.)
    CGPoint pointPressed = [touch locationInView:self.view];
    UIView *viewTouched = [self.view hitTest:pointPressed withEvent:nil];

    // If that topmost view is a button, the GR should not take this touch.
    if ([viewTouched isKindOfClass:[UIButton class]])
        return NO;

    return YES;

}

这在大多数情况下都可以正常工作，但有一些按钮没有响应。当这些按钮被点击时，hitTest 返回的是容器视图，而不是按钮，所以 shouldReceiveTouch 返回 YES 并且gestureRecognizer 控制事件。

为了调试，我运行了一些测试...

以下测试确认按钮是容器视图的子子视图，它已启用，并且按钮和子视图都是 userInteractionEnabled：

-(BOOL)gestureRecognizer:(UIGestureRecognizer *)gr 
   shouldReceiveTouch:(UITouch *)touch {

// Test that hierarchy is as expected: containerView > vTop_land > btnSkipFwd_land.
for (UIView *subview in self.view.subviews) {
    if ([subview isEqual:self.playComposer.vTop_land])
        printf("\nViewTopLand is a subview."); // this prints
}
for (UIView *subview in self.playComposer.vTop_land.subviews) {
    if ([subview isEqual:self.playComposer.btnSkipFwd_land])
        printf("\nBtnSkipFwd is a subview."); // this prints
}

// Test that problem button is enabled.
printf(“\nbtnSkipFwd enabled? %d", self.playComposer.btnSkipFwd_land.enabled); // prints 1

// Test that all views in hierarchy are interaction-enabled.
printf("\nvTopLand interactionenabled? %d", self.playComposer.vTop_land.userInteractionEnabled); // prints 1
printf(“\nbtnSkipFwd interactionenabled? %d", self.playComposer.btnSkipFwd_land.userInteractionEnabled); // prints 1

// etc

}

以下测试确认按下的点实际上在按钮的框架内。

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gr 
   shouldReceiveTouch:(UITouch *)touch {

CGPoint pointPressed = [touch locationInView:self.view];
CGRect rectSkpFwd = self.playComposer.btnSkipFwd_land.frame;

// Get the pointPressed relative to the button's frame.
CGPoint pointRelSkpFwd = CGPointMake(pointPressed.x - rectSkpFwd.origin.x, pointPressed.y - rectSkpFwd.origin.y);
printf("\nIs relative point inside skipfwd? %d.", [self.playComposer.btnSkipFwd_land pointInside:pointRelSkpFwd withEvent:nil]); // prints 1

// etc

}

那么为什么 hitTest 返回的是容器视图而不是这个按钮呢？

解决方案：我没有测试的一件事是中间视图 vTop_land 的构图正确。它看起来不错，因为它的图像延伸到屏幕上——超出了框架的边界（我不知道这是可能的）。框架设置为纵向宽度，而不是横向宽度，因此最右侧的按钮超出区域。

Answer 1

命中测试在大多数情况下并不可靠，通常不建议将其与手势识别器一起使用。

你为什么不为每个按钮setExclusiveTouch:YES，这应该确保按钮总是被选中。