我的界面有时在其外围有按钮。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才返回 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，但是有一些按钮没有响应。当这些按钮被点击时，hitTest 返回容器视图，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 的框架正确。它看起来不错，因为它有一个横跨屏幕的图像——超过了它的框架边界（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了区域。