Question

我希望将UIImage拖到几个UIButton中的一个上，并根据我拖动它的按钮重新定位它。

我遇到的问题是UITouch只记录触摸开始的视图，我想访问我的触摸结束的视图。我怎么能这样做？

代码：

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

    dealerBtnOrigin = [touch locationInView:self.view];

    //NSLog(@"%u %u",touch.view.tag, ((UIView *)[dealerBtns objectAtIndex:[table getButtonSeat]]).tag);
    //CHECK TO SEE WHICH BUTTON WAS TOUCHED
    if (touch.view == ((UIView *)[dealerBtns objectAtIndex:[table getButtonSeat]]))
    {
        ((UIView *)[dealerBtns objectAtIndex:[table getButtonSeat]]).center = location;
    }
}

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


    if (touch.view == ((UIView *)[dealerBtns objectAtIndex:[table getButtonSeat]]))
    {
        ((UIView *)[dealerBtns objectAtIndex:[table getButtonSeat]]).center = location;
    }
}

-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [touches anyObject];
    CGPoint location = [touch locationInView:self.view];
    UIView *endView = [self.view hitTest:location withEvent:nil];

    if (touch.view == ((UIView *)[dealerBtns objectAtIndex:[table getButtonSeat]]))
    {
        NSLog(@"%u %u",endView.tag, touch.view.tag);
        if([buttons containsObject:(UIButton *)endView])
        {
            [[dealerBtns objectAtIndex:[table getButtonSeat]] setHidden:YES];
            [table passButton:touch.view.tag];
            [[dealerBtns objectAtIndex: touch.view.tag] setHidden:NO];
        }
        ((UIView *)[dealerBtns objectAtIndex:[table getButtonSeat]]).center = dealerBtnOrigin;
    }

}

Answer 1

使用命中测试。根据最终超级视图self.view，您知道此点作为CGPoint的位置。然后，您可以询问self.view指向哪个子视图：

CGPoint location = [touch locationInView:self.view];
UIView* v = [self.view hitTest:location withEvent:nil];

UIView v是您正在寻找的视图。

Answer 2

检测最终触摸的视图非常容易，请尝试使用此代码

-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    CGPoint location = [[touches anyObject] locationInView:self.view];
    CGRect fingerRect = CGRectMake(location.x-5, location.y-5, 10, 10);

    for(UIView *view in self.view.subviews){
        CGRect subviewFrame = view.frame;

        if(CGRectIntersectsRect(fingerRect, subviewFrame)){
            //we found the finally touched view
            NSLog(@"Yeah !, i found it %@",view);
        }

    }

}

Answer 3

通常，您需要确定触摸结束的点，并确定它是否位于您感兴趣的视图中。我使用类似于以下的代码执行此操作：

CGPoint newCenter = dragView.center;
for (UIView *v in dropTargets)
{
    CGRect convertedTargetFrame = [v.superview convertRect:v.frame toView:nil];
    if (CGRectContainsPoint(convertedTargetFrame, newCenter))
    {
        activeTargetIndex = idx;
    }
}

（这段代码是动态编辑的，可以删除很多无关紧要的内容，但是我在dropTargets中保留了一个潜在的drop目标列表，这只是查看该列表以查看哪些潜在的UIViews可能包含点）。

重要的是，如果您知道可能将项目拖动到的视图或视图，则可以使用CGRectContainsPoint确定该视图的框架是否包含该点。重要的是要记住它们可能位于不同的坐标系中，在比较之前可能需要从一个坐标系转换为另一个坐标系。

Answer 4

假设容器中有@property个目标视图，并且目标视图已添加到容器中：

@property (nonatomic, strong) UIView* targetView;

// ...

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    NSSet* touchesForTargetView = [event touchesForView:self.targetView];
    if (touchesForTargetView.allObjects.count != 0) {
        // touch was at target view
    }
    else {
        // touch  was somewhere else
    }    
}

Answer 5

斯普利特4：

覆盖func touchesEnded（_ touches：Set，with event：UIEvent？）{

''

//继续.. }

    if let touch = touches.first{
        let location = touch.location(in: self.view)
        let v = touch.view

如何找出触摸事件结束的视图？

5 个答案: