Question

我正在尝试检测用户何时在视图中向下触摸。该视图包含一些按钮和其他UIKit控件。我想检测这些触摸事件但不消耗它们。

我尝试了两种方法，但两种方法都不够：

首先，我添加了一个透明覆盖覆盖--touchesBegan：withEvent：和-touchesEnded：withEvent：并使用

将事件转发给下一个响应者

[self.nextResponder touchesBegan:touches withEvent:event]

但是，似乎UIKit对象忽略了所有转发的事件。

接下来，我尝试重写-pointInside：withEvent：和-hitTest：withEvent :.这对于检测触摸 down 事件非常有用，但是在触摸 up 时没有调用pointInside ::和hitTest ::（[[[all allTouches] anyObject]阶段]是永远不等于UITouchPhaseEnded。。

在不干扰与底层UIControl的交互的情况下，检测触地和触摸事件的最佳方法是什么？

Answer 1

根据Event Handling Guide for iOS 你有3个选择：

1）继承UIWindow以覆盖sendEvent：

2）使用叠加视图

3）设计，这样你就不必这样做......所以更像是2个选项。

以下是使用UIWindow子类的Apple示例的简化;

1）将NIB中窗口的类更改为UIWindow的子类。 2）将此方法放在.m文件中。

- (void)sendEvent:(UIEvent *)event
{
    NSSet * allTouches = [event allTouches];

    NSMutableSet *began = nil;
    NSMutableSet *moved = nil;
    NSMutableSet *ended = nil;
    NSMutableSet *cancelled = nil;

    // sort the touches by phase so we can handle them similarly to normal event dispatch
    for(UITouch *touch in allTouches) {
        switch ([touch phase]) {
            case UITouchPhaseBegan:
                if (!began) began = [NSMutableSet set];
                [began addObject:touch];
                break;
            case UITouchPhaseMoved:
                if (!moved) moved = [NSMutableSet set];
                [moved addObject:touch];
                break;
            case UITouchPhaseEnded:
                if (!ended) ended = [NSMutableSet set];
                [ended addObject:touch];
                break;
            case UITouchPhaseCancelled:
                if (!cancelled) cancelled = [NSMutableSet set];
                [cancelled addObject:touch];
                break;
            default:
                break;
        }

        // call our methods to handle the touches
        if (began)
        {
            NSLog(@"the following touches began: %@", began);
        };
        if (moved)
        {
            NSLog(@"the following touches were moved: %@", moved);
        };
        if (ended)
        {
             NSLog(@"the following touches were ended: %@", ended);
        };
        if (cancelled) 
        {
             NSLog(@"the following touches were cancelled: %@", cancelled);
        };
    }
    [super sendEvent:event];
}

它有太多的输出，但你会得到这个想法......并且可以使你的逻辑适合你想要的地方。

检测触地＆amp;在包含UIControls的视图中触摸

1 个答案: