查找UIGestureRecognizer操作（选择器）名称和目标

问题描述

我正在尝试查找UIGestureRecognizer在哪个目标上触发了哪个操作。很遗憾， UIGestureRecognizer 上没有属性，例如 gesture.action 或 gesture.target 。我正在分析的手势是UIKit私人实施的一部分。

I'm trying to find which action is triggered by a UIGestureRecognizer on which target. Unfortunately there is no property on a UIGestureRecognizer such as gesture.action or gesture.target. The gesture I'm analyzing is part of UIKit private implementation.

这里的部分答案

推荐答案

这是一个代码片段，列出与手势识别器关联的所有目标/动作对：

Here's a code snippet that will list all target/action pairs associated with a gesture recognizer:

Ivar targetsIvar = class_getInstanceVariable([UIGestureRecognizer class], "_targets");
id targetActionPairs = object_getIvar(gesture, targetsIvar);

Class targetActionPairClass = NSClassFromString(@"UIGestureRecognizerTarget");
Ivar targetIvar = class_getInstanceVariable(targetActionPairClass, "_target");
Ivar actionIvar = class_getInstanceVariable(targetActionPairClass, "_action");

for (id targetActionPair in targetActionPairs)
{
    id target = object_getIvar(targetActionPair, targetIvar);
    SEL action = (__bridge void *)object_getIvar(targetActionPair, actionIvar);

    NSLog(@"target=%@; action=%@", target, NSStringFromSelector(action));
}

请注意，您必须导入< objc / runtime.h> ，并且这使用了私有的ivars和一个类，所以它可以让你从App Store中被禁止。

Note that you'll have to import <objc/runtime.h>, and that this uses private ivars and a class, so it could get you banned from the App Store.

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