uiviewcontroller解除分配时如何在目标c中触发阻止事件 | iviewcontroller解除分配时如何在目标c中触发阻止事

本文介绍了uiviewcontroller解除分配时如何在目标c中触发阻止事件的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

如何在UIViewController取消分配时在目标C中触发阻止事件.

How to fire block event in Objective C when UIViewController dealloc.

例如:

   [PGMemberObj requestWithUserName:@"ab" andPassword:@"cc" andCallback:^(BOOL isSuc){
        if (isSuc) {
            NSLog("Login Suc.");
        }else
        {
            NSLog("Login Failed");
        }
    }];

当我弹出ViewController并执行dealloc时，我仍然收到Login Suc.或登录失败消息.如何避免这个问题?

when i pop ViewController and dealloc was executed,i still receive Login Suc. or Login Failed Message.How to avoid this issue?

推荐答案

尝试以下代码:

__weak UIViewController *weakSelf = self;
[PGMemberObj requestWithUserName:@"ab" andPassword:@"cc" andCallback:^(BOOL isSuc){
    if ([weakSelf isViewLoaded] && [weakSelf.view window])
        //The view controller still exists AND it's being shown on screen
    else
        //Either dealloc'd or not on screen anymore
 }];

它将测试您的视图控制器是否仍然存在并且仍在屏幕上.只需检查weakSelf，如果您不在乎它是否仍在屏幕上显示.

It will test whether your view controller still exists AND is still on screen.Just check for weakSelf if you don't care if it's still being shown on screen.

if (weakSelf)
    //Still exists
else
    //dealloc'd

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