本文介绍了将方法添加到UINavigationBar后退按钮?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

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如何将方法添加到UINavigationbar后退按钮,所以每当我点击后退按钮时,我需要检查一些值并显示UIAlertView?有什么选择吗?

How can i add method to UINavigationbar back button, so whenever I click that back button I need to check some values and show UIAlertView? Is there any option for this?

我尝试过这种方法,但它适用于我

i tried this method but its working for me

  - (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated
    {
    //show alert
    }

以及这种方法,但两者都没有工作

and also this method but both are not woking

-(void) viewWillDisappear:(BOOL)animated {
    if ([self.navigationController.viewControllers indexOfObject:self]==NSNotFound) {
        // back button was pressed.  We know this is true because self is no longer
        // in the navigation stack.
         NSLog(@"hi");
    }


推荐答案

是的你可以
在viedDidLoad中

Yes you canIn viedDidLoad

UIBarButtonItem * backBtn = [[UIBarButtonItem alloc]initWithTitle:@"Back" style:UIBarButtonItemStyleBordered target:self action:@selector(goBackToAllPets:)];

    self.navigationItem.leftBarButtonItem = backBtn;

编写以下函数来检查条件

write following function to check condition

-(void)goBackToAllPets:(id)sender
{
    if(/*check condition*/)
    {
        UIAlertView *alert = [[UIAlertView alloc]initWithTitle:nil message:@"message" delegate:self cancelButtonTitle:@"No" otherButtonTitles:@"Yes", nil];
        alert.tag = 0;
        [alert show];


    }
    else
    {
        [self.navigationController popViewControllerAnimated:YES];
    }


}

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1403页,肝出来的..

09-06 19:40