如何以编程方式退回到2个不同的VC [英] How to unwind programmatically to 2 different VC

问题描述

如果您遇到三个ViewController的情况.黄色，绿色和白色.

If we have a situation where you have three ViewControllers. Yellow, green and white one.

您可以同时通过黄色和绿色获得白色.参见图片以获取更多说明:

You can get to the white one through both yellow and green one. See the picture for more clarification:

当我从黄色选为白色时，我准备进行搜索并将NSUinteger jimmy_hendrix值设置为0；

When I segue from yellow to white, I prepare for segue and set a NSUinteger jimmy_hendrix value to 0;

当我从绿色选为白色时，我准备进行选战并将NSUinteger jimmy_hendrix值设置为1；

When I segue from green to white, I prepare for segue and set a NSUinteger jimmy_hendrix value to 1;

在白色VC内，我制作了IBAction并将一个BACK按钮连接到它.在其中，根据值，我想平息我最终在白色VC中使用的segue.

Inside the white VC, I made IBAction and connected a BACK button to it. In there, depending on the value I want to unwind the segue which I ended up in the white VC.

这是我使用的代码:

- (IBAction)goBack:(UIButton *)sender {

switch (_jimmy_hendrix) {

    case 0:
        [self performSegueWithIdentifier:@"fromYellowToWhite" sender:self];
        break;

    case 1:
        [self performSegueWithIdentifier:@"fromGreenToWhite" sender:self];
        break;
}
}

但是，我得到一个例外:

But, I get an exception :

'Receiver (<WhiteVC: 0x15d8c850>) has no segue with identifier 'fromSuperTraenerToSuperTraenerQuestions

为清楚起见，我从不按ctrl键并从后退"按钮拖动以退出，然后选择unwind segue方法，因为我要根据我使用的VC和segue进行两次取消操作.

To make this clear, I never ctrl + dragged from the BACK button to exit and then selected the unwind segue method, because there are two unwinds I want to perform, based on which VC and which segue I used.

对此有什么解决方案? 如何选择回到我最初使用的任何ViewvController?

What is a solution to this? How to segue back to whichever ViewvController I used to get to my destionation on the first place?

重要提示:我知道我可以进行新的选择，从白色到黄色和绿色，然后将其命名.但是我不想那样.我不想做新的任务，我想以编程的方式放松现有的任务.

IMPORTANT: I know I can make new segues, from white to yellow and green and call them. But I don't want that..I don't want to make new segues, I want to programatically unwind the existing ones.

我忘了提到我确实在绿色和黄色VC中制作了展开方法

I forgot to mention that indeed I made unwind methods in green and yellow VC

-(IBAction)fromYellowToWhite:(UIStoryboardSegue *)segue {
}


-(IBAction)fromGreenToWhite:(UIStoryboardSegue *)segue {
}

推荐答案

您需要创建展开序列.在YellowVC中创建方法

You need to create the unwind segues. In YellowVC create a method

-(IBAction)fromYellowToWhite:(UIStoryboardSegue *)segue {
}

并在GreenVC中创建一个方法

and in GreenVC create a method

-(IBAction)fromGreenToWhite:(UIStoryboardSegue *)segue {
}

然后从White中的UIViewController实例拖动到White场景中的退出"图标，然后选择fromYellowToWhite.重复此操作，然后选择fromGreenToWhite:

Then drag from the UIViewController instance in White to the "exit" icon in the White scene and select fromYellowToWhite. Repeat this and select fromGreenToWhite:

最后，选择您新创建的Unse Segues，并将标识符设置为"fromYellowToWhite"和"fromGreenToWhite"-它们应具有"fromYellowToWhite:"和"fromGreenToWhite:"的操作"

Finally, select your newly created unwind Segues and set the identifiers to "fromYellowToWhite" and "fromGreenToWhite" - they should have an 'action' of "fromYellowToWhite:" and "fromGreenToWhite:"

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