如何将数据从先前的序列传递到子视图控制器? [英] How to pass data to a child view controller from a previous segue?

问题描述

我需要从View Controller to a child of a parent view controller.

prepareSegue不会传递数据.

我需要在viewdidload之前通过它.

i need to have it passed before viewdidload.

这是我试图将信息从View Controller传递给父级孩子的方式.

here is how im trying to pass info from a View Controller to a Child of a Parent.

-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
   // NSLog(@"prepareForSegue: %@",segue.identifier);

    ViewController2 *transfer = segue.destinationViewController;

    if ([segue.identifier isEqualToString:@"Test"]) {
        transfer.testLabel = @"Pass this data";
    }
}

推荐答案

选项1

如果要从父级传递给子级视图控制器，则只需从父级设置childViewController的属性.

If you're passing from a parent to a child view controller, then just set the property of your childViewController from the parent.

customChildViewController.someRandomProperty = @"some random value";
[self presentViewController:customChildViewController animated:YES completion:nil];

选项2

或者，您可以设置一个代表人

Or, you can set up a delegate

步骤1 :在ChildViewController.h文件的接口上方设置协议

Step 1: set up protocol above interface in ChildViewController.h file

@protocol ChildViewControllerDelegate

- (NSDictionary *) giveMeData;

@end

@interface  .....

第2步:在ChildViewController.h接口中创建委托属性

Step 2: create delegate property in ChildViewController.h interface

@property (strong, nonatomic) id<ChildViewControllerDelegate>delegate

步骤3 :在ParentViewController.h中声明委托协议

Step 3: declare delegate protocol in ParentViewController.h

@interface ParentViewController : UIViewController <ChildViewControllerDelegate>

第4步:在ParentViewController.m中添加此方法:

Step 4: in ParentViewController.m add this method:

- (NSDictionary *) giveMeData {
    NSMutableDictionary * dataToReturn = [[NSMutableDictionary alloc]init];
    dataToReturn[@"some"] = @"random";
    dataToReturn[@"data"] = @"here";
    return dataToReturn;
}

步骤5 :在启动childViewController之前，请声明委托属性.

Step 5: before launching childViewController declare delegate property.

childViewController.delegate = self;
[self presentViewController:childViewController animated:YES completion:nil];

步骤6 :在子视图控制器中，只要您想添加数据

Step 6: in child view controller whenever you want data add this

NSMutableDictionary * dataFromParent = [self.delegate giveMeData];

parentVC将运行'giveMeData'并返回NSMutableDictionary(根据您想要的任何数据进行调整)

The parentVC will run 'giveMeData' and return a NSMutableDictionary (adjust for whatever data you want)

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