将对象从另一个视图控制器添加到数组 [英] Add objects to an Array from another View Controller

问题描述

我有一个 HomeViewController，它有一个 tableView，其中填充了数组 tableViewArray(最初为空).当我点击一个 barButton 时，我会模态地转到另一个名为 OutsideViewController 的视图控制器，它有另一个由不同数组填充的 tableView.

I have a HomeViewController which has a tableView populated with the array tableViewArray (originally empty). When I tap on a barButton, I segue modally to another View Controller called OutsideViewController which has another tableView populated by a different array.

我想做的是:

当我点击 OutsideViewController 中的一行时，我想将选定的字符串值添加到 tableViewArray 以便当我回到 HomeViewController，tableView 在 tableView 中列出了那个新项目.

When I tap on a row in my OutsideViewController, I would like to add the selected string value to the tableViewArray so that when I go back to HomeViewController, the tableView has that new item listed in the tableView.

到目前为止，这是我尝试过的:

So far, this is what I have tried:

在我的 OutsideViewController.m 的 -didSelectRowAtIndexPath 方法中，我有这段代码:

In the -didSelectRowAtIndexPath method of my OutsideViewController.m I have this piece of code:

NSString *selectedRow = [outsideArray objectAtIndex:indexPath.row];
NSMutableArray *temporaryArray = [NSMutableArray arrayWithObject:selectedRow];

HomeViewController *homeVC = [[HomeViewController alloc] init];
homeVC.tableViewArray = temporaryArray;

该代码有效，但是当我返回时 HomeViewController 中的 tableView 仍然是空的.我必须重新加载 tableView 数据吗?我这样做对吗?

That code works but the tableView in HomeViewController is still empty when I return. Do I have to reload the tableView data? Am I doing this right?

这是我在 Storyboard 中设置视图控制器的方式:

This is how I have set up my View Controllers in Storyboard:

HomeViewController -(modal segue)-> Navigation Controller --> OutsideViewController

另外，从OutsideViewController到HomeViewController的返回是通过这行代码完成的:

Also, the return from OutsideViewController to HomeViewController is done by this line of code:

[self dismissViewControllerAnimated:YES completion:^{ }];

推荐答案

你做错了什么是你分配了一个新的 HomeViewController.我要做的是在您的 OutsideViewController 中保留对您的 HomeViewController 的引用.方法如下.

What you're doing wrong is you're allocationg a new HomeViewController. What I would do is keeep a reference to your HomeViewController in your OutsideViewController. Here is how.

首先，在OutsideViewController.h中，创建一个属性，像这样:

First, in OutsideViewController.h, create a property, like this :

@property (nonatomic, weak) HomeViewController *homeVC;

不要忘记在 .h 中添加 @class HomeViewController;，在 .m 中添加 #import "HomeViewController.h"

Don't forget to add @class HomeViewController; in your .h, and #import "HomeViewController.h" in your .m

在HomeViewController中，像这样实现prepareForSegue:方法(用你的segue的标识符替换ModalSegueIdentifier):

In HomeViewController, implement the prepareForSegue: method like this (replace ModalSegueIdentifier with your segue's identifier) :

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    if ([segue.identifier isEqualToString:@"ModalSegueIdentifier"]) {
        OutsideViewController *modalVC = (OutsideViewController*)segue.destinationViewController;
        modalVC.homeVC = self;
    }
}

然后，在 OutsideViewController.m 中，而不是这样做:

Then, in OutsideViewController.m, instead of doing :

HomeViewController *homeVC = [[HomeViewController alloc] init];
homeVC.tableViewArray = temporaryArray;

这样做:

_homeVC.tableViewArray = temporaryArray;

当您离开模态 VC 时，您的 HomeVC 将拥有正确的数组.不要忘记刷新你的 UITableView ！

When you leave your modal VC, your HomeVC will have the correct array. Don't forget to refresh your UITableView !

注意:当然，还有很多其他方法，但可能不是最好的方法.但是，它应该可以工作.

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