表视图在从其他视图中关闭后不显示从 plist 加载的新数据

Question

我的第一个视图是一个UIView控制器，我有一个UITable视图，它工作得很好。

从第一个视图中我推送另一个视图，在该视图中我选择一个组名

然后视图关闭，我想要的是当我从第二个视图中选择组名称时，第一个视图将该组名的值加载到表视图中，这是我使用的代码，它不起作用

第二个视图代码

- (IBAction)sendNames:(id)sender {
if (!keyValue) {
    NSLog(@"Didnt Select Any Group To Send");
    return;
}
ViewController *theInstance = [[ViewController alloc] init];
[theInstance setGroupName:keyValue];
[theInstance ReceivedGroup:nil];
[self dismissViewControllerAnimated:YES completion:nil];
//tried that option and didnt work too, i added the rest of the code in the viewDidLoad
//[[NSNotificationCenter defaultCenter] postNotificationName:@"RG" object:nil];
}

keyValue 是 NSString 在 tableView didSelectRowAtIndexPath 上设置的 NSString

第一个视图

- (IBAction)ReceivedGroup:(id)sender {    
NSString *path = [self dataFilePath];
NSDictionary *dict = [NSDictionary dictionaryWithContentsOfFile:path];
NSArray *tempArray = [dict objectForKey:groupName];
nameArray = [[NSMutableArray alloc] init];
[nameArray addObjectsFromArray:tempArray];
[nameTable reloadData];
NSLog(@"Group Name : %@",groupName);
NSLog(@"Array : %@",nameArray);
}

组名是 NSString

在日志中，我打印了组名称和名称数组

但表视图是空的。

编辑：我解决了问题并发布了我的答案

Answer 1

您的视图控制器"theInstance"将在调用 sendNames 后立即释放：因此不会发生任何事情。您应该将第一个视图控制器的指针传递给第二个视图控制器（例如，将其设置为属性），并在此视图控制器上执行所有操作。

子类 UITableViewController

@interface SecondViewController : UITableViewController
@property (nonatomic, strong) ViewController *firstViewController;
@end

如果使用情节提要 segue 在您的第一个查看器中实现：

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
   ((SecondViewController *) segue.destinationViewController).firstViewController = self;
}

sendNames： 应该看起来像这样：

- (IBAction)sendNames:(id)sender {
if (!keyValue) {
    NSLog(@"Didnt Select Any Group To Send");
    return;
}
ViewController *theInstance = self.firstViewController;
[theInstance setGroupName:keyValue];
[theInstance ReceivedGroup:nil];
[self dismissViewControllerAnimated:YES completion:nil];
//tried that option and didnt work too, i added the rest of the code in the viewDidLoad
//[[NSNotificationCenter defaultCenter] postNotificationName:@"RG" object:nil];
}

Answer 2

我通过使用NSNotificationCenter发送键值来修复它

这是我现在的代码

对于第二个视图

- (IBAction)sendNames:(id)sender {
   if (!keyValue) {
       NSLog(@"Didnt Select Any Group To Send");
       return;
   }
   [[NSNotificationCenter defaultCenter] postNotificationName:@"RG" object:keyValue];
   [self dismissViewControllerAnimated:YES completion:nil];
}

然后在第一视图上

- (void)receiveNotification:(NSNotification *)notification {
    NSString *Key = [notification object];
    nameArray = [[NSMutableArray alloc] init];
    [nameArray removeAllObjects];
    NSString *path = [self dataFilePath];
    NSDictionary *dict = [NSDictionary dictionaryWithContentsOfFile:path];
    NSArray *tempArray = [dict objectForKey:Key];
    [nameArray addObjectsFromArray:tempArray];
    [self.nameTable reloadData];
    NSIndexPath *indexPath = [NSIndexPath indexPathForRow:[nameTable numberOfRowsInSection:0] - 1 inSection:0];
    [nameTable scrollToRowAtIndexPath:indexPath atScrollPosition:UITableViewScrollPositionBottom animated:YES];
}
- (void)viewDidLoad {
    [super viewDidLoad];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(receiveNotification:) name:@"RG" object:nil];
}