如何从另一个ViewController保存后刷新rootViewController

Question

在一个简单的基于tableview的应用程序中，我有一个addItem按钮，可以打开另一个viewController，我可以在其中添加数据然后保存。问题是单击保存后新记录不会显示在tableView中。我已经尝试使用委托来刷新表，但也无法使用它。我可以看到添加到tableview的新记录的唯一方法是关闭应用程序并重新启动。见下文。

#bookingForm textarea

Answer 1

这是一个使用协议的例子以及我想要做的事情。

// firstViewController.h 

#import "secondViewController.h"

@interface firstViewController : UIViewController <secondViewControllerDelegate>

@end

// firstViewController.m

@implementation firstViewController

// will be called by delegate
- (void)refreshTable
{
    // get fresh/updated data from your sqlite before refresh, to get the currently added data...

    self.dataSource = [yourFreshDataFromSqlite];

    [self.targetTable reloadData];
}
//..

- (void)someInstance
{
    secondViewController *svc = [[secondViewController alloc] init];

    svc.delegate = self; // this is very important

    [self.navigationController pushViewController:svc animated:YES];
}

@end

// secondViewController.h 

@protocol secondViewControllerDelegate <NSObject>

- (void)refreshTable;

@end 

@interface secondViewController : UIViewController 
{
    BOOL mustRefresh;
}

@property (weak) id <secondViewControllerDelegate> delegate;

@end

// secondViewController.m

- (void)someOtherInstance
{
    mustRefresh = YES; // there is new record
}

- (void) save_Clicked:(id)sender 
{
    // ..
    [self.navigationController dismissViewControllerAnimated:YES completion: ^{

        if (mustRefresh) // this also important, checks is you need to reload the table from the firstController
            if ([self.delegate respondsToSelector:@selector(refreshTable)]) // this is just for check if 'refreshTable responds', prevents from crashing
                    [self.delegate refreshTable];

    }];
}

这是我得到的日志..

希望我在这里错过了什么..嗯......干杯......