NSUserDefaults不工作......还是我？

Question

所以我试图在视图之间传递一个url.每当用户从tableview中进行选择时,我就会想到以下代码会踩到@"url"中的任何内容.实际发生的是第一次选择总是被返回并且永远不会被踩踏.嗯,也许是我？有任何想法吗？谢谢.

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (indexPath.row == 0)
    {
        [self saveToUserDefaults:@"http://url1"];
        [self.navigationController pushViewController:self.webController animated:YES];
    }
    else if (indexPath.row == 1)
    {
        [self saveToUserDefaults:@"http://url2"];
        [self.navigationController pushViewController:self.webController animated:YES];
    }
}

-(void)saveToUserDefaults:(NSString*)myString
{
    NSUserDefaults *standardUserDefaults = [NSUserDefaults standardUserDefaults];

    if (standardUserDefaults) 
    {
        [standardUserDefaults setObject:myString forKey:@"url"];
        [standardUserDefaults synchronize];
    }
}

在接收端:

-(NSString*)retrieveFromUserDefaults
{
    NSUserDefaults *standardUserDefaults = [NSUserDefaults standardUserDefaults];
    NSString *val = nil;

    if (standardUserDefaults) 
        val = [standardUserDefaults objectForKey:@"url"];

    return val;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
    NSString *url = self.retrieveFromUserDefaults;
    [self handleURLRequest:url];
}

Answer 1

viewDidLoad仅在最初从xib文件加载视图时调用.如果弹出并重新推动视图控制器,则除非您收到内存不足警告,否则不会再次执行该方法.

viewWillAppear每当您的视图出现时,移动保证要调用的代码.