Question

我有一个UILabel在第一次加载时没有更新，但在其他所有后续加载时都会正确加载。

以下是代码片段。同样，正如我所说，在第一次加载时，它只显示xib中标签中指定的内容，即label，第二次加载字符串label.text= @"Glass, Paper, Cans, Textiles, Card, Shoes and Books";。

-(IBAction)showDetails:(id)sender{
    NSLog(@"Annotation Click");
    self.userProfileVC.title=((UIButton*)sender).currentTitle;
    if([((UIButton*)sender).currentTitle isEqualToString:@"Asda"])
        self.userProfileVC.label.text= @"Glass, Paper, Cans, Textiles, Card, Shoes and Books";

    [UIView beginAnimations:@"Curl Page Down" context:nil];
    [UIView setAnimationDuration:1];
    [UIView setAnimationTransition:UIViewAnimationTransitionCurlDown 
                       forView:self.view cache:YES];    

    //Adjust the Subview by butting up to status bar
    self.userProfileVC.view.frame = CGRectMake(0, 0, 320, 480);
    //Add userProfileVC as a subview
    [self.view addSubview:userProfileVC.view];
    [UIView commitAnimations];
}

Answer 1

当您单击UIButton时，可能会调用此代码。所以在第一次UI加载时我不希望你的方法被调用（因为没有按下按钮）。为什么不尝试设置viewDidLoad或类似的默认文字？

e.g。类似的东西：

- (void)viewDidLoad {
    self.userProfileVC.label.text= @"Glass, Paper, Cans, Textiles, Card, Shoes and Books";
}

Answer 2

我相信，当您第一次访问self.userProfileVC.label时，label仍然是nil，因为视图本身尚未加载。快速解决方法是，您必须首先在self.userProfileVC.view;方法的开头添加showDetails语句来加载视图。

Answer 3

我是个白痴我已经改变了我的代码的顺序....在标签之前加载视图。 DOH！

下面是片段：

- （IBAction为）showDetails：（ID）发送方{

//Must load the view before the annotations update the label with the correct label text!
[UIView beginAnimations:@"Curl Page Down" context:nil];
[UIView setAnimationDuration:1];

[UIView setAnimationTransition:UIViewAnimationTransitionCurlDown 
                       forView:self.view cache:YES];    

//Adjust the Subview by butting up to status bar
self.userProfileVC.view.frame = CGRectMake(0, 0, 320, 480);
//Add userProfileVC as a subview
[self.view addSubview:userProfileVC.view];
[UIView commitAnimations];

NSLog(@"Annotation Click");
self.userProfileVC.title=((UIButton*)sender).currentTitle;
if([((UIButton*)sender).currentTitle isEqualToString:@"Asda"])
    self.userProfileVC.label.text= @"Glass, Paper, Cans, Textiles, Card, Shoes and Books";

iPhone UILabel首次加载时无法更新

3 个答案: