UIActivityIndi​​cator not displayed

Question

我有一個FirstView加載了tableView，當點擊tableviewCell的附件按鈕時，它會去SecondView.TheView中的數據從服務url加載，所以它需要時間。所以我需要顯示activityIndi​​cator時accessorybutton被輕敲，加載整個數據後停止它.Bt我無法看到activityindicator顯示。

這是工作的代碼林：

- (void) tableView:(UITableView *)tableView accessoryButtonTappedForRowWithIndexPath:(NSIndexPath *)indexPath 
{ 

activityIndicator = [[UIActivityIndicatorView alloc]initWithFrame:CGRectMake(143, 220, 37, 37)]; 
activityIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyleGray; 
activityIndicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray]; 
activityIndicator.color = [UIColor redColor]; 
[scrollView addSubView:activityIndicator]; 
[activityIndicator startAnimating]; 
activityIndicator.frame=CGRectMake(140, 195, 37, 37); 
[activityIndicator startAnimating]; 

     SecondView *secView = [[SecondView alloc] initWithNibName:@"SecondView" bundle:nil]; 
     secView.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal; 

     UITableViewCell* cell = [tableView cellForRowAtIndexPath:indexPath]; 
     UILabel *name1 = (UILabel*)[cell viewWithTag:111]; 
     secView.provName = [name1 text]; 

     [self presentModalViewController: secView animated:NO]; 

     [secView release]; 
    } 

我在哪裏要去錯了嗎？

編輯：

SecondView：

-(void)viewWillAppear:(BOOL)animated 

{ 
    activityIndictr = [[UIActivityIndicatorView alloc]initWithFrame:CGRectMake(143, 220, 37, 37)]; 
    activityIndictr.activityIndicatorViewStyle = UIActivityIndicatorViewStyleGray; 

    activityIndictr.color = [UIColor redColor]; 
    [testscroll addSubview:activityIndictr]; 
    [activityIndictr startAnimating]; 

} 

-(void)viewDidLoad 
{ 
    [super viewDidLoad] 
    // I m calling many service urls(10) and assigning to labels and tableview 
    [activityIndictr stopAnimating]; 

} 

Answer 1

您分配活動指標，拋出的第一個客場，然後開始動畫的第二個兩次，絕不添加任何活動的指標爲任何現有的視圖。難怪它沒有出現。嘗試[[secView view] addSubview:activityIndicator]或類似的東西。

Answer 2

您應該調用SecondView的ViewWillAppear中的活動指示器，以便在推入此視圖後立即啓動活動指示器，然後在從url解析所有數據時將其解除。

這是因爲第二個視圖控制器就會立即推數據需要一定的時間來加載

Answer 3

在SecondView的viewWillAppear中做到這一點：

activityIndicator = [[UIActivityIndicatorView alloc]initWithFrame:CGRectMake(143, 220, 37, 37)]; 
activityIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyleGray; 
[self.view addSubview:activityIndicator]; 
[activityIndicator startAnimating]; 

Answer 4

我再次更新了答案。

把這個代碼的appdelegate而在的appdelegate定義靜態的物體，像下面

靜態UIActivityIndi​​catorView * activityView;

+(void)showActivityIndicator{ 

if (!activityView) { 
    activityView = [[UIActivityIndicatorView alloc]initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge]; 
    activityView.center = CGPointMake(160, 230); 
    [activityView startAnimating]; 
    UIWindow *win = [UIApplication sharedApplication].keyWindow; 
    [win addSubview:activityView]; 
} 
} 


+(void)removeActivityIndicator{ 
if ([activityView superview]) { 
    [activityView removeFromSuperview]; 
    activityView = nil; 
} 
} 






- (void) tableView:(UITableView *)tableView accessoryButtonTappedForRowWithIndexPath:(NSIndexPath *)indexPath 
{ 
UIWindow *window = [UIApplication sharedApplication].keyWindow; 

//global static activity indicator... you can access from any other view controlller 

[AppDelegate showActivityIndicator]; 

} 

並得到響應後

[AppDelegate removeActivityIndicator];