objective-c - 新しいスレッドで読み込んでいます

Question

Web サービスを呼び出している間、読み込み中のビューを実行しようとしています... 私はこれを試しました:

-(void) viewDidLoad {
[NSThread detachNewThreadSelector:@selector(workerThread) toTarget:self withObject:nil];
//here I call the thread before call web service
 }


 -(void) workerThread {
[viewLoading setHidden:NO];
[NSThread detachNewThreadSelector:@selector(threadAnimacao) toTarget:self withObject:nil];
}


 -(void) threadAnimacao { //call this function is ok, but the timerLoadingEvento only is called after the call webservice ends
contadorLoading = 0;
nVoltas = 0;
nEspera = 0;
timerLoading = [NSTimer scheduledTimerWithTimeInterval:0.5 target:self selector:@selector(timerLoadingEvento:) userInfo:nil repeats:YES]; 
}


-(void)timerLoadingEvento:(NSTimer *)theTimer{
UIImageView *img = imgLoading;

if (nEspera == 0) {
    if(contadorLoading == 0)
        [img setImage:[UIImage imageNamed:@"frame_01.png"]];
    else if(contadorLoading == 1)
        [img setImage:[UIImage imageNamed:@"frame_02.png"]];
    else if(contadorLoading == 2)
        [img setImage:[UIImage imageNamed:@"frame_03.png"]];
    else if(contadorLoading == 3)
        [img setImage:[UIImage imageNamed:@"frame_04.png"]];
    else if(contadorLoading == 4)
        [img setImage:[UIImage imageNamed:@"frame_05.png"]];
    else if(contadorLoading == 5)
        [img setImage:[UIImage imageNamed:@"frame_06.png"]];
    else if(contadorLoading == 6)
        [img setImage:[UIImage imageNamed:@"frame_07.png"]];
    else if(contadorLoading == 7)
        [img setImage:[UIImage imageNamed:@"frame_08.png"]];
    else if(contadorLoading == 8)
        [img setImage:[UIImage imageNamed:@"frame_09.png"]];
}

contadorLoading++;
nVoltas++;

if(nEspera != 0)
    nEspera++;

if(nEspera>250) {
    nEspera = 0;
    contadorLoading = 0;
    nVoltas = 0;
}

if(contadorLoading == 8)
    contadorLoading = 0;

if(nVoltas == 9)
    nEspera = 1;
 }