iphone - UIActivityIndi​​catorView 卡住

Question

我有这个函数，它调用一个函数来检查 CMS 的信息。但 UIActivityIndi​​catorView 卡住直到检查完成。不知道为什么。

编辑:有趣的是，我注释掉了 performselector。 UIActivityIndi​​catorView 仍然卡住。直到我点击后退按钮然后它开始旋转....

我正在使用 Storyboard，iOS 5

-(void)showLoading
{
    [activity startAnimating];
    //loading is a label to show "File Loading"
    loading.alpha =1;
    //is a label to show a 0.3 alpha of the label
    blackOverlay.hidden =0;
    [self performSelector:@selector(updateFromInternet:) withObject:@"a" afterDelay:2];  

    //[self updateFromInternet:@"a"];
}

-(void)updateFromInternet:(NSString *)urlStr

{   

    NSString *URLString = @"http://sites.google.com/site/iphonesdktutorials/xml/Books.xml";
    NSURL *updateDataURL = [NSURL URLWithString:URLString];    

    NSMutableURLRequest *WPXMLFetchRequest = [NSMutableURLRequest requestWithURL:updateDataURL];

    self.receivedData = [NSMutableData data];
    self.updateConnection = [NSURLConnection connectionWithRequest:WPXMLFetchRequest delegate:self];

    NSLog(@"Checking update at : %@", updateDataURL);

    //[self.updateConnection cancel];
}



-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
    ////NSlog(@"Receiving data");
    [self.receivedData appendData:data];
}

-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
    ////NSlog(@"Failed to receive data");
    self.receivedData = nil;
}

-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
    ////NSlog(@"Received response from data");
    [self.receivedData setLength:0];
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {

    NSString *data=[[NSString alloc]initWithData:self.receivedData encoding:NSUTF8StringEncoding];
    NSLog(@"data %@",data);

    NSError *parseError = nil;
    //NSDictionary *xmlDict = [XMLReader dictionaryForXMLData:self.receivedData error:&parseError];
    self.receivedDict = [XMLReader dictionaryForXMLData:self.receivedData error:&parseError];

    [self showDataOnScrollView];
}

Answer 1

您应该稍微延迟“重”功能并让事件指示器触发。 尝试为您的延迟添加 2.0 而不是 2(我会使用更小的值 - 比如 0.3)

[self performSelector:@selector(updateFromInternet:) withObject:@"a" afterDelay:0.3]; 

如果这不能解决您的问题，您应该查看(或发布)与代码中的额外内容相关的代码，例如:loading.alpha =1;和 blackOverlay.hidden =0;我假设是添加到事件指示器中的元素