UIActivityIndi​​catorView冻结

Question

我有这个函数调用函数来检查CMS的信息。但是UIActivityIndi​​catorView冻结直到检查完成。不知道为什么。

编辑：有一件事很有趣，我评论了performselector。 UIActivityIndi​​catorView仍然冻结。直到我点击我的后退按钮然后开始旋转......

我正在使用故事板，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，并激活活动指示器。 尝试在延迟时添加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）与您的代码中的额外内容相关的代码，如：loading.alpha = 1;和blackOverlay.hidden = 0;我假设是添加到活动指标的元素