Iphone 在IOS中冻结UI

下面的代码正在冻结我的UI。不能做任何动作

- (void) longPoll {
    //create an autorelease pool for the thread
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

        NSError* error = nil;
        NSURLResponse* response = nil;
        NSURL* requestUrl = [NSURL URLWithString:@"myurl"];
        NSURLRequest* request = [NSURLRequest requestWithURL:requestUrl];

        //send the request (will block until a response comes back)
        NSData* responseData = [NSURLConnection sendSynchronousRequest:request
                                                     returningResponse:&response error:&error];
        dispatch_async(dispatch_get_main_queue(), ^{
            [self dataReceived:responseData];
        });
    });
        //compose the request


        //pass the response on to the handler (can also check for errors here, if you want)


        //clear the pool

    }




- (void) startPoll {
    //not covered in this example:  stopping the poll or ensuring that only 1 poll is active at any given time
    [self performSelectorInBackground:@selector(longPoll) withObject: nil];
}

- (void) dataReceived: (NSData*) theData {
    //process the response here
    NSDictionary *dict=[theData JSONValue];
   [self ParseJson:dict];
     [self performSelectorInBackground:@selector(longPoll) withObject: nil];
}

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有人能告诉我它的确切原因吗？或者有没有其他方法可以使用类似的代码继续轮询。

您正在创建一个无限循环：

---

longCall

calls

dataReceived

calls

longCall

等……

您到底想做什么。在longPool和dataReceived之间存在无限循环 应该有一个机制，你可以停止这个电话，你可以使用它

@autorelease {} block for create autorelease pool in ARC Enabled project and
NSAutoReleasePool class obj for Without ARC.

---

无需调用

dataReceived:

在

dispatch\u async（dispatch\u get\u main\u queue（），^{

检查您在[self-ParseJson:dict]中执行的操作；只有它可以冻结UI。