Question

以下代码冻结了我的UI。不能做任何行动。

- (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];
}

任何人都可以告诉我它的确切原因或任何替代方法来执行类似的继续轮询代码。

Answer 1

您正在创建一个无限循环：

longCall致电dataReceived来电longCall等......

Answer 2

你究竟想做什么。 longPool和dataReceived之间存在无限循环应该有一种机制，你可以停止这个电话，你可以使用

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

在IOS中冻结UI

2 个答案: