无法从完成处理程序进行网络调用？

Question

我正在尝试访问用户表单 phone.So 的联系人，或者我正在使用完成 handler.So 的目的，当应用程序尝试访问用户的联系人时，它会显示警告并请求权限允许 contacts.When 用户按下按钮 'OK'。

然后执行一个块，那时我创建网络 call.Although 函数被调用，但从未调用委托，也从未收到响应。

ABAddressBookRef addressBookRef = ABAddressBookCreateWithOptions(NULL, NULL);
    if (ABAddressBookGetAuthorizationStatus() == kABAuthorizationStatusNotDetermined)
    {

        ABAddressBookRequestAccessWithCompletion(addressBookRef, ^(bool granted, CFErrorRef error) {
            // First time access has been granted, add the contact
            NSLog(@"access contact");
           [self sample];

        });
          NSLog(@"after sccess contact");

    }
    else if (ABAddressBookGetAuthorizationStatus() == kABAuthorizationStatusAuthorized)
    {
        // The user has previously given access, add the contact
        NSLog(@"previous access");
    }
    else
    {
        // The user has previously denied access
        // Send an alert telling user to change privacy setting in settings app
        NSLog(@"send alert");
    }
    CFErrorRef error = NULL;

网络调用

-(void)sample
{
    NSLog(@"sample func called");
    // Create the request.
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://google.com"]];

    // Specify that it will be a POST request
    request.HTTPMethod = @"POST";

    // This is how we set header fields
    [request setValue:@"application/xml; charset=utf-8" forHTTPHeaderField:@"Content-Type"];

    // Convert your data and set your request's HTTPBody property
    NSString *stringData = @"some data";
    NSData *requestBodyData = [stringData dataUsingEncoding:NSUTF8StringEncoding];
    request.HTTPBody = requestBodyData;

    // Create url connection and fire request
    sampleConn= [[NSURLConnection alloc] initWithRequest:request delegate:self];
}

Answer 1

试试这个

替换您的代码

[self sample];

有

dispatch_async(dispatch_get_main_queue(), ^{

    [self sample];
});

无法从完成处理程序进行网络调用？

Unable to make network call from completion handler?

iphone

xcode

objective-c

ipad

ios