SVProgressHud等了太久才解雇

Question

我想在登录过程中显示SVProgressHUD。但是SVProgressHUD登录后仍然等待。它在"登录成功"消息后~15seconds关闭。这是我的代码：

[SVProgressHUD show];
__block BOOL result;
dispatch_async(queue, ^{
    result = [self autanticate];
    NSLog(@"autantication result = %d", result);
    result = [self getCSRFToken];
    NSLog(@"Login success result = %d", result);
    [SVProgressHUD dismiss];
});

autanticate和getCSRFToken函数如下所示：

- (BOOL) getCSRFToken
{
__block BOOL success = false;
AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
// Make sure that the callbacks are not called from the main queue, otherwise we would deadlock
manager.requestSerializer = [AFJSONRequestSerializer serializer];
manager.responseSerializer = [AFHTTPResponseSerializer  serializer];
NSDictionary *parameters = @{@"username": self.username.text,
                             @"password": self.password.text};
NSLog(@"Creating CSRF semaphore");
dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);
// CSRF Token bilgisini alalım
NSString *Url = [NSString stringWithFormat:@"%@%@", BaseURLString, @"?q=services/session/token"];
[manager GET:Url parameters:parameters success:^(AFHTTPRequestOperation *operation, id responseObject) {
    NSLog(@"CSRF Token: %@", responseObject);
    success = true;
    dispatch_semaphore_signal(semaphore);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
    NSLog(@"Error: %@", error);
    success = false;
    dispatch_semaphore_signal(semaphore);
}];
NSLog(@"Waiting CSRF semaphore");
dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);
return success;

}

- (BOOL)autanticate
{
__block BOOL isAutanticated = false; 
AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
manager.requestSerializer = [AFJSONRequestSerializer serializer];
manager.responseSerializer = [AFJSONResponseSerializer  serializer];
NSDictionary *parameters = @{@"username": self.username.text,
                             @"password": self.password.text};
// Session bilgilerini alalım
NSLog(@"Creating autantication semaphore");
dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);
NSString *Url = [NSString stringWithFormat:@"%@%@", BaseURLString, @"?q=rest/mserv/signin"];
[manager POST:Url parameters:parameters success:^(AFHTTPRequestOperation *operation, id responseObject) {
    NSLog(@"JSON: %@", responseObject);
    NSDictionary *result = [responseObject objectForKey:@"result"];
    NSString *sessid = [result objectForKey:@"sessid"];
    NSString *session_name = [result objectForKey:@"session_name"];
    NSLog(@"sessid = %@nsession_name=%@", sessid, session_name);
    isAutanticated = true;
    dispatch_semaphore_signal(semaphore);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
    NSLog(@"Error: %@", error);
    isAutanticated = false;
    dispatch_semaphore_signal(semaphore);
}];
NSLog(@"Waiting autanticatio semaphore");
dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);
return isAutanticated;
}

Answer 1

您必须将

[SVProgressHUD dismiss]分派给主线程

[SVProgressHUD show];
__block BOOL result;
dispatch_async(queue, ^{
    result = [self autanticate];
    NSLog(@"autantication result = %d", result);
    result = [self getCSRFToken];
    NSLog(@"Login success result = %d", result);
    dispatch_async(dispatch_get_main_queue(), ^{
        [SVProgressHUD dismiss];
    })
});

只能在主线程上修改所有用户界面元素。

备注：请注意，dispatch_async()返回（几乎）立即，这样就不会设置result当dispatch_async()回来时。并且不要试图使用信号量来等待块完成。这在后台线程上很好，但很可能会造成死锁在主线程上。