MBProgressHUD is not showing sometime in iOS

Question

I am using MBProgressHUD Custom Control to show when loading JSON Data from web.

I have already find a lot of answer that doesn't show correctly HUD Control in their View.

Here is my code to show HUD in my View.

[MBProgressHUD showHUDAddedTo:self.view animated:YES];

and Here is how i hide my HUD View.

[MBProgressHUD hideHUDForView:self.view animated:YES];

In ViewDidLoad , that control is working fine.

But when i click to refresh button and want to show HUD control , it doesn't show HUD Control.

[MBProgressHUD showHUDAddedTo:self.view animated:YES];

dispatch_queue_t myqueue = dispatch_queue_create("queue", NULL);
dispatch_async(myqueue, ^{

    [self performSelectorOnMainThread:@selector(fetchedData:) withObject:nil waitUntilDone:YES];

    dispatch_async(dispatch_get_main_queue(), ^{
        [self.tbl reloadData];
        [MBProgressHUD hideHUDForView:self.view animated:YES];
    });
});

I don't know what am I doing wrong? Please help me.

Even though you do a bunch of dispatching, all your work is ending up on the main queue! That will block the UI and the HUD won't show. — Jack, Feb 19 '14 at 16:28
Try calling fetchedData: directly instead of performing on the main thread and see if everything still works — Jack, Feb 19 '14 at 16:42

score 9 · Accepted Answer · answered Feb 19 '14 at 16:42

Switch your code to this:

[MBProgressHUD showHUDAddedTo:self.view animated:YES];

dispatch_queue_t myqueue = dispatch_queue_create("queue", NULL);
dispatch_async(myqueue, ^{

    //Whatever is happening in the fetchedData method will now happen in the background
    [self fetchedData:nil];

    dispatch_async(dispatch_get_main_queue(), ^{
        [self.tbl reloadData];
        [MBProgressHUD hideHUDForView:self.view animated:YES];
    });
});

You don't want to call the fetchData method on the main thread. If you use the code above, nothing in the fetchedData method will happen on the main thread, so make sure you don't update the UI or anything in there.

Just a suggestion, I wouldn't use the name "queue" for your dispatch_queue. The names of the queues across the app need to be unique, so I'd call it something like "your.bundle.id.viewcontrollername" just to avoid issues later.

MBProgressHUD is not showing sometime in iOS

1 Answers1