iPhone: Add "loading" subView

Question

I am wanting to show a simple loading dialog when certain things are happening in my app. I figured I would just create a new view, add a label to that, and then set that view to a subView of my current view.

When doing this, I don't see anything!

Here is how I am writing my method:

- (void)showLoading {
    UIView *loading = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 200, 200)];
    loading.backgroundColor = [UIColor blackColor];
    UILabel *txt = [[UILabel alloc] initWithFrame:CGRectMake(198, 9, 94, 27)];
    txt.text = @"Loading...";
    txt.textColor = [UIColor whiteColor];
    [loading addSubview:txt];
    [super.view addSubview:loading];
    [super.view bringSubviewToFront:loading];
    [loading release];
    [txt release];
}

Am I doing this completely wrong?

EDIT: I added it to the viewDidLoad method, and it works how I want:

loading = [[UIView alloc] initWithFrame:CGRectMake(100, 100, 200, 200)];
    loading.backgroundColor = [UIColor blackColor];
    UILabel *txt = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 94, 27)];
    txt.text = @"Loading...";
    txt.textColor = [UIColor whiteColor];
    [loading addSubview:txt];
    [txt release];
    [self.view addSubview:loading];
    [self.view bringSubviewToFront:loading];

But when loading it from a method, it seems to lag, and not show up for a bit.

Answer 1

First, I don't think UIView has method called init. You may just call the super of it. The appropriate method you should call is - (id)initWithFrame:(CGRect)aRect . The frame is the position, the size of the View you want to display. More here

Another thing is why you call [super.view addSubView:], I think it should be self.view, isn't it?

Answer 2

Although this doesn't directly answer your question, I'd recommend grabbing MBProgressHUD from GitHub and using that in place of a static label. Looks better, less code for you to directly maintain, etc. You can find it at http://github.com/matej/MBProgressHUD

The way I use it is by creating a subclass of UITableViewController and defining a handful of methods to show and hide the HUD view. From there, I call each relevant method when I'm loading or done loading.

Specifically, I have four methods: -hudView, -showLoadingUI, -showLoadingUIWithText:, and -hideLoadingUI.

-hudView creates a new MBProgressHUD object if one doesn't already exist, and adds it to the current view ([self.view addSubview:hudView]).

-showLoadingUI calls -showLoadingUIWithText: with a default title, -showLoadingUIWithText: just unhides the MBProgressHUD and sets a label value for it (self.hudView.labelText = @"foo";).

-hideLoadingUI hides the hudView ([self.hudView hide:YES]).