Question

I am fairly new to XCode – I’m designing an app with a single view that just displays a UIWebView that loads my jQuery mobile web site.

I have the Default.png and [e-mail] files for the Launch images in place. When I run the app on my test device or in the emulator, it shows my Launch Image, and then flashes a white screen while the UIWebView loads the first page.

I know that I can change the background color and opacity so it will flash a different color than white, but I would like to prevent the flash altogether. I would like the app to launch, show the Launch image, and not show the UIWebView until the first page has completely loaded. Help?

Answer 1

@ Andreas Volz (and anyone else wondering how I solved the problem of the white “flash”)

First, add the name-of-loading-image.png and [e-mail] files to your Xcode project. The regular image should be 320 x 460, and the @2x image should be 640 x 920.

Then, in my ViewController.h file I added these properties:

@property (nonatomic, retain) UIWebView *webView;
@property(nonatomic, strong) UIImageView *loadingImageView;
@end

And then in my ViewController.m file I added this:

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController;

@synthesize webView;
@synthesize loadingImageView;

- (void)viewDidLoad
{
    [super viewDidLoad];


    //**************** Set website URL for UIWebView
    [webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.example.com"] cachePolicy:NSURLCacheStorageAllowed timeoutInterval:20.0]];


    //**************** Add Static loading image to prevent white "flash" ****************/  
    UIImage *loadingImage = [UIImage imageNamed:@"name-of-loading-image.png"];
    loadingImageView = [[UIImageView alloc] initWithImage:loadingImage];
        loadingImageView.animationImages = [NSArray arrayWithObjects:
                                            [UIImage imageNamed:@"name-of-loading-image.png"],
                                            nil];
    [self.view addSubview:loadingImageView];   

}

- (void)webViewDidFinishLoad:(UIWebView *)webView {

    // Remove loading image from view
    [loadingImageView removeFromSuperview];

}