XCode Change Background Image with Orientation Change

Question

I have an iPhone app made up of a single UIWebView that displays a website. I have set a background image to the UIWebView after it finishes loading within my ViewController.m file, as shown here:

- (void)webViewDidFinishLoad:(UIWebView *)webView {
     // Set UIWebView Background Image
     self->webView.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"ui-background-portrait.png"]];
}

This is fine when the device is in Portrait orientation, but I would like to change the background image if the user switches the device orientation to landscape, and back to portrait if they switch again, etc.

I wrote the code below, but I'm not sure where to put it (as it needs to change the background image whenever they switch orientations; not just one time):

- (void)webViewDidFinishLoad:(UIWebView *)webView {
    // Set UIWebView Background Image
    if (UIDeviceOrientationIsPortrait([UIDevice currentDevice].orientation))
    {
        // code for Portrait orientation  
        self->webView.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"ui-background-portrait.png"]];
    }
    if (UIDeviceOrientationIsLandscape([UIDevice currentDevice].orientation))
    {
        // code for landscape orientation  
        self->webView.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"ui-background-landscape.png"]];
    }
}

How can I accomplish this? And if you could give me code and indicate where to put it, that would be such a great help :)

Answer 1

Override one of these methods in your view controller and put your code there.

– willRotateToInterfaceOrientation:duration:

– willAnimateRotationToInterfaceOrientation:duration:

– didRotateFromInterfaceOrientation:

Put this code in your ViewController.m

- (void) didRotateFromInterfaceOrientation:(UIInterfaceOrientation) fromInterfaceOrientation
{
    // Set UIWebView Background Image
    if (UIDeviceOrientationIsPortrait([UIDevice currentDevice].orientation))
    {
        // code for Portrait orientation  
        self->webView.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"ui-background-portrait.png"]];
    }
    if (UIDeviceOrientationIsLandscape([UIDevice currentDevice].orientation))
    {
        // code for landscape orientation  
        self->webView.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"ui-background-landscape.png"]];
    }
}