UIWebView background is set to Clear Color, but it is not transparent

140
votes

I'm developing an iOS 4 application using iOS SDK latest version and XCode 4.2.

I have a XIB with a UIWebView with Alpha = 1.0, Background set to Clear Color and Opaque is not set. On this XIB I setup an image as background with this code:

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        UIColor *background = [[UIColor alloc] initWithPatternImage:[UIImage imageNamed:@"AboutBackground.png"]];
        self.view.backgroundColor = background;
        [background release];
    }
    return self;
}

The UIWebView is showing an static html:

<html><head></head><body style=\"margin:0 auto;text-align:center;background-color: transparent; color:white\">...</body></html>

On iOS 5 simulator, its background is transparent, but on an iOS 4 device is grey.

Any clue?

8
iphoneobjective-cioscocoa-touchuiwebview
try to just put an UIImageView on your webview in interface builder and set it your image. – Stas
Thanks for your answer, but the web view doesn't fill the entire screen. – VansFannel
possible duplicate of How to make a transparent UIWebVIew – Vladimir

8 Answers

363
votes

Also set :

[webView setBackgroundColor:[UIColor clearColor]];
[webView setOpaque:NO];
15
votes
     /*for ios please set this*/

     [webViewFirst setOpaque:NO];

     /*for html please set this*/
     <body style="background:none">
9
votes

Besides setting your webview's background to clear color, also make sure that you set opaque to false.

3
votes
webView.opaque = NO;

webView.backgroundColor = [UIColor clearColor];
3
votes

You can try this code (i know, that it's unsafe, but it works even for ios5): 

- (void)makeBodyBackgroundTransparent {
        for (UIView *subview in [webView subviews]) {
            [subview setOpaque:NO];
            [subview setBackgroundColor:[UIColor clearColor]];
        }
        [webView setOpaque:NO];
        [webView setBackgroundColor:[UIColor clearColor]];
}
3
votes
NSString *content=@"example clear background color UIWebview";
NSString *style=[NSString stringwithformat:@"<html><head><style>body {background-color:transparent;}</style></head><body>%@</body></html>",content];
[myWebview loadhtmlstring:style baseurl:nil];
1
votes

For Objective

webView.opaque = NO;
webView.backgroundColor = [UIColor clearColor];

Please make sure to include this into your HTML code:

<body style="background-color: transparent;">

or

 <body style="background:none">
1
votes

Latest Swift Version (as required):

lazy var webView: UIWebView = {
    let view = UIWebView()
    view.delegate = self
    view.backgroundColor = .clear
    view.isOpaque = false
    return view
}()

Remove delegate line if not required