Remove or change color of frame around UIWebView document display?

问题

I'm using a UIWebView to display a variety of file types (so I can't use a specialized PDF viewer) embedded into my main view (so I can't use a modal document interaction controller). My main view has a background design that clashes with the light gray frame that appears around documents in the UIWebView. Does anyone know a way to remove that gray frame, make it transparent or change its color?

I'm familiar with and have used the techniques for changing the background color of the UIWebView to avoid a "color flash" while it loads, and for removing the top and bottom shadow that appear when "overscrolling" the web view, but I haven't seen anyone address this gray frame. (It only appears when displaying documents like .doc or .pdf, not when displaying HTML content.) I've hidden all the images that are subviews of the UIWebView's scroll view, so apparently this is coming from somewhere else.

回答1:

This question was written while iOS 4 was current, but in iOS 5 and later, simply setting the backgroundColor and opaque properties of the UIWebView will remove that gray frame:

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

回答2:

You can change WebView's background color by assigning its backgroundColor property:

myWebView.backgroundColor = [UIColor redColor]; // will make red bakground

If you want transparency use [UIColor clearColor] instead. But remember - by making your views tranparent you can worsen app's performance.

回答3:

Since this has been around for a while I'll just throw some ideas out there.

You may be able to utilize the stringByEvaluatingJavaScriptFromString: method of the UIWebView class to manipulate the document object model if the UIWebView treats the loaded document as a page, but this method has some limitations.

Other than that, the only thing you really have left at your disposal is manipulating the view hierarchy to modify any subviews of the UIWebView, but there may not be anything for you manipulate if the UIWebView class renders the viewer directly rather than creating a hierarchy.

回答4:

It looks like it is not possible to remove the border from a UIWebView but could you not use CGContextDrawPDFPage() as Apple show here: http://developer.apple.com/library/ios/#samplecode/ZoomingPDFViewer/Introduction/Intro.html

回答5:

Try this,

self.webview.backgroundColor = [UIColor whiteColor];

for (UIView* subView in [self.webview subviews])
{
    if ([subView isKindOfClass:[UIScrollView class]]) {
        for (UIView* shadowView in [subView subviews])
        {
            if ([shadowView isKindOfClass:[UIImageView class]]) {
                [shadowView setHidden:YES];
            }
        }
    }
}

This may help you. :-)

回答6:

You need a bunch of CoreAnimation magic:

- (void) hideShadowInLayer:(CALayer *) layer
{
    for (CALayer *l in layer.sublayers) {
        l.shadowOpacity = 0;
        [self hideShadowInLayer:l];
    }
}

- (void) hideShadows
{
    [CATransaction begin];
    [CATransaction setValue:(id) kCFBooleanTrue forKey:kCATransactionDisableActions];
    [self hideShadowInLayer:webView.layer];
    [CATransaction commit];
}

You need to perform hideShadows method somewhere AFTER loading your document and while you are scrolling it (I guess scrollViewDidScroll of webView.scrollView.delegate is a good place). You also need to include QuartzCore framework to your project.

What's going on here:

Any view uses something called layer for rendering. Layers can have its own hierarchy and every layer can have its own border and shadow, so the frame that annoying you is the shadow of one of them. Bad thing - UIWebView recreates it while scrolling - so you need to use this method constantly. And I guess shadowOpacity has a default animation attached to it, so you need CATransaction to disable it.

来源：https://stackoverflow.com/questions/7045769/remove-or-change-color-of-frame-around-uiwebview-document-display

标签

iphone

ios

uiwebview