How to determine the content size of a UIWebView?

Question

I have a UIWebView with different (single page) content. I\'d like to find out the CGSize of the content to resize my parent views appropriately. T

Answer 1

I have another solution that works great.

On one hand, Ortwin's approach & solution works only with iOS 6.0 and later, but fails to work correctly on iOS 5.0, 5.1 and 5.1.1, and on the other hand there is something that I don't like and can't understand with Ortwin's approach, it's the use of the method [webView sizeThatFits:CGSizeZero] with the parameter CGSizeZero : If you read Apple Official documentation about this methods and its parameter, it says clearly :

The default implementation of this method returns the size portion of the view’s bounds rectangle. Subclasses can override this method to return a custom value based on the desired layout of any subviews. For example, a UISwitch object returns a fixed size value that represents the standard size of a switch view, and a UIImageView object returns the size of the image it is currently displaying.

What I mean is that it's like he came across his solution without any logic, because reading the documentation, the parameter passed to [webView sizeThatFits: ...] should at least have the desired width. With his solution, the desired width is set to the webView's frame before calling sizeThatFits with a CGSizeZero parameter. So I maintain this solution is working on iOS 6 by "chance".

I imagined a more rational approach, which has the advantage of working for iOS 5.0 and later... And also in complex situations where more than one webView (With its property webView.scrollView.scrollEnabled = NO is embedded in a scrollView.

Here is my code to force the Layout of the webView to the desired width and get the corresponding height set back to the webView itself:

Obj-C

- (void)webViewDidFinishLoad:(UIWebView *)aWebView
{   
    aWebView.scrollView.scrollEnabled = NO;    // Property available in iOS 5.0 and later 
    CGRect frame = aWebView.frame;

    frame.size.width = 200;       // Your desired width here.
    frame.size.height = 1;        // Set the height to a small one.

    aWebView.frame = frame;       // Set webView's Frame, forcing the Layout of its embedded scrollView with current Frame's constraints (Width set above).

    frame.size.height = aWebView.scrollView.contentSize.height;  // Get the corresponding height from the webView's embedded scrollView.

    aWebView.frame = frame;       // Set the scrollView contentHeight back to the frame itself.
}

Swift 4.x

func webViewDidFinishLoad(_ aWebView: UIWebView) {

    aWebView.scrollView.isScrollEnabled = false
    var frame = aWebView.frame

    frame.size.width = 200
    frame.size.height = 1

    aWebView.frame = frame
    frame.size.height = aWebView.scrollView.contentSize.height

    aWebView.frame = frame;
}

Note that in my example, the webView was embedded in a custom scrollView having other webViews... All these webViews had their webView.scrollView.scrollEnabled = NO, and the last piece of code I had to add was the calculation of the height of the contentSize of my custom scrollView embedding these webViews, but it was as easy as summing my webView's frame.size.height computed with the trick described above...