objective c - UIWebView dones't resize correctly when orientation change?

Question

I have add a webview,a titleLabel and a coverflowView on a viewcontroller's view as its subviews, I want it to change size when the orientation change. I have change the webview's frame in this method:

 - (void)willRotateToInterfaceOrientation: (UIInterfaceOrientation)toInterfaceOrientation duration: (NSTimeInterval)duration 

its content did resize when rotate iPad from orientationLandscape to orientationPortrait or from orientationPortrait to orientationLandscape if I start the application with portrait orientation, but it is so strange that its content dosen't resize when I start the application with landscape orientation...But the NSLog shows the frame has changed. As to the titleLabel and the coverflowView, they resize correctly. I doubt if it is because of css?I have use css to control the content's style according to the height and width of webview.Does anyone could help me to find the reason? the code is below:

- (void)willRotateToInterfaceOrientation: (UIInterfaceOrientation)toInterfaceOrientation duration: (NSTimeInterval)duration {
double i = 0;
NSInteger  width=self.view.frame.size.width;
NSInteger  height=self.view.frame.size.height;
NSLog(@"view :%@",[self.view description]);
switch (toInterfaceOrientation){
    case UIInterfaceOrientationPortrait:
    {    
        NSLog(@"rotate to Portrait");
        if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad){
            self.docView.frame=CGRectMake(0, 50, width+20, height-70);
            self.toolbar.frame=CGRectMake(0, 0,height , 50);
            for (UIView * view in [toolbar subviews]) {
                if ([view isKindOfClass:[UIButton class]] && view.tag==kBackButtonTag){
                    view.frame=CGRectMake(width-60, 6, 50, 36);

                }else if([view isKindOfClass:[UIButton class]] && view.tag==kReloadButtonTag){
                    view.frame=CGRectMake(width-160, 6, 80,36 );
                }
            }
            [coverflow setFrame:CGRectMake(0, 0 , width+20, height/2-50)];
            [titleLabel setFrame:CGRectMake(width/2-40,height/2-100, 100, 20)];
            if ([[[UIDevice currentDevice]model]isEqualToString:@"iPad"]) {
                self.viewer.frame=CGRectMake(0, 0, 768, 1004);
            }else{
                self.viewer.frame=CGRectMake(0, 0, 320, 480);
            }
        }
        i=0;
    }break;
    case UIInterfaceOrientationPortraitUpsideDown:
    {
        NSLog(@"rotate to PortraitUpsideDown");
        if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad){
            self.docView.frame=CGRectMake(0, 50, width+20, height-70);
            self.toolbar.frame=CGRectMake(0, 0,height , 50);
            for (UIView * view in [toolbar subviews]) {
                if ([view isKindOfClass:[UIButton class]] && view.tag==kBackButtonTag)  {
                    view.frame=CGRectMake(width-60, 6, 50, 36);

                }else if([view isKindOfClass:[UIButton class]] && view.tag==kReloadButtonTag){
                    view.frame=CGRectMake(width-160, 6, 80,36 );
                }
            }

            [coverflow setFrame:CGRectMake(0, 0 , width+20, height/2-50)];
            [titleLabel setFrame:CGRectMake(width/2-40,height/2-100, 100, 20)];
            if ([[[UIDevice currentDevice]model]isEqualToString:@"iPad"]) {
                self.viewer.frame=CGRectMake(0, 0, 768, 1004);
            }else{
                self.viewer.frame=CGRectMake(0, 0, 320, 480);
            }

        }

        i=180;
    }   break;
    case UIInterfaceOrientationLandscapeLeft:{

        NSLog(@"rotate to LandscapeLeft");
        if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad){
       //     self.coverflow.frame=CGRectMake(0, 0, height+20, width-20);
            self.docView.frame=CGRectMake(0, 50, height+20, width-70);
            self.toolbar.frame=CGRectMake(0, 0,height+20 , 50);
            for (UIView * view in [toolbar subviews]) {
                if ([view isKindOfClass:[UIButton class]] && view.tag==kBackButtonTag)  {
                    view.frame=CGRectMake(height-60, 6, 50, 36);
                    NSLog(@"button %@",[view description]);
                }else if([view isKindOfClass:[UIButton class]] && view.tag==kReloadButtonTag){
                    view.frame=CGRectMake(height-160, 6, 80,36 );
                }
            }
            [coverflow setFrame:CGRectMake(0, 0 , height+20, width/2-50)];
            [titleLabel setFrame:CGRectMake(height/2-40,width/2-80, 100, 20)];
            if ([[[UIDevice currentDevice]model]isEqualToString:@"iPad"]) {
                self.viewer.frame=CGRectMake(0, 0, 1024, 748);
            }else{
                self.viewer.frame=CGRectMake(0, 0, 480, 320);
            }
        }

        i = 90;
    }break;
    case UIInterfaceOrientationLandscapeRight:{
        NSLog(@"rotate to LandscapeRight");
        if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad){
        //    self.coverflow.frame=CGRectMake(0, 0, height+20, width-20);
            self.docView.frame=CGRectMake(0, 50, height+20, width-70);
            self.toolbar.frame=CGRectMake(0, 0,height+20 , 50);
            for (UIView * view in [toolbar subviews]) {
                if ([view isKindOfClass:[UIButton class]] && view.tag==kBackButtonTag)  {
                    view.frame=CGRectMake(height-60, 6, 50, 36);
                }
                else if([view isKindOfClass:[UIButton class]] && view.tag==kReloadButtonTag){
                    view.frame=CGRectMake(height-160, 6, 80,36 );
                }
            }
            [coverflow setFrame:CGRectMake(0, 0 , height+20, width/2-50)];
            [titleLabel setFrame:CGRectMake(height/2-40,width/2-80, 100, 20)];
            if ([[[UIDevice currentDevice]model]isEqualToString:@"iPad"]) {
                self.viewer.frame=CGRectMake(0, 0, 1024, 748);
            }else{
                self.viewer.frame=CGRectMake(0, 0, 480, 320);
            }
        }

        i = -90;
    }break;
}

//[webViewController willRotateToInterfaceOrientation:toInterfaceOrientation duration:duration];
// [self.view setNeedsDisplay];
//   NSLog(@"coverflowView :%@",[self.coverflow description]);
   NSLog(@"webview :%@",[viewer description]);
    [viewer stringByEvaluatingJavaScriptFromString:[NSString stringWithFormat:@"window.__defineGetter__('orientation',function(){return %f;});",i]];
    [viewer stringByEvaluatingJavaScriptFromString:@"var e = document.createEvent('Events'); e.initEvent('orientationchange', true, false); document.dispatchEvent(e); "];    
}




- (void)viewDidLoad {
self.view.clipsToBounds=YES;
self.view.autoresizesSubviews=YES;
// self.view.autoresizingMask=UIViewAutoresizingNone;

viewer=[[UIWebView alloc]initWithFrame:self.view.bounds];

[self.view addSubview:viewer];
 viewer.delegate=self;
 viewer.scalesPageToFit=NO;
 viewer.autoresizesSubviews=NO;
 viewer.autoresizingMask=UIViewAutoresizingNone;
viewer.dataDetectorTypes=0;
// viewer.autoresizingMask=UIViewAutoresizingFlexibleWidth |UIViewAutoresizingFlexibleHeight;
NSLog(@"webView :%@",[viewer description]);
//  [viewer setFrame:CGRectMake(0, self.view.bounds.size.height/2 , self.view.bounds.size.width, self.view.bounds.size.height/2)];
//  [viewer setBounds:CGRectMake(0, self.view.bounds.size.height/2 , self.view.bounds.size.width, self.view.bounds.size.height/2)];

UIScrollView *scroller=[viewer.subviews objectAtIndex: 0];
if (scroller) {
    scroller.alwaysBounceVertical=NO;
    scroller.bounces=NO;
    scroller.scrollEnabled=NO;   
}

[self viewHomePage];
//[self createCoverFlowView];
[self createPopView];
//[self setHomeButtonPosition]; 
//[self setSettingButtonPosition];

#if __IPHONE_OS_VERSION_MIN_REQUIRED > 30000
UILongPressGestureRecognizer* longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLongPress:)];
[self.view addGestureRecognizer:longPress];
longPress.minimumPressDuration=2.0;
longPress.delegate = self;
longPress.cancelsTouchesInView = NO;
longPress.allowableMovement=20;
[longPress release];  

UITapGestureRecognizer* singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleSingleTap:)];
[self.view addGestureRecognizer:singleTap];
singleTap.delegate = self;
singleTap.cancelsTouchesInView = NO;
[singleTap release];  
#endif
//[viewer setOpaque:YES];      //透明
[super viewDidLoad];

}

Answer 1

I spent about two days trying to track this problem down, as I was having the exact same issue. I found that my view if it started off in Portrait mode would correctly resize to Landscape. But, if I started the view in Landscape mode, it would keep the same size in Portrait.

If your view is the entire width of the device, just adding the following meta tag will work.

<meta name="viewport" content="width=device-width" />

But, in my case, our UIWebView is a nonstandard size. Setting the viewport to device-width just makes it worse! I was able to have everything work out correctly by setting the viewport dynamically using javascript. This should be done during the UIWebViews parent view's layoutSubviews. You can do it in the willRotateToInterfaceOrientation, but I found out if you do in willRotate some of the sizes and interfaces might not be setup correctly. Try it there first and see how the animation works.

The code just sets the viewport size to the current frame size. The HTML you are viewing must have a meta viewport tag already (as above). If you can't edit the HTML, there are other ways of adding it via javascript. The easiest is to just add in the meta tag into the <head> tag. Then use the following code, AFTER you have set the frame correctly:

 // assuming your self.viewer is a UIWebView
[self.viewer stringByEvaluatingJavaScriptFromString:
     [NSString stringWithFormat:
     @"document.querySelector('meta[name=viewport]').setAttribute('content', 'width=%d;', false); ",
      (int)self.viewer.frame.size.width]];

You can add in other viewport items if you don't want the user to scale, or you want to set the max scale. This ended up making the view behave correctly for our UIWebView.