Question

我有一堆静态html内容的webview，我将其作为页面放在滚动视图中。这工作正常，但有20个滚动视图的全屏子视图导致一些滞后。我只在那里一次放置5个就解决了这个问题。当前视图，以及前两个和前两个。

现在的问题是，任何不是滚动视图子视图的Web视图都无法根据设备方向正确绘制。 webview的框架打印正确，但实际内容是以纵向模式绘制的。因此，内容右侧基本上有一条空白区域。

如何在不重新加载页面的情况下重新呈现内容？

以下是相关代码：

- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation) fromInterfaceOrientation{
    [self resizeSubViews];
}


- (void) setupWebViews{

    if(_webViews == nil)
        _webViews = [[NSMutableArray alloc] init];

    // This is where the navigation would come into play as far as loading up available web views
    [_webViews removeAllObjects];

    // for loop here to create web views
    for (int i = 0; i < 20; i++) {

        //CDCWebViewController *webView = [[[MyInternalWebView alloc] initWithFrame:_webViewWrapper.frame] retain];

        MyInternalWebView *page = [[[MyInternalWebView alloc] init] retain];


        [page loadRequest:[NSURLRequest requestWithURL:_url]];
        [page setCdcIWVdelegate:self];

        [page setTestIndex:i];
        [page setPageIndex:i];

        [_webViews addObject:page];

        [self loadScrollViewWithPage:i];
    }

    [self clearUnusedWebViews:_pageControl.currentPage];
}

- (void) setupWebViewWrapper{

    // a page is the width of the scroll view
    _webViewWrapper.pagingEnabled = YES;

    _pageControl = [[[UIPageControl alloc] init] retain];

    _webViewWrapper.showsHorizontalScrollIndicator = NO;
    _webViewWrapper.showsVerticalScrollIndicator = NO;
    _webViewWrapper.scrollsToTop = NO;
    _webViewWrapper.delegate = self;

    _pageControl.numberOfPages = [_webViews count];
    _pageControl.currentPage = 0;

}

- (void) resizeSubViews{

    // The frame is set in IB
    _webViewWrapper.contentSize = CGSizeMake(_webViewWrapper.frame.size.width * [_webViews count], _webViewWrapper.frame.size.height);

    // Move the content offset.
    _webViewWrapper.contentOffset = CGPointMake(_webViewWrapper.frame.size.width * _pageControl.currentPage, _webViewWrapper.contentOffset.y);

    for (MyInternalWebView *subview in _webViewWrapper.subviews) {
        // Reset the frame height and width here?
        CGRect frame = _webViewWrapper.frame;
        frame.origin.x = frame.size.width * subview.pageIndex;
        frame.origin.y = 0;
        [subview setFrame:frame];
    }

}



//*****************************************************
//*
//*         ScrollView Functions
//*
//*****************************************************

- (void)loadScrollViewWithPage:(int)page {

    // Make sure we're not out of bounds
    if (page < 0) return;
    if (page >= [_webViews count]) return;

    MyInternalWebView *webView = [_webViews objectAtIndex:page];

    // Add the preloaded webview to the scrollview if it's not there already
    if (nil == [webView superview]) {
        CGRect frame = _webViewWrapper.frame;

        //NSLog(@"width = %f", frame.size.width);

        frame.origin.x = frame.size.width * page;
        frame.origin.y = 0;

        //NSLog(@"setting frame for page %d %@", page, NSStringFromCGRect(frame));

        [webView setFrame:frame];
        [_webViewWrapper addSubview:[_webViews objectAtIndex:page]];

        // Now that the new one is loaded, clear what doesn't need to be here
        [self clearUnusedWebViews:page];
    }


}

- (void) clearUnusedWebViews: (NSInteger) page{

    for (int i = 0; i < [_webViews count]; i++) {

        if ((page - i) <= 2 && i - page <= 2) {
            continue;
        }

        [[_webViews objectAtIndex:i] removeFromSuperview];
    }

}



- (void)scrollViewDidScroll:(UIScrollView *)sender {

    // Switch the indicator when more than 50% of the previous/next page is visible
    CGFloat pageWidth = _webViewWrapper.frame.size.width;
    NSInteger page = floor((_webViewWrapper.contentOffset.x - pageWidth / 2) / pageWidth) + 1;
    _pageControl.currentPage = page;

    // load the visible page and the page on either side of it (to avoid flashes when the user starts scrolling)
    [self loadScrollViewWithPage:page - 2];
    [self loadScrollViewWithPage:page - 1];
    [self loadScrollViewWithPage:page];
    [self loadScrollViewWithPage:page + 1];
    [self loadScrollViewWithPage:page + 2];

}

Answer 1

重载

重新加载当前页面。
- (void)reload
状况

适用于iOS 2.0及更高版本。

另见
  @property request
  @property loading
– loadRequest:
– stopLoading
声明

UIWebView.h

UIWebView Class Reference

Answer 2

在resizeSubViews中，从_webViews数组更改Web视图的帧，而不是滚动视图子视图。

附录：

如果页面！= _pageControl.currentPage，则检查scrollViewDidScroll，然后加载scrollViewsWithPage。
方向更改可能会触发scrollViewDidScroll。
在clearUnusedWebViews中使用_pageControl.currentPage而不是页面变量。当你在第5个视图并且你正在加载第7个时，你将删除第4个和第3个，甚至我说你的意图是在这个时候滚动视图中有3,4,5,6,7。

重绘UIWebView的内容

2 个答案:

重载

状况

另见