如何在Windows应用商店应用中打印WebView内容？

Question

我有一个Metro应用程序,我正在尝试打印WebView控件的内容.使用MSDN Print Sample作为我的源参考.我简单地改变XAML中printableArea,如下所示:

    <RichTextBlock>
        <Paragraph>
            <InlineUIContainer>
                <WebView Width="800" Height="2000" Source="http://www.stackoverflow.com"/>
            </InlineUIContainer>
        </Paragraph>
    </RichTextBlock>

这部分起作用.问题是Visible指定尺寸的区域是Printed,即可以滚动的区域不打印,也不会在PrintPreview中显示为多页.

我几乎在那里,希望得到一些帮助,让它按预期工作.

我没有在任何地方找到任何样本,这解决了这个具体问题.

我甚至在这里尝试过这些解决方案:http://social.msdn.microsoft.com/Forums/en-US/winappswithcsharp/thread/5edcb239-7a5b-49f7-87e3-e5a253b809c4

我不是第一个遇到相同/类似问题的人:http: //social.msdn.microsoft.com/Search/en-US/？Refinement = 112&query = print%20webview #refinementChanges = 180&pageNumber = 1&showMore = false

愿意为能解决这个问题的人提供100分的赏金.非常感谢演练,示例代码或模拟项目作为解决方案.

Answer 1

喏,给你.

首先,您可以调整WebView实际内容的大小.然后,您将WebView后缩放到原始大小.它需要一个脚本调用和一个ScaleTransform.很简单,真的.

像这样:

<Grid Background="{StaticResource ApplicationPageBackgroundThemeBrush}">
    <WebView x:Name="MyWebView" Source="http://www.stackoverflow.com" />
</Grid>

void MyWebView_LoadCompleted(object sender, NavigationEventArgs e)
{
    var _Original = MyWebView.RenderSize;

    // ask the content its width
    var _WidthString = MyWebView.InvokeScript("eval",
        new[] { "document.body.scrollWidth.toString()" });
    int _Width;
    if (!int.TryParse(_WidthString, out _Width))
        throw new Exception(string.Format("failure/width:{0}", _WidthString));

    // ask the content its height
    var _HeightString = MyWebView.InvokeScript("eval",
        new[] { "document.body.scrollHeight.toString()" });
    int _Height;
    if (!int.TryParse(_HeightString, out _Height))
        throw new Exception(string.Format("failure/height:{0}", _HeightString));

    // resize the webview to the content
    MyWebView.Width = _Width;
    MyWebView.Height = _Height;

    // scale the webview back to original height (can't do both height & width)
    var _Transform = (MyWebView.RenderTransform as ScaleTransform)
        ?? (MyWebView.RenderTransform = new ScaleTransform()) as ScaleTransform;
    var _Scale = _Original.Height / _Height;
    _Transform.ScaleX = _Transform.ScaleY = _Scale;
}

这将导致一个非常高,WebView像这样的狭窄:

但那不是你想要的.

即使您可以调整生成的矩形的大小以使其不那么疯狂,但Windows 8中的"打印合同"要求您为其提供单个页面.它不会为你做分页.因此,您真正需要的是一次一页地检索单个网站.

第一种方法是如何做到这一点的基础.但是您需要将矩形的大小固定为Windows 8的"打印"任务传递给您的页面大小.这将基于用户的打印机选择.例如,Letter与A4(英国).然后,使用画笔的"拉伸"属性可以确保它自行裁剪.然后,使用画笔的"变换"属性,可以在矩形内部上下滑动,直到它显示您要打印的页面.

这是如何做:

<Grid Background="Blue">
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="995" />
        <ColumnDefinition Width="300" />
        <ColumnDefinition />
    </Grid.ColumnDefinitions>
    <WebView Grid.Column="0" x:Name="MyWebView" Source="http://www.stackoverflow.com" HorizontalAlignment="Right" />
    <Rectangle Grid.Column="1" x:Name="MyWebViewRectangle" Fill="Red" />
    <ScrollViewer Grid.Column="2" HorizontalScrollBarVisibility="Auto" VerticalScrollBarVisibility="Auto">
        <ItemsControl x:Name="MyPrintPages" VerticalAlignment="Top" HorizontalAlignment="Left">
            <Rectangle Height="150" Width="100" Fill="White" Margin="5" />
            <Rectangle Height="150" Width="100" Fill="White" Margin="5" />
            <Rectangle Height="150" Width="100" Fill="White" Margin="5" />
            <Rectangle Height="150" Width="100" Fill="White" Margin="5" />
            <Rectangle Height="150" Width="100" Fill="White" Margin="5" />
        </ItemsControl>
    </ScrollViewer>
</Grid>

public MainPage()
{
    this.InitializeComponent();
    MyWebView.LoadCompleted += MyWebView_LoadCompleted;
}

void MyWebView_LoadCompleted(object sender, NavigationEventArgs e)
{
    MyWebViewRectangle.Fill = GetWebViewBrush(MyWebView);
    MyPrintPages.ItemsSource = GetWebPages(MyWebView, new Windows.Foundation.Size(100d, 150d));
    MyWebView.Visibility = Windows.UI.Xaml.Visibility.Visible;
}

WebViewBrush GetWebViewBrush(WebView webView)
{
    // resize width to content
    var _OriginalWidth = webView.Width;
    var _WidthString = webView.InvokeScript("eval",
        new[] { "document.body.scrollWidth.toString()" });
    int _ContentWidth;
    if (!int.TryParse(_WidthString, out _ContentWidth))
        throw new Exception(string.Format("failure/width:{0}", _WidthString));
    webView.Width = _ContentWidth;

    // resize height to content
    var _OriginalHeight = webView.Height;
    var _HeightString = webView.InvokeScript("eval",
        new[] { "document.body.scrollHeight.toString()" });
    int _ContentHeight;
    if (!int.TryParse(_HeightString, out _ContentHeight))
        throw new Exception(string.Format("failure/height:{0}", _HeightString));
    webView.Height = _ContentHeight;

    // create brush
    var _OriginalVisibilty = webView.Visibility;
    webView.Visibility = Windows.UI.Xaml.Visibility.Visible;
    var _Brush = new WebViewBrush
    {
        SourceName = webView.Name,
        Stretch = Stretch.Uniform
    };
    _Brush.Redraw();

    // reset, return
    webView.Width = _OriginalWidth;
    webView.Height = _OriginalHeight;
    webView.Visibility = _OriginalVisibilty;
    return _Brush;
}

IEnumerable<FrameworkElement> GetWebPages(WebView webView, Windows.Foundation.Size page)
{
    // ask the content its width
    var _WidthString = webView.InvokeScript("eval",
        new[] { "document.body.scrollWidth.toString()" });
    int _ContentWidth;
    if (!int.TryParse(_WidthString, out _ContentWidth))
        throw new Exception(string.Format("failure/width:{0}", _WidthString));
    webView.Width = _ContentWidth;

    // ask the content its height
    var _HeightString = webView.InvokeScript("eval",
        new[] { "document.body.scrollHeight.toString()" });
    int _ContentHeight;
    if (!int.TryParse(_HeightString, out _ContentHeight))
        throw new Exception(string.Format("failure/height:{0}", _HeightString));
    webView.Height = _ContentHeight;

    // how many pages will there be?
    var _Scale = page.Width / _ContentWidth;
    var _ScaledHeight = (_ContentHeight * _Scale);
    var _PageCount = (double)_ScaledHeight / page.Height;
    _PageCount = _PageCount + ((_PageCount > (int)_PageCount) ? 1 : 0);

    // create the pages
    var _Pages = new List<Windows.UI.Xaml.Shapes.Rectangle>();
    for (int i = 0; i < (int)_PageCount; i++)
    {
        var _TranslateY = -page.Height * i;
        var _Page = new Windows.UI.Xaml.Shapes.Rectangle
        {
            Height = page.Height,
            Width = page.Width,
            Margin = new Thickness(5),
            Tag = new TranslateTransform { Y = _TranslateY },
        };
        _Page.Loaded += (s, e) =>
        {
            var _Rectangle = s as Windows.UI.Xaml.Shapes.Rectangle;
            var _Brush = GetWebViewBrush(webView);
            _Brush.Stretch = Stretch.UniformToFill;
            _Brush.AlignmentY = AlignmentY.Top;
            _Brush.Transform = _Rectangle.Tag as TranslateTransform;
            _Rectangle.Fill = _Brush;
        };
        _Pages.Add(_Page);
    }
    return _Pages;
}

因此UI将是这样的,其中左列是WebView,第二列(中间)是像我们的第一个解决方案一体化,第三列是转发器,显示准备打印的各个页面.

当然,神奇的是GetWebPages()方法!我不介意说,这是一个简单的奇迹,通过C#和Transforms的工作方式变得非常简单.

请注意,这还不完整.是的,它打破了你的页面,但我不能确定你想要在你的页面上多少边距.因此所需的调整很小,但我想提一下.这是分解WebView所需的98%的代码,如果是针对paginate事件的Windows 8打印任务,则需要准备.然后一次一个地将矩形传递给它.

话虽如此,这可能是互联网上这个问题最全面的解决方案.:)

祝你好运!