使用windows-community-toolkit打印助手扩展的分页符

Question

我正在使用windows-community-toolkit的PrintHelper扩展并打印一些数据。问题是，当数据很大时，它会与页面重叠，而我找不到一种方法来动态添加新页面并将数据转移到下一页面。有什么办法吗？

public PrintHelper PrintHelper;

public void StartPrint(Panel container, List<CompanyDetail> PrintSampleItems)
{
    try
    {
        PrintHelper = new PrintHelper(container);
        PrintHelper.OnPrintSucceeded += PrintHelper_OnPrintSucceeded;
        PrintHelper.OnPrintFailed += PrintHelper_OnPrintFailed;
        PrintHelper.OnPreviewPagesCreated += PrintHelperOnOnPreviewPagesCreated;
        var pageNumber = 0;

        var data = PrintSampleItems;

        var grid = new Grid();
        grid.RowDefinitions.Add(new RowDefinition() {Height = GridLength.Auto});
        grid.RowDefinitions.Add(new RowDefinition() {Height = new GridLength(1, GridUnitType.Star)});
        grid.RowDefinitions.Add(new RowDefinition() {Height = GridLength.Auto});

        // Static header
        var header = new TextBlock
        {
            Text = "Departments Print",
            Margin = new Thickness(0, 0, 0, 20),
            HorizontalAlignment = HorizontalAlignment.Center,
            FontSize = 18,
            FontWeight = FontWeights.Bold
        };
        Grid.SetRow(header, 0);
        grid.Children.Add(header);

        var dataGrid = new CompanyDetailReportTemplateControl
        {
            HorizontalAlignment = HorizontalAlignment.Center
        };
        dataGrid.SetValues(PrintSampleItems);

        Grid.SetRow(dataGrid, 1);
        grid.Children.Add(dataGrid);


        // Footer with page number
        pageNumber++;
        var footer = new TextBlock
        {
            Text = $"Page [ {pageNumber} ]", Margin = new Thickness(0, 20, 0, 0),
            HorizontalAlignment = HorizontalAlignment.Right
        };
        Grid.SetRow(footer, 2);
        grid.Children.Add(footer);


        PrintHelper.AddFrameworkElementToPrint(grid);

    }
    catch
    {
    }
}

结果如下所示。可以看出，如果数据很大，则不会打印，因为不会自动添加下一页。我可以手动循环数据，并定义在一页上打印多少行，以及下一页打印多少行，但这不是我想要的，因为如果某些单元格数据很大，那么我的逻辑就不起作用。

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Answer 1

从该document派生。您可以在单独的页面上打印很长的DataGrid，但我们仍然需要在代码隐藏中手动分页您的数据。例如，如果我们想要以每页10个的速度削减数据源，我们需要像下面这样削减数据。

private PrintHelper _printHelper;

private async void Button_Click(object sender, RoutedEventArgs e)
{
    _printHelper = new PrintHelper(CustomPrintContainer);

    var pageNumber = 0;

    for (int i = 0; i < Items.Count; i = i + 10)
    {
        var grid = new Grid();
        grid.RowDefinitions.Add(new RowDefinition() { Height = GridLength.Auto });
        grid.RowDefinitions.Add(new RowDefinition() { Height = new GridLength(1, GridUnitType.Star) });
        grid.RowDefinitions.Add(new RowDefinition() { Height = GridLength.Auto });

        // Static header
        var header = new TextBlock { Text = "Custom Print", Margin = new Thickness(0, 0, 0, 20) };
        Grid.SetRow(header, 0);
        grid.Children.Add(header);

        // Main content with layout from data template
        var dataGrid = new DataGrid();
        dataGrid.AutoGenerateColumns = true;
        dataGrid.ItemsSource = Items.Skip(i).Take(10);
        Grid.SetRow(dataGrid, 1);
        grid.Children.Add(dataGrid);

        // Footer with page number
        pageNumber++;
        var footer = new TextBlock { Text = string.Format("page {0}", pageNumber), Margin = new Thickness(0, 20, 0, 0) };
        Grid.SetRow(footer, 2);
        grid.Children.Add(footer);

        _printHelper.AddFrameworkElementToPrint(grid);
    }

    _printHelper.OnPrintCanceled += _printHelper_OnPrintCanceled;
    _printHelper.OnPrintFailed += _printHelper_OnPrintFailed;
    _printHelper.OnPrintSucceeded += _printHelper_OnPrintSucceeded;

    var printHelperOptions = new PrintHelperOptions(false);
    printHelperOptions.Orientation = Windows.Graphics.Printing.PrintOrientation.Default;
    printHelperOptions.AddDisplayOption(StandardPrintTaskOptions.Orientation);
    await _printHelper.ShowPrintUIAsync("print sample", printHelperOptions);
}