使用 windows-community-toolkit 的 Print Helper 扩展分页

Question

我正在使用windows-community-toolkit 的PrintHelper 扩展名并打印一些数据。问题是当数据很大时它与页面重叠，我找不到动态添加新页面并将数据转移到下一页的方法。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。我可以这样做是手动循环数据并准确定义要在一页上打印多少行以及在下一页上打印多少行，但这不是我想要的，因为如果某些单元格数据很大，那么我的逻辑将不起作用。

Answer 1

派生自此document。您可以在单独的页面上打印长 DataGrid，但我们仍然需要在代码隐藏中手动分页您的数据。例如，如果我们要对每页十个的数据源进行切割，我们需要像下面这样切割数据。

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);
}