Question

我在启动打印过程时丢失了数据绑定，这可能吗？多数民众赞成在我的情况下我只能想到这一点，我在一个控件中有一个Table，使Table数据可绑定，全部在FlowDocument内。运行它时，数据绑定工作正常，表格会自行绘制一些数据，没有任何问题。

但是，打印时该控件的输出始终为空白。

我添加了一个ListView具有相同的绑定，在打印生成的数据时，它也显得丢失。

XAML：

<Window x:Class="GlassStore.InitBill"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:GlassStore.ViewModels"
        xmlns:flowdocs="clr-namespace:FlowDocuments;assembly=FlowDocument"
        Title="InitBill" Height="825" Width="1004">
<Window.DataContext>
    <local:InitBillViewModel/>
</Window.DataContext>
<Grid Background="White">
    <FlowDocumentReader HorizontalAlignment="Center"
                        HorizontalContentAlignment="Center">
        <FlowDocument ColumnWidth="999999"
                      IsColumnWidthFlexible="True"
                      TextAlignment="Center" 
                      Name="FD">
                <Paragraph>
                <ListView ItemsSource="{Binding GridTrans}">
                    <ListView.View>
                        <GridView>
                            <GridViewColumn Header="ffff"
                                 DisplayMemberBinding="{Binding CarModel}" />
                            <GridViewColumn Header="xxxx"
                                 DisplayMemberBinding="{Binding CarName}" />
                        </GridView>
                    </ListView.View>
                </ListView>
            </Paragraph>
            <Paragraph TextAlignment="Center">
                <TextBlock Text="{Binding test}" />
            </Paragraph>
            <flowdocs:ItemsContent ItemsSource="{Binding GridTrans}"
                                   Background="#FFF2C3C3"
                                   BorderThickness="2">
                <flowdocs:ItemsContent.ItemTemplate>
                    <DataTemplate>
                        <flowdocs:Fragment>
                            <Table>
                            <TableRowGroup flowdocs:Attached.IsItemsHost="True">
                                <TableRow Background="AliceBlue" >
                                    <TableCell Foreground="Red">
                                        <Paragraph>
                                            <flowdocs:BindableRun BoundText="{Binding CarName}" />
                                        </Paragraph>
                                    </TableCell>
                                    <TableCell Foreground="Green">
                                        <Paragraph>
                                            <flowdocs:BindableRun BoundText="{Binding CarModel}" />
                                        </Paragraph>
                                    </TableCell>
                                    <TableCell Foreground="Yellow">
                                        <Paragraph>
                                            <flowdocs:BindableRun BoundText="{Binding glassPrice}" />
                                        </Paragraph>
                                    </TableCell>
                                </TableRow>
                            </TableRowGroup>
                            </Table>
                        </flowdocs:Fragment>
                    </DataTemplate>
                </flowdocs:ItemsContent.ItemTemplate>
            </flowdocs:ItemsContent>
            <Table>
                <TableRowGroup>
                    <TableRow>
                        <TableCell>
                            <Paragraph>Row1 Cell1</Paragraph>
                        </TableCell>
                        <TableCell>
                            <Paragraph>Row2 Cell2</Paragraph>
                        </TableCell>
                    </TableRow>
                </TableRowGroup>
            </Table>  
        </FlowDocument>
    </FlowDocumentReader>
    <Button Command="{Binding print}"
            Content="إطـبع"
            Height="29" Margin="91,0,112,41"
            Name="button1"
            VerticalAlignment="Bottom" />
</Grid>
</Window>

现在我知道问题不在于自定义控件，因为我现在遇到与ListView相同的问题。

我已将源附加到Window版本here和打印版本here。

Answer 1

ViewModel会很好，尤其是print命令背后的方法。我的猜测是，将flowdocument放入特殊的打印上下文并丢失窗口的datacontext。

尝试删除

<Window.DataContext>
    <local:InitBillViewModel/>
</Window.DataContext>

并使用

<FlowDocumentReader HorizontalAlignment="Center" HorizontalContentAlignment="Center">
    <FlowDocumentReader.DataContext>
        <local:InitBillViewModel/>
    </FlowDocumentReader.DataContext>
...

代替。也许这有帮助吗？

编辑：当然，打印命令必须移动到另一个ViewModel才能继续工作。在Window.DataContext中，这个其他ViewModel将保留原来的那个。

Answer 2

这是我的解决方案：

在单独的XAML文件中定义文档：

Load the Flow Document from Resource Dictionary Xaml

然后打印：

    var prntDlg = new PrintDialog();
    var res = Application.LoadComponent(new Uri("/Resources/ReportDocument.xaml", UriKind.RelativeOrAbsolute)) as ResourceDictionary;
    var doc = res["ReportFlowDoc"] as FlowDocument;

    doc.DataContext = this.fdswReport.Document.DataContext; //your FlowDocumentScrollViewer
    doc.PageWidth = prntDlg.PrintableAreaWidth;
    doc.PageHeight = prntDlg.PrintableAreaHeight;
    doc.ColumnWidth = prntDlg.PrintableAreaWidth;
    doc.PagePadding = new Thickness(80);
    doc.IsOptimalParagraphEnabled = true;
    doc.IsHyphenationEnabled = true;

    if (prntDlg.ShowDialog() == true)
        prntDlg.PrintDocument(((IDocumentPaginatorSource)doc).DocumentPaginator, "Report");

打印数据绑定的FlowDocument时，数据绑定丢失

2 个答案: