C# WPF PrintDialog 打印（2）

前面https://www.cnblogs.com/yinyu5/p/18633910使用PrintVisual方法只打印了可见部分的元素，所以这里改为使用PrintDocument方法来进行打印。

需要引用System.Printing.dll

界面代码：

 1 <Window x:Class="WpfApp123.MainWindow"
 2         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
 3         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
 4         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
 5         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
 6         xmlns:local="clr-namespace:WpfApp123"
 7         mc:Ignorable="d"
 8         Title="MainWindow" Height="600" Width="800">
 9     <Grid>
10         <Grid.RowDefinitions>
11             <RowDefinition></RowDefinition>
12             <RowDefinition></RowDefinition>
13             <RowDefinition Height="auto"></RowDefinition>
14         </Grid.RowDefinitions>
15         <Canvas x:Name="print_Canvas">
16             <Ellipse Margin="10" Height="100" Width="300">
17                 <Ellipse.Fill>
18                     <LinearGradientBrush>
19                         <GradientStop Color="Purple" Offset="0"></GradientStop>
20                         <GradientStop Color="DarkBlue" Offset="1"></GradientStop>
21                     </LinearGradientBrush>
22                 </Ellipse.Fill>
23             </Ellipse>
24             <Rectangle Height="80" Width="200" Margin="400 30 0 0">
25                 <Rectangle.Fill>
26                     <LinearGradientBrush>
27                         <GradientStop Color="Red" Offset="0"></GradientStop>
28                         <GradientStop Color="Green" Offset="0.5"></GradientStop>
29                         <GradientStop Color="DarkBlue" Offset="1"></GradientStop>
30                     </LinearGradientBrush>
31                 </Rectangle.Fill>
32             </Rectangle>
33             <TextBlock Canvas.Left="200" Canvas.Top="150" FontSize="50">
34                 ABCDEFG
35             </TextBlock>
36         </Canvas>
37         <Grid Grid.Row="1">
38             <DataGrid Name="print_dg">
39             </DataGrid>
40         </Grid>
41         <Grid Grid.Row="2" Margin="10">
42             <StackPanel Orientation="Horizontal" HorizontalAlignment="Center">
43                 <Button Height="40" Width="200" FontSize="20" Margin="3" Click="Button_Click">打印Canvas</Button>
44                 <Button Height="40" Width="200" FontSize="20" Margin="3" Click="Button1_Click">打印DataGrid</Button>
45             </StackPanel>
46         </Grid>
47     </Grid>
48 </Window>

使用PrintDocument方法的后台代码：

private void PrintDocument_Method()
        {
            PrintDialog printDialog = new PrintDialog();
            printDialog.PrintQueue = LocalPrintServer.GetDefaultPrintQueue();
            printDialog.PageRangeSelection = PageRangeSelection.AllPages;
            if (printDialog.ShowDialog() == true)
            {
                FixedDocument fixedDoc = new FixedDocument();
                Size pageSize = new Size(printDialog.PrintableAreaWidth, printDialog.PrintableAreaHeight);
                PageContent pageContent = new PageContent();
                FixedPage fixedPage = new FixedPage();
                fixedPage.Width = pageSize.Width;
                fixedPage.Height = pageSize.Height;

                Canvas canvas = new Canvas();
                canvas.Height = print_Canvas.Height;
                canvas.Width = print_Canvas.Width;
                //复制Canvas里面的元素
                foreach (UIElement element in print_Canvas.Children)
                {
                    UIElement clonedElement = CloneElement(element);
                    canvas.Children.Add(clonedElement);
                }
                fixedPage.Children.Add(canvas);
                ((IAddChild)pageContent).AddChild(fixedPage);
                fixedDoc.Pages.Add(pageContent);
                printDialog.PrintDocument(fixedDoc.DocumentPaginator, "打印 Canvas");
            }
        }

        private UIElement CloneElement(UIElement element)
        {
            // 使用 XAML 序列化反序列化来实现 UIElement 的深度复制
            string xamlString = System.Windows.Markup.XamlWriter.Save(element);
            return (UIElement)System.Windows.Markup.XamlReader.Parse(xamlString);
        }

可以看到被遮挡的元素也能打印出来：

那么DataGrid中遮挡的数据该如何打印呢？特别是数据行数较多，可能需要多页打印时。

还是使用PrintDocument，这里做一个简单的分页处理。