我正在尝试使用 MVVM 架构打印我的窗口(打印预览)。到目前为止，我能够将窗口的控件打印到打印中。但它没有显示数据绑定(bind)。
这是我的 PrintPreview.xaml 代码
<ScrollViewer VerticalScrollBarVisibility="Auto">
<!--Main Grid-->
<Grid x:Name="MainGrid">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="2.5*"/>
<ColumnDefinition Width="3*"/>
<ColumnDefinition Width="2.5*"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height ="1.5*"/>
<RowDefinition Height ="1.7*"/>
<RowDefinition Height ="5*" MinHeight="200"/>
<RowDefinition Height ="7*" MinHeight="200"/>
<RowDefinition Height ="6*" MinHeight="100"/>
<RowDefinition Height ="2*"/>
</Grid.RowDefinitions>
<Grid Grid.RowSpan="2" Grid.ColumnSpan="3" Background="#9dc6a7"/>
<!--Patient Id block-->
<StackPanel Grid.ColumnSpan="2" Style="{StaticResource StackpanelStyle}">
<Label FontSize="16" FontWeight="Bold" Foreground="White">
Patient ID :
</Label>
<Label FontSize="16" Foreground="White" Margin="5,0,0,0" Content="{Binding Path=PatientID}"/>
</StackPanel>
<!--Date block-->
<StackPanel Grid.ColumnSpan="3" Style="{StaticResource StackpanelStyle}" HorizontalAlignment="Right">
<Label FontSize="16" FontWeight="Bold" Foreground="White">
Date :
</Label>
<Label Name="date_time" FontSize="16" Foreground="White" Margin="5,0" Content="{Binding Path=CurrentDate}"/>
</StackPanel>
<!--Title block-->
<TextBlock Grid.Row="1" Grid.ColumnSpan="3" HorizontalAlignment="Center" VerticalAlignment="Center" FontSize="20" FontWeight="Bold" TextDecorations="Underline" Foreground="White">
Patient Registration Information
</TextBlock>
<!--Sub grid 1-->
<Grid Grid.Row="2" Grid.ColumnSpan="3" HorizontalAlignment="Center" VerticalAlignment="Stretch" Margin="25,10,25,10">
<!--User's image View and name-->
<StackPanel HorizontalAlignment="Center" VerticalAlignment="Center" Orientation="Vertical">
<Ellipse Width="150" Height="150">
<Ellipse.Fill>
<ImageBrush x:Name="ImageViewer2" ImageSource="{Binding Path=PatientImageSource}"/>
</Ellipse.Fill>
</Ellipse>
<StackPanel HorizontalAlignment="Left" Orientation="Horizontal" Margin="0,10">
<Label Style="{StaticResource LabelStyles}" Margin="0">Patient Name :</Label>
<TextBlock x:Name="ViewName" Style="{StaticResource TextBlockStyle}" Text="{Binding Path = PatientName}"/>
</StackPanel>
</StackPanel>
</Grid>
<!--Sub grid 2-->
<GroupBox Grid.Row="3" Grid.ColumnSpan="3" HorizontalAlignment="Stretch" VerticalAlignment="Center" Margin="25,-35,25,0">
<GroupBox.Header>
<TextBlock Style="{StaticResource TextBlockStyleControl}">Patient Personal Information</TextBlock>
</GroupBox.Header>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="500*"/>
<ColumnDefinition Width="500*"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="5*"/>
<RowDefinition Height="3*" MaxHeight="80"/>
</Grid.RowDefinitions>
<StackPanel Grid.Row="0" Grid.Column="0" Orientation="Vertical" Margin="10,5">
<Label Style="{StaticResource PreviewLabelStyles}" >Address :</Label>
<TextBlock x:Name="ViewANum" Style="{StaticResource TextBlockStyle}" Text="{Binding Path = PatientAddress.Number}"/>
<TextBlock x:Name="ViewAStrt" Style="{StaticResource TextBlockStyle}" Text="{Binding Path = PatientAddress.Street}"/>
<TextBlock x:Name="ViewACity" Style="{StaticResource TextBlockStyle}" Text="{Binding Path = PatientAddress.City}"/>
</StackPanel>
<StackPanel Grid.Row="0" Grid.Column="1" Orientation="Vertical" Margin="50,5,10,10">
<Label Style="{StaticResource PreviewLabelStyles}">Gender :</Label>
<TextBlock x:Name="ViewGender" Style="{StaticResource TextBlockStyle}" Text="{Binding Path = PatientGender}"/>
</StackPanel>
<StackPanel Grid.Row="1" Grid.Column="0" Orientation="Vertical" Margin="10,5">
<Label Style="{StaticResource PreviewLabelStyles}">Date of Birth :</Label>
<TextBlock x:Name="ViewDob" Style="{StaticResource TextBlockStyle}" Text="{Binding Path = PatientDateOfBirth}"/>
</StackPanel>
<StackPanel Grid.Row="1" Grid.Column="1" Orientation="Vertical" Margin="50,5,10,5">
<Label Style="{StaticResource PreviewLabelStyles}">Age :</Label>
<TextBlock x:Name="ViewAge" Style="{StaticResource TextBlockStyle}" Text="{Binding Path = PatientAge}"/>
</StackPanel>
</Grid>
</GroupBox>
<!--Sub grid 3-->
<GroupBox Grid.Row="4" Grid.ColumnSpan="3" HorizontalAlignment="Stretch" VerticalAlignment="Center" Margin="25,-25,25,0">
<GroupBox.Header>
<TextBlock Style="{StaticResource TextBlockStyleControl}">Patient Medical Information</TextBlock>
</GroupBox.Header>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="500*"/>
<ColumnDefinition Width="500*"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="3*"/>
<RowDefinition Height="3*" />
</Grid.RowDefinitions>
<StackPanel Grid.Row="0" Grid.Column="0" Orientation="Vertical" Margin="10,5">
<Label Style="{StaticResource PreviewLabelStyles}">Department :</Label>
<TextBlock x:Name="ViewDepartment" Style="{StaticResource TextBlockStyle}" Text="{Binding Path=PatientDepartment}"/>
</StackPanel>
<StackPanel Grid.Row="0" Grid.Column="1" Orientation="Vertical" Margin="50,5,10,0">
<Label Style="{StaticResource PreviewLabelStyles}">Ward :</Label>
<TextBlock x:Name="ViewWard" Style="{StaticResource TextBlockStyle}" Text="{Binding Path=PatientWard}"/>
</StackPanel>
<StackPanel Grid.Row="1" Grid.Column="0" Orientation="Vertical" Margin="10,5,10,10">
<Label Style="{StaticResource PreviewLabelStyles}">Doctor in Charge :</Label>
<TextBlock x:Name="ViewDoc" Style="{StaticResource TextBlockStyle}" Text="{Binding Path=PatientDotorcInCharge}"/>
</StackPanel>
</Grid>
</GroupBox>
<Button Grid.Row="5" Grid.Column="2" Style="{StaticResource ButtonStyle}" HorizontalAlignment="Right" VerticalAlignment="Top" Margin="20,7,26,0" Content="Print Content" Command="{Binding Path=PrintCommand}"/>
</Grid>
</ScrollViewer>
这是我的 PrintPreview ViewModel 代码，
class PrintPreviewViewModel
{
#region Data Members
private IWindowService m_windowService;
#endregion
#region Constructors
public PrintPreviewViewModel(PatientRecordDetailsModel patient)
{
string id = patient.PatientId;
PatientID = id.PadRight(6).Substring(0, 6);
PatientName = patient.PatientName;
PatientAddress = patient.PatientAddress;
PatientGender = patient.PatientGender;
PatientDateOfBirth = patient.PatientDateOfBirth.ToShortDateString();
PatientAge = patient.PatientAge;
PatientImageSource = patient.PatientImageSource;
PatientDepartment = patient.PatientDepartment;
PatientWard = patient.PatientWard;
PatientDotorcInCharge = patient.PatientDoctorInCharge;
m_windowService = new WindowService();
}
#endregion
#region Properties
public string PatientID { get; set; }
public string PatientName { get; set; }
public PatientAddress PatientAddress { get; set; }
public string PatientGender { get; set; }
public string PatientDateOfBirth { get; set; }
public int PatientAge { get; set; }
public ImageSource PatientImageSource { get; set; }
public string PatientDepartment { get; set; }
public string PatientWard { get; set; }
public string PatientDotorcInCharge { get; set; }
#endregion
#region <PrintPreview> Members
public string CurrentDate => m_windowService.GetCurrentDate();
#endregion
#region Properties : Commands
public ICommand PrintCommand
{
get => new PatientRecordDetailsCommands(param => OnPrintCommandExecute(), param => OnPrintCommandCanExecute());
}
#endregion
#region Handlers : Commands
private void OnPrintCommandExecute()
{
m_windowService.PrintWindow();
}
private bool OnPrintCommandCanExecute()
{
return true;
}
#endregion
}
}
如您所见，我正在通过服务类从另一个窗口打开 printPreview 窗口。患者对象正在通过它发送。打印按钮命令的实现也在同一个服务类中定义。我使用这种方法来减少 MVVM 违规。
这是我的服务类
class WindowService : IWindowService
{
public void CreateWindow(PatientRecordDetailsModel patient)
{
PrintPreview printPreview = new PrintPreview();
printPreview.DataContext = new PrintPreviewViewModel(patient);
printPreview.Show();
}
public string GetCurrentDate()
{
DateTime dateTime = DateTime.Now;
string date = dateTime.ToString("d");
string time = dateTime.ToString("T");
string Date_Time = date + " " + time;
return Date_Time;
}
public void PrintWindow()
{
PrintPreview printPreview = new PrintPreview();
PrintDialog printDlg = new PrintDialog();
PrintQueue ReceiptPrinter = new LocalPrintServer().GetPrintQueue("Microsoft Print To PDF");
PrintCapabilities PC = ReceiptPrinter.GetPrintCapabilities();
printDlg.PrintQueue = ReceiptPrinter;
printPreview.Measure(new Size(Double.PositiveInfinity, Double.PositiveInfinity));
Size PreGridSize = printPreview.DesiredSize;
double Scale = Math.Min(PC.PageImageableArea.ExtentWidth / PreGridSize.Width, PC.PageImageableArea.ExtentHeight / PreGridSize.Height);
printPreview.LayoutTransform = new System.Windows.Media.ScaleTransform(Scale, Scale);
Size PaperSize = new Size(PC.PageImageableArea.ExtentWidth, Math.Min(PC.PageImageableArea.ExtentHeight, PreGridSize.Height));
printPreview.Measure(PaperSize);
Point ptGrid = new Point(PC.PageImageableArea.OriginWidth, PC.PageImageableArea.OriginHeight);
printPreview.Arrange(new Rect(ptGrid, PaperSize));
Application.Current.Dispatcher.BeginInvoke(
new Action(delegate () { printDlg.PrintVisual(printPreview.MainGrid, "PrintPreview"); }),
DispatcherPriority.Send);
}
}
我尝试将患者对象分配给 PrintWindow() 内的数据上下文，但它返回一个空对象。
This is the original printPreview Window
This is how the print looks like
所以我想应该有一个正确的方法来做到这一点。
最佳答案
您的问题是您没有在 PrintWindow 函数中分配 DataContext 。
让我们来看看
public void PrintWindow()
{
在这里我们创建一个新的打印预览
PrintPreview printPreview = new PrintPreview();
PrintDialog printDlg = new PrintDialog();
PrintQueue ReceiptPrinter = new LocalPrintServer().GetPrintQueue("Microsoft Print To PDF");
PrintCapabilities PC = ReceiptPrinter.GetPrintCapabilities();
printDlg.PrintQueue = ReceiptPrinter;
printPreview.Measure(new Size(Double.PositiveInfinity, Double.PositiveInfinity));
Size PreGridSize = printPreview.DesiredSize;
double Scale = Math.Min(PC.PageImageableArea.ExtentWidth / PreGridSize.Width, PC.PageImageableArea.ExtentHeight / PreGridSize.Height);
printPreview.LayoutTransform = new System.Windows.Media.ScaleTransform(Scale, Scale);
Size PaperSize = new Size(PC.PageImageableArea.ExtentWidth, Math.Min(PC.PageImageableArea.ExtentHeight, PreGridSize.Height));
printPreview.Measure(PaperSize);
Point ptGrid = new Point(PC.PageImageableArea.OriginWidth, PC.PageImageableArea.OriginHeight);
printPreview.Arrange(new Rect(ptGrid, PaperSize));
Application.Current.Dispatcher.BeginInvoke(
new Action(delegate () { printDlg.PrintVisual(printPreview.MainGrid, "PrintPreview"); }),
DispatcherPriority.Send);
}
如您所见，您没有将数据上下文分配给它。实际上，您在其中分配数据上下文的 createiwndow 函数根本不会被调用。
您可以在这里看到打印命令调用 PrintWindow 函数而不是 createwindow。
#region Properties : Commands
public ICommand PrintCommand
{
get => new PatientRecordDetailsCommands(param => OnPrintCommandExecute(), param => OnPrintCommandCanExecute());
}
#endregion
#region Handlers : Commands
private void OnPrintCommandExecute()
{
m_windowService.PrintWindow();
}
private bool OnPrintCommandCanExecute()
{
return true;
}
#endregion
关于c# - 我的打印 PDF 不显示原始窗口的绑定(bind)数据 - C# MVVM，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/61223410/