Print WPF Visuals with MVVM pattern - mvvm

Question

My ViewModel has a PrintCommand executing a Method called PrintCalendar(). But the Calendar aka datagrid is in the View, so how do I get my datagrid into the ViewModel?
Getting my hands dirty and do all that stuff in code-behind? oh no...
PrintDialog printDlg = new PrintDialog();
printDlg.PrintVisual(datagrid, "Grid Printing.");

Answer 1

You could try this. I have set up a simple demo window with a datagrid, a buttom and a ViewModel. The ViewModel contains the PrintCommand (a RelayCommand from the MVVM Light Toolkit) which accepts a Visual (the datagrid) as the command parameter. There is no code in the code behind all the work is done via binding.
The Xaml:
<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:vm="clr-namespace:WpfTestApplication.ViewModel"
x:Class="WpfTestApplication.MainWindow"
x:Name="Window"
Title="MainWindow"
Width="640" Height="480">
<Window.Resources>
<ResourceDictionary>
<vm:WindowViewModel x:Key="WindowViewModel"/>
</ResourceDictionary>
</Window.Resources>
<Grid x:Name="LayoutRoot" DataContext="{DynamicResource WindowViewModel}">
<DockPanel>
<Button Content="Print" Width="70" DockPanel.Dock="Bottom" HorizontalAlignment="Right"
Command="{Binding PrintCommand, Mode=OneWay}" CommandParameter="{Binding ElementName=dataGrid, Mode=OneWay}" />
<DataGrid x:Name="dataGrid" DataContext="{DynamicResource SampleDataSource}" ItemsSource="{Binding Collection}"/>
</DockPanel>
</Grid>
</Window>
and the ViewModel:
using System.Windows.Controls;
using System.Windows.Media;
using GalaSoft.MvvmLight.Command;
namespace WpfTestApplication.ViewModel
{
public class WindowViewModel
{
/// <summary>
/// Command executed to print an visual component. The component is passed in as a parameter.
/// </summary>
public RelayCommand<Visual> PrintCommand
{
get
{
return new RelayCommand<Visual>( v =>
{
PrintDialog printDlg = new PrintDialog();
printDlg.PrintVisual( v, "Grid Printing." );
} );
}
}
}
}

Answer 2

I guess we need the following to be able to show the print dialog box as well:
public RelayCommand<Visual> PrintCommand
{
get
{
return new RelayCommand<Visual>( v =>
{
PrintDialog printDlg = new PrintDialog();
if (Convert.ToBoolean(myPrintDialog.ShowDialog()))
{
printDlg.PrintVisual( v, "Grid Printing." );
}
});
}
}