Loading a text file in a WPF FlowDocumentReader

In this article, I demonstrate how to load a text file in a FlowDocumentReader available in WPF using C#.

The attached project is a WPF application written in C# and XAML. It uses OpenFileDialog to browse text files and once text file is selected, it is loaded in a FlowDocumentReader that allows you to view, paging, and find options.

First, let's create a UI with a TextBox, a Button, and a FlowDocumentViewer control.

The UI looks like Figure 1.

 

Figure 1

 

The XAML code for the UI looks like this.

 

<Window x:Class="LoadTextFileInFlowDocumentViewerSample.Window1"         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"         Title="Window1" Height="290" Width="600">     <Canvas>         <TextBox Height="32" HorizontalAlignment="Left" Margin="6,10,0,0" Name="FileNameTextBox"                  VerticalAlignment="Top" Width="393" />         <Button Content="Browse" Height="32" HorizontalAlignment="Left" Margin="405,10,0,0"                 Name="button1" VerticalAlignment="Top" Width="88" Click="button1_Click" />                   <FlowDocumentReader Name="FlowDocReader" Background="LightBlue"                                 Canvas.Top="50" Canvas.Left="5" Width="560"                                 Height="210">         </FlowDocumentReader>     </Canvas> </Window>

On Button control, we will browse a text file and set TextBox.Text property to the selected file. As you can see from code below, we create a Paragraph and add the selected text file using Paragraph.Inlines.Add method. After that, we create a FlowDocument by passing this Paragraph and in the end; we set FlowDocumentReader.Document property to the FlowDocument.

 

Code sample in C#:

 

private void button1_Click(object sender, RoutedEventArgs e) {     // Create OpenFileDialog     Microsoft.Win32.OpenFileDialog dlg = new Microsoft.Win32.OpenFileDialog();                  // Set filter for file extension and default file extension     dlg.DefaultExt = ".txt";     dlg.Filter = "Text documents (.txt)|*.txt";       // Display OpenFileDialog by calling ShowDialog method     Nullable<bool> result = dlg.ShowDialog();       // Get the selected file name and display in a TextBox     if (result == true)     {         // Open document         string filename = dlg.FileName;         FileNameTextBox.Text = filename;           Paragraph paragraph = new Paragraph();         paragraph.Inlines.Add(System.IO.File.ReadAllText(filename));         FlowDocument document = new FlowDocument(paragraph);         FlowDocReader.Document = document;     } }

 

Code sample in VB.NET:

 

Private Sub button1_Click(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs)         'Create OpenFileDialog         Dim dlg As Microsoft.Win32.OpenFileDialog = New Microsoft.Win32.OpenFileDialog()           ' Set filter for file extension and default file extension         dlg.DefaultExt = ".txt"         dlg.Filter = "Text documents (.txt)|*.txt"           ' Display OpenFileDialog by calling ShowDialog method         If (dlg.ShowDialog() = True) Then               '; Open document             Dim filename As String = dlg.FileName             FileNameTextBox.Text = filename               Dim paragraph As Paragraph = New Paragraph()             paragraph.Inlines.Add(System.IO.File.ReadAllText(filename))             Dim document As FlowDocument = New FlowDocument(paragraph)             FlowDocReader.Document = document         End If       End Sub

 

Now if you run the application and browse a text file, the output looks like Figure 2.

 

Figure 2