File Support in WPF Syntax Editor

7 May 20215 minutes to read

Essential Edit WPF facilitates users to create, open, modify and save text files and programming language files. EditControl provides built-in support for a variety of text based file formats such as txt, cs, VB, SQL, XAML, and XML. It also enables to specify custom file types in the custom language configurations.

Opening a file

Opening a file in the EditControl can be done in the following three ways:

Using file path

The DocumentSource property of EditControl is used to specify the file to be opened with EditControl. The following code can be used to set the DocumentSource property.

<sfedit:EditControl x:Name="editControl" DocumentSource="C:\Content.txt" ShowLineNumber="False" EnableOutlining="False"/>
editControl.DocumentSource = @"C:\Content.txt";

The following image displays the contents from file set as DocumentSource window.

Open a file in syntax editor using file path

Opening through file dialog

Files can also be opened using the LoadFile method. LoadFile method displays a FileOpenDialog to enable you to choose the file that needs to be opened in the EditControl.


The following image displays the file open dialog.

Open a file in syntax editor using open file dialog

Dropping a file

The EditControl allows users to drop a file over it, by setting the AllowDrop property to true. Users can drop any type of file supported in the EditControl. The editor will automatically switch its DocumentLanguage based on dropped file’s extension. When dropping, if any documents is already in open, it will be closed, and the DocumentClosing event will occur. Here, you can control the desired action before closing.

this.editControl.AllowDrop = true;
Me.editControl.AllowDrop = True

Saving the text in a file

SaveFile method in the EditControl class is used to save the text in EditControl to a file. EditControl does support saving all the built-in languages, file types and custom language file type respectively.

Enable save file, by using the following code.


The following image displays the save file dialog.

Saving changes in a file using save file dialog

DocumentClosing event

By default, the existing file will not be saved when loading or dropping a new file. You can control this behavior using the DocumentClosing event, which occurs when closing a file. You can use the HasUnsavedChanges property to identify whether the existing file contains changes, based on which you can choose the action need to be performed.

DocumentClosingEventArgs Description
HasUnsavedChanges Represents a value that indicates whether the file contains unsaved changes.
Action Represents a value to specify the save actions.
SaveAction Description
Save Saves the changes before closing document.
Discard Ignores the changes and closes the document.
Cancel Cancels the current action that is being performed.
Prompt Opens a dialog for allowing users to choose one of the above actions.
public MainWindow()
            editControl.DocumentClosing += EditControl_DocumentClosing;

        private void EditControl_DocumentClosing(object sender, DocumentClosingEventArgs args)
               args.Action = SaveAction.Save;
editControl.DocumentClosing += AddressOf EditControl_DocumentClosing

        Private Sub EditControl_DocumentClosing(ByVal sender As Object, ByVal args As DocumentClosingEventArgs)
        If HasUnsavedChanges Then
        args.Action = SaveAction.Save
        End Ifargs.Action = SaveAction.Save
        End Sub