---
title: Load Files into RichTextBox Control
ms.date: "03/30/2017"
dev_langs:
  - "csharp"
  - "vb"
  - "cpp"
helpviewer_keywords:
  - "text boxes [Windows Forms], displaying files"
  - "examples [Windows Forms], text boxes"
  - ".rtf files [Windows Forms], opening in RichTextBox control"
  - "RTF files [Windows Forms], opening in RichTextBox control"
  - "text files [Windows Forms], displaying in RichTextBox control"
  - ".rtf files [Windows Forms], displaying in RichTextBox control"
  - "RichTextBox control [Windows Forms], opening files"
  - "RTF files [Windows Forms], displaying in RichTextBox control"
ms.assetid: c03451be-f285-4428-a71a-c41e002cc919
---
# How to: Load Files into the Windows Forms RichTextBox Control

The Windows Forms <xref:System.Windows.Forms.RichTextBox> control can display a plain-text, Unicode plain-text, or Rich-Text-Format (RTF) file. To do so, call the <xref:System.Windows.Forms.RichTextBox.LoadFile%2A> method. You can also use the <xref:System.Windows.Forms.RichTextBox.LoadFile%2A> method to load data from a stream. For more information, see <xref:System.Windows.Forms.RichTextBox.LoadFile%28System.IO.Stream%2CSystem.Windows.Forms.RichTextBoxStreamType%29>.

### To load a file into the RichTextBox control

1. Determine the path of the file to be opened using the <xref:System.Windows.Forms.OpenFileDialog> component. For an overview, see [OpenFileDialog Component Overview](openfiledialog-component-overview-windows-forms.md).

2. Call the <xref:System.Windows.Forms.RichTextBox.LoadFile%2A> method of the <xref:System.Windows.Forms.RichTextBox> control, specifying the file to load and optionally a file type. In the example below, the file to load is taken from the <xref:System.Windows.Forms.OpenFileDialog> component's <xref:System.Windows.Forms.FileDialog.FileName%2A> property. If you call the method with a file name as its only argument, the file type will be assumed to be RTF. To specify another file type, call the method with a value of the <xref:System.Windows.Forms.RichTextBoxStreamType> enumeration as its second argument.

    In the example below, the <xref:System.Windows.Forms.OpenFileDialog> component is shown when a button is clicked. The file selected is then opened and displayed in the <xref:System.Windows.Forms.RichTextBox> control. This example assumes a form has a button,`btnOpenFile`.

    ```vb
    Private Sub btnOpenFile_Click(ByVal sender As System.Object, _
       ByVal e As System.EventArgs) Handles btnOpenFile.Click
         If OpenFileDialog1.ShowDialog() = DialogResult.OK Then
           RichTextBox1.LoadFile(OpenFileDialog1.FileName, _
              RichTextBoxStreamType.RichText)
          End If
    End Sub
    ```

    ```csharp
    private void btnOpenFile_Click(object sender, System.EventArgs e)
    {
       if(openFileDialog1.ShowDialog() == DialogResult.OK)
       {
         richTextBox1.LoadFile(openFileDialog1.FileName, RichTextBoxStreamType.RichText);
       }
    }
    ```

    ```cpp
    private:
       void btnOpenFile_Click(System::Object ^  sender,
          System::EventArgs ^  e)
       {
          if(openFileDialog1->ShowDialog() == DialogResult::OK)
          {
             richTextBox1->LoadFile(openFileDialog1->FileName,
                RichTextBoxStreamType::RichText);
          }
       }
    ```

    (Visual C#, Visual C++) Place the following code in the form's constructor to register the event handler.

    ```csharp
    this.btnOpenFile.Click += new System.EventHandler(this. btnOpenFile_Click);
    ```

    ```cpp
    this->btnOpenFile->Click += gcnew
       System::EventHandler(this, &Form1::btnOpenFile_Click);
    ```

    > [!IMPORTANT]
    > To run this process, your assembly may require a privilege level granted by the <xref:System.Security.Permissions.FileIOPermission?displayProperty=nameWithType> class. If you are running in a partial-trust context, the process might throw an exception because of insufficient privileges. For more information, see [Code Access Security Basics](https://docs.microsoft.com/dotnet/framework/misc/code-access-security-basics).

## See also

- <xref:System.Windows.Forms.RichTextBox.LoadFile%2A?displayProperty=nameWithType>
- <xref:System.Windows.Forms.RichTextBox>
- [RichTextBox Control](richtextbox-control-windows-forms.md)
- [Controls to Use on Windows Forms](controls-to-use-on-windows-forms.md)