RichTextBox.LoadFile Method

Reference

Definition

Namespace:: System.Windows.Forms

Assembly:: System.Windows.Forms.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Loads the contents of a file into the RichTextBox control.

Overloads

LoadFile(String)	Loads a rich text format (RTF) or standard ASCII text file into the RichTextBox control.
LoadFile(Stream, RichTextBoxStreamType)	Loads the contents of an existing data stream into the RichTextBox control.
LoadFile(String, RichTextBoxStreamType)	Loads a specific type of file into the RichTextBox control.

LoadFile(String)

Loads a rich text format (RTF) or standard ASCII text file into the RichTextBox control.

public:
 void LoadFile(System::String ^ path);

public void LoadFile (string path);

member this.LoadFile : string -> unit

Public Sub LoadFile (path As String)

Parameters

path: String

The name and location of the file to load into the control.

Exceptions

IOException

An error occurred while loading the file into the control.

ArgumentException

The file being loaded is not an RTF document.

Examples

The following code example opens an RTF file into the RichTextBox control. The example uses the OpenFileDialog class to display a dialog to request the file from the user. The code then loads that file assuming that it is an RTF document file. If the file is not, the example code will throw an exception. This example requires that the code is placed in a Form class that has a RichTextBox control named richTextBox1.

public:
   void LoadMyFile()
   {
      // Create an OpenFileDialog to request a file to open.
      OpenFileDialog^ openFile1 = gcnew OpenFileDialog;
      
      // Initialize the OpenFileDialog to look for RTF files.
      openFile1->DefaultExt = "*.rtf";
      openFile1->Filter = "RTF Files|*.rtf";
      
      // Determine whether the user selected a file from the OpenFileDialog.
      if ( openFile1->ShowDialog() == System::Windows::Forms::DialogResult::OK &&
         openFile1->FileName->Length > 0 )
      {
         // Load the contents of the file into the RichTextBox.
         richTextBox1->LoadFile( openFile1->FileName );
      }
   }

public void LoadMyFile()
{
   // Create an OpenFileDialog to request a file to open.
   OpenFileDialog openFile1 = new OpenFileDialog();

   // Initialize the OpenFileDialog to look for RTF files.
   openFile1.DefaultExt = "*.rtf";
   openFile1.Filter = "RTF Files|*.rtf";

   // Determine whether the user selected a file from the OpenFileDialog.
   if(openFile1.ShowDialog() == System.Windows.Forms.DialogResult.OK &&
      openFile1.FileName.Length > 0) 
   {
      // Load the contents of the file into the RichTextBox.
      richTextBox1.LoadFile(openFile1.FileName);
   }
}

Public Sub LoadMyFile()
    ' Create an OpenFileDialog to request a file to open.
    Dim openFile1 As New OpenFileDialog()
    
    ' Initialize the OpenFileDialog to look for RTF files.
    openFile1.DefaultExt = "*.rtf"
    openFile1.Filter = "RTF Files|*.rtf"
    
    ' Determine whether the user selected a file from the OpenFileDialog.
    If (openFile1.ShowDialog() = System.Windows.Forms.DialogResult.OK) _
        And (openFile1.FileName.Length > 0) Then
        
        ' Load the contents of the file into the RichTextBox.
        richTextBox1.LoadFile(openFile1.FileName)
    End If
End Sub

Remarks

When loading a file with the LoadFile method, the contents of the file being loaded replace the entire contents of the RichTextBox control. This will cause the values of the Text and Rtf properties to change. You can use this method to load a previously created text or RTF document into the control for manipulation. If you want to save the file, you can use the SaveFile method.

Note

With this version of the LoadFile method, if the file being loaded is not an RTF document, an exception will occur. To load a different type of file such as an ASCII text file, use the other versions of this method that accept a value from the RichTextBoxStreamType enumeration as a parameter.

Note

The LoadFile method will not open a file until a handle is created for the RichTextBox. Ensure that the control's handle is created before calling the LoadFile method.

Applies to

LoadFile(Stream, RichTextBoxStreamType)

Loads the contents of an existing data stream into the RichTextBox control.

public:
 void LoadFile(System::IO::Stream ^ data, System::Windows::Forms::RichTextBoxStreamType fileType);

public void LoadFile (System.IO.Stream data, System.Windows.Forms.RichTextBoxStreamType fileType);

member this.LoadFile : System.IO.Stream * System.Windows.Forms.RichTextBoxStreamType -> unit

Public Sub LoadFile (data As Stream, fileType As RichTextBoxStreamType)

Parameters

data: Stream

A stream of data to load into the RichTextBox control.

fileType: RichTextBoxStreamType

One of the RichTextBoxStreamType values.

Exceptions

IOException

An error occurred while loading the file into the control.

ArgumentNullException

.NET 5 and later: The data argument is null.

ArgumentException

The file being loaded is not an RTF document.

Examples

The following code example demonstrates using the SaveFile and LoadFile methods with streams. It also demonstrates using the FileDialog.FileName, FileDialog.DefaultExt, SaveFileDialog.CreatePrompt, and SaveFileDialog.OverwritePrompt members.

This is a complete example that's ready to run when you copy it to your project.

using namespace System;
using namespace System::Drawing;
using namespace System::IO;
using namespace System::Windows::Forms;

public ref class Form1: public Form
{
public private:
   RichTextBox^ RichTextBox1;
   Button^ Button1;
   RichTextBox^ RichTextBox2;
   Button^ Button2;
   SaveFileDialog^ SaveFileDialog1;

public:
   Form1()
      : Form()
   {
      userInput = gcnew MemoryStream;
      this->RichTextBox1 = gcnew RichTextBox;
      this->Button1 = gcnew Button;
      this->RichTextBox2 = gcnew RichTextBox;
      this->Button2 = gcnew Button;
      this->SaveFileDialog1 = gcnew SaveFileDialog;
      this->SuspendLayout();
      this->RichTextBox1->Location = Point( 24, 64 );
      this->RichTextBox1->Name = "RichTextBox1";
      this->RichTextBox1->TabIndex = 0;
      this->RichTextBox1->Text = "Type something here.";
      this->Button1->Location = Point( 96, 16 );
      this->Button1->Name = "Button1";
      this->Button1->Size = Size( 96, 24 );
      this->Button1->TabIndex = 1;
      this->Button1->Text = "Save To Stream";
      this->Button1->Click += 
          gcnew EventHandler( this, &Form1::Button1_Click );
      this->RichTextBox2->Location = Point( 152, 64 );
      this->RichTextBox2->Name = "RichTextBox2";
      this->RichTextBox2->TabIndex = 3;
      this->RichTextBox2->Text = "It will be added to the stream "
      "and appear here.";
      this->Button2->Location = Point( 104, 200 );
      this->Button2->Name = "Button2";
      this->Button2->Size = Size( 88, 32 );
      this->Button2->TabIndex = 4;
      this->Button2->Text = "Save Stream To File";
      this->Button2->Click += 
          gcnew EventHandler( this, &Form1::Button2_Click );
      this->ClientSize = Size( 292, 266 );
      this->Controls->Add( this->Button2 );
      this->Controls->Add( this->RichTextBox2 );
      this->Controls->Add( this->Button1 );
      this->Controls->Add( this->RichTextBox1 );
      this->Name = "Form1";
      this->Text = "Form1";
      this->ResumeLayout( false );
   }

   // Declare a new memory stream.
   MemoryStream^ userInput;

private:

   // Save the content of RichTextBox1 to the memory stream, 
   // appending a LineFeed character.  
   void Button1_Click( Object^ /*sender*/, EventArgs^ /*e*/ )
   {
      RichTextBox1->SaveFile( userInput, RichTextBoxStreamType::PlainText );
      userInput->WriteByte( 13 );
      
      // Display the entire contents of the stream,
      // by setting its position to 0, to RichTextBox2.
      userInput->Position = 0;
      RichTextBox2->LoadFile( userInput, RichTextBoxStreamType::PlainText );
   }


   // Shows the use of a SaveFileDialog to save a MemoryStream to a file.
   void Button2_Click( Object^ /*sender*/, EventArgs^ /*e*/ )
   {
      
      // Set the properties on SaveFileDialog1 so the user is 
      // prompted to create the file if it doesn't exist 
      // or overwrite the file if it does exist.
      SaveFileDialog1->CreatePrompt = true;
      SaveFileDialog1->OverwritePrompt = true;
      
      // Set the file name to myText.txt, set the type filter
      // to text files, and set the initial directory to the
      // MyDocuments folder.
      SaveFileDialog1->FileName = "myText";
      // DefaultExt is only used when "All files" is selected from 
      // the filter box and no extension is specified by the user.
      SaveFileDialog1->DefaultExt = "txt";
      SaveFileDialog1->Filter = "Text files (*.txt)|*.txt|All files (*.*)|*.*";
      SaveFileDialog1->InitialDirectory = 
          Environment->GetFolderPath(Environment::SpecialFolder::MyDocuments);
      
      // Call ShowDialog and check for a return value of DialogResult.OK,
      // which indicates that the file was saved. 
      DialogResult result = SaveFileDialog1->ShowDialog();
      Stream^ fileStream;
      if ( result == DialogResult::OK )
      {
         fileStream = SaveFileDialog1->OpenFile();
         userInput->Position = 0;
         userInput->WriteTo( fileStream );
         fileStream->Close();
      }
   }
};

int main()
{
   Application::Run( gcnew Form1 );
}

using System;
using System.Drawing;
using System.IO;
using System.Windows.Forms;

public partial class Form1: Form
{
    internal RichTextBox RichTextBox1;
    internal Button Button1;
    internal RichTextBox RichTextBox2;
    internal Button Button2;
    internal SaveFileDialog SaveFileDialog1;

    public Form1() : base()
    {   
        this.RichTextBox1 = new RichTextBox();
        this.Button1 = new Button();
        this.RichTextBox2 = new RichTextBox();
        this.Button2 = new Button();
        this.SaveFileDialog1 = new SaveFileDialog();
        this.SuspendLayout();
        this.RichTextBox1.Location = new Point(24, 64);
        this.RichTextBox1.Name = "RichTextBox1";
        this.RichTextBox1.TabIndex = 0;
        this.RichTextBox1.Text = "Type something here.";
        this.Button1.Location = new Point(96, 16);
        this.Button1.Name = "Button1";
        this.Button1.Size = new Size(96, 24);
        this.Button1.TabIndex = 1;
        this.Button1.Text = "Save To Stream";
        this.Button1.Click += new EventHandler(Button1_Click);
        this.RichTextBox2.Location = new Point(152, 64);
        this.RichTextBox2.Name = "RichTextBox2";
        this.RichTextBox2.TabIndex = 3;
        this.RichTextBox2.Text = 
            "It will be added to the stream and appear here.";
        this.Button2.Location = new Point(104, 200);
        this.Button2.Name = "Button2";
        this.Button2.Size = new Size(88, 32);
        this.Button2.TabIndex = 4;
        this.Button2.Text = "Save Stream To File";
        this.Button2.Click += new EventHandler(Button2_Click);
        this.ClientSize = new Size(292, 266);
        this.Controls.Add(this.Button2);
        this.Controls.Add(this.RichTextBox2);
        this.Controls.Add(this.Button1);
        this.Controls.Add(this.RichTextBox1);
        this.Name = "Form1";
        this.Text = "Form1";
        this.ResumeLayout(false);
    }

    public static void Main()
    {
        Application.Run(new Form1());
    }

    // Declare a new memory stream.
    MemoryStream userInput = new MemoryStream();

    // Save the content of RichTextBox1 to the memory stream, 
    // appending a LineFeed character.  
    private void Button1_Click(Object sender, EventArgs e)
    {
        RichTextBox1.SaveFile(userInput, RichTextBoxStreamType.PlainText);
        userInput.WriteByte(13);

        // Display the entire contents of the stream,
        // by setting its position to 0, to RichTextBox2.
        userInput.Position = 0;
        RichTextBox2.LoadFile(userInput, RichTextBoxStreamType.PlainText);
    }

    // Shows the use of a SaveFileDialog to save a MemoryStream to a file.
    private void Button2_Click(Object sender, EventArgs e)
    {
        // Set the properties on SaveFileDialog1 so the user is 
        // prompted to create the file if it doesn't exist 
        // or overwrite the file if it does exist.
        SaveFileDialog1.CreatePrompt = true;
        SaveFileDialog1.OverwritePrompt = true;

        // Set the file name to myText.txt, set the type filter
        // to text files, and set the initial directory to the 
        // MyDocuments folder.
        SaveFileDialog1.FileName = "myText";
        // DefaultExt is only used when "All files" is selected from 
        // the filter box and no extension is specified by the user.
        SaveFileDialog1.DefaultExt = "txt";
        SaveFileDialog1.Filter = 
            "Text files (*.txt)|*.txt|All files (*.*)|*.*";
        SaveFileDialog1.InitialDirectory = 
            Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);

        // Call ShowDialog and check for a return value of DialogResult.OK,
        // which indicates that the file was saved. 
        DialogResult result = SaveFileDialog1.ShowDialog();
        Stream fileStream;

        if (result == DialogResult.OK)
        {
            // Open the file, copy the contents of memoryStream to fileStream,
            // and close fileStream. Set the memoryStream.Position value to 0 
            // to copy the entire stream. 
            fileStream = SaveFileDialog1.OpenFile();
            userInput.Position = 0;
            userInput.WriteTo(fileStream);
            fileStream.Close();
        }
    }
}

Imports System.Drawing
Imports System.IO
Imports System.Windows.Forms

Partial Public Class Form1
    Inherits Form

    Friend WithEvents RichTextBox1 As RichTextBox
    Friend WithEvents Button1 As Button
    Friend WithEvents RichTextBox2 As RichTextBox
    Friend WithEvents Button2 As Button
    Friend WithEvents SaveFileDialog1 As SaveFileDialog

    Public Sub New()
        MyBase.New()
        Me.RichTextBox1 = New RichTextBox
        Me.Button1 = New Button
        Me.RichTextBox2 = New RichTextBox
        Me.Button2 = New Button
        Me.SaveFileDialog1 = New SaveFileDialog
        Me.SuspendLayout()
        Me.RichTextBox1.Location = New Point(24, 64)
        Me.RichTextBox1.Name = "RichTextBox1"
        Me.RichTextBox1.TabIndex = 0
        Me.RichTextBox1.Text = "Type something here."
        Me.Button1.Location = New Point(96, 16)
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New Size(96, 24)
        Me.Button1.TabIndex = 1
        Me.Button1.Text = "Save To Stream"
        Me.RichTextBox2.Location = New Point(152, 64)
        Me.RichTextBox2.Name = "RichTextBox2"
        Me.RichTextBox2.TabIndex = 3
        Me.RichTextBox2.Text = "It will be added to the stream and appear here."
        Me.Button2.Location = New Point(104, 200)
        Me.Button2.Name = "Button2"
        Me.Button2.Size = New Size(88, 32)
        Me.Button2.TabIndex = 4
        Me.Button2.Text = "Save Stream To File"
        Me.ClientSize = New Size(292, 266)
        Me.Controls.Add(Me.Button2)
        Me.Controls.Add(Me.RichTextBox2)
        Me.Controls.Add(Me.Button1)
        Me.Controls.Add(Me.RichTextBox1)
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.ResumeLayout(False)

    End Sub

    Public Shared Sub Main()
        Application.Run(New Form1)
    End Sub

    ' Declare a new memory stream.
    Dim userInput As New MemoryStream

    ' Save the content of RichTextBox1 to the memory stream, appending
    'a LineFeed character.  
    Private Sub Button1_Click(ByVal sender As Object, _
        ByVal e As EventArgs) Handles Button1.Click
        RichTextBox1.SaveFile(userInput, RichTextBoxStreamType.PlainText)
        userInput.WriteByte(13)

        ' Display the entire contents of the stream,
        ' by setting its position to 0, to RichTextBox2.
        userInput.Position = 0
        RichTextBox2.LoadFile(userInput, RichTextBoxStreamType.PlainText)
    End Sub

    ' Shows the use of a SaveFileDialog to save a MemoryStream to a file.
    Private Sub Button2_Click(ByVal sender As Object, _
        ByVal e As EventArgs) Handles Button2.Click

        ' Set the properties on SaveFileDialog1 so the user is 
        ' prompted to create the file if it doesn't exist 
        ' or overwrite the file if it does exist.
        SaveFileDialog1.CreatePrompt = True
        SaveFileDialog1.OverwritePrompt = True

        ' Set the file name to myText.txt, set the type filter
        ' to text files, and set the initial directory to the 
        ' MyDocuments folder.
        SaveFileDialog1.FileName = "myText"
        ' DefaultExt is only used when "All files" is selected from 
        ' the filter box and no extension is specified by the user.
        SaveFileDialog1.DefaultExt = "txt"
        SaveFileDialog1.Filter = "Text files (*.txt)|*.txt|All files (*.*)|*.*"
        SaveFileDialog1.InitialDirectory = _
            Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments)

        ' Call ShowDialog and check for a return value of DialogResult.OK,
        ' which indicates that the file was saved. 
        Dim result As DialogResult = SaveFileDialog1.ShowDialog()
        Dim fileStream As Stream

        If (result = DialogResult.OK) Then
            ' Open the file, copy the contents of memoryStream to fileStream,
            ' and close fileStream. Set the memoryStream.Position value to 0 to 
            ' copy the entire stream. 
            fileStream = SaveFileDialog1.OpenFile()
            userInput.Position = 0
            userInput.WriteTo(fileStream)
            fileStream.Close()
        End If
    End Sub

End Class

Remarks

You can use this version of the LoadFile method to load the RichTextBox with data from an existing stream of data. The data that is loaded into the control replaces the entire contents of the RichTextBox control. This will cause the values of the Text and Rtf properties to change. You can use this method to load a file that has been previously opened into a data stream into the control for manipulation. If you want to save contents of the control back into the stream, you can use the SaveFile method that accepts a Stream object as a parameter.

This version of the LoadFile method also enables you to specify the type of data that is being loaded into the control. This feature enables you to use data streams that contain data other than rich text format (RTF) documents into the control.

Note

The LoadFile method will not open a file until a handle is created for the RichTextBox. Ensure that the control's handle is created before calling the LoadFile method.

Applies to

LoadFile(String, RichTextBoxStreamType)

Loads a specific type of file into the RichTextBox control.

public:
 void LoadFile(System::String ^ path, System::Windows::Forms::RichTextBoxStreamType fileType);

public void LoadFile (string path, System.Windows.Forms.RichTextBoxStreamType fileType);

member this.LoadFile : string * System.Windows.Forms.RichTextBoxStreamType -> unit

Public Sub LoadFile (path As String, fileType As RichTextBoxStreamType)

Parameters

path: String

The name and location of the file to load into the control.

fileType: RichTextBoxStreamType

One of the RichTextBoxStreamType values.

Exceptions

IOException

An error occurred while loading the file into the control.

ArgumentException

The file being loaded is not an RTF document.

Examples

The following code example opens a text file into the RichTextBox control. The example uses the OpenFileDialog class to display a dialog to request the file from the user. The code then loads that file into the RichTextBox control. The example uses this version of the LoadFile method to specify that the file be opened as an ASCII text file instead of the standard rich text format. This example requires that the code is placed in a Form class that has a RichTextBox control named richTextBox1.

public:
   void LoadMyFile()
   {
      // Create an OpenFileDialog to request a file to open.
      OpenFileDialog^ openFile1 = gcnew OpenFileDialog;
      
      // Initialize the OpenFileDialog to look for RTF files.
      openFile1->DefaultExt = "*.rtf";
      openFile1->Filter = "RTF Files|*.rtf";
      
      // Determine whether the user selected a file from the OpenFileDialog.
      if ( openFile1->ShowDialog() == System::Windows::Forms::DialogResult::OK &&
         openFile1->FileName->Length > 0 )
      {
         // Load the contents of the file into the RichTextBox.
         richTextBox1->LoadFile( openFile1->FileName, RichTextBoxStreamType::PlainText );
      }
   }

public void LoadMyFile()
{
   // Create an OpenFileDialog to request a file to open.
   OpenFileDialog openFile1 = new OpenFileDialog();

   // Initialize the OpenFileDialog to look for RTF files.
   openFile1.DefaultExt = "*.rtf";
   openFile1.Filter = "RTF Files|*.rtf";

   // Determine whether the user selected a file from the OpenFileDialog.
   if(openFile1.ShowDialog() == System.Windows.Forms.DialogResult.OK &&
      openFile1.FileName.Length > 0) 
   {
      // Load the contents of the file into the RichTextBox.
      richTextBox1.LoadFile(openFile1.FileName, RichTextBoxStreamType.PlainText);
   }
}

Public Sub LoadMyFile()
    ' Create an OpenFileDialog to request a file to open.
    Dim openFile1 As New OpenFileDialog()
    
    ' Initialize the OpenFileDialog to look for RTF files.
    openFile1.DefaultExt = "*.rtf"
    openFile1.Filter = "RTF Files|*.rtf"
    
    ' Determine whether the user selected a file from the OpenFileDialog.
    If (openFile1.ShowDialog() = System.Windows.Forms.DialogResult.OK) _
        And (openFile1.FileName.Length > 0) Then
        
        ' Load the contents of the file into the RichTextBox.
        richTextBox1.LoadFile(openFile1.FileName, _
            RichTextBoxStreamType.PlainText)
    End If
End Sub

Remarks

When loading a file with the LoadFile method, the contents of the file being loaded replace the entire contents of the RichTextBox control. This will cause the values of the Text and Rtf properties to change. You can use this method to load a previously created text or rich text format (RTF) document into the control for manipulation. If you want to save the file, you can use the SaveFile method.

You can use this version of the LoadFile method to specify the file type of the file being loaded. This feature enables you to load files other than RTF documents into the control.

Note

The LoadFile method will not open a file until a handle is created for the RichTextBox. Ensure that the control's handle is created before calling the LoadFile method.

Applies to

Dela via

RichTextBox.LoadFile Method

Definition

Overloads

LoadFile(String)

Parameters

Exceptions

Examples

Remarks

See also

Applies to

LoadFile(Stream, RichTextBoxStreamType)

Parameters

Exceptions

Examples

Remarks

See also

Applies to

LoadFile(String, RichTextBoxStreamType)

Parameters

Exceptions

Examples

Remarks

See also

Applies to

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