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RichTextBox::LoadFile Method (Stream, RichTextBoxStreamType)

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

Namespace:  System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

public:
void LoadFile(
	Stream^ data, 
	RichTextBoxStreamType fileType
)

Parameters

data
Type: System.IO::Stream

A stream of data to load into the RichTextBox control.

fileType
Type: System.Windows.Forms::RichTextBoxStreamType

One of the RichTextBoxStreamType values.

ExceptionCondition
IOException

An error occurred while loading the file into the control.

ArgumentException

The file being loaded is not an RTF document.

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.

NoteNote

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.

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 is 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 );
}
The following code example demonstrates using the 
RichTextBox.SaveFile and RichTextBox.LoadFile methods with streams.
It also demonstrates using the FileDialog.FileName, 
SaveFileDialog.CreatePrompt, SaveFileDialog.OverwritePrompt, and 
TextBox.Click members. This is a complete example that is ready to run when you copy it to your project.

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1
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