You can use this property to restrict the length of text entered in the control for values such as postal codes and telephone numbers, or to restrict the length of text entered when the data is to be entered in a database. You can limit the text entered into the control to the maximum length of the corresponding field in the database.

Note:
In code, you can set the value of the Text property to a value that has a length greater than the value specified by the MaxLength property. This property only affects text entered into the control at run time.

Windows NT 4.0, Windows 2000, Windows 2000 Professional, Windows 2000 Server, Windows 2000 Advanced Server, Windows XP Home Edition, Windows XP Professional x64 Edition, Windows Server 2003 Platform Note:

For single line text box controls, if the MaxLength property is set to 0, the maximum number of characters the user can enter is 2147483646 or an amount based on available memory, whichever is smaller. For multiline text box controls, the maximum number of characters the user can enter is 4294967295 or an amount based on available memory, whichever is smaller.

Windows Millennium Edition Platform Note:

For single line text box controls, if the MaxLength property is set to 0, the maximum number of characters the user can enter is 32,766 or an amount based on available memory, whichever is smaller. For multiline text box controls, the maximum number of characters the user can enter is 65,535 or an amount based on available memory, whichever is smaller.

The following code example uses the derived class, TextBox, to create a text box that is used to accept a password. This example uses the CharacterCasing property to change all characters typed to uppercase and the MaxLength property to restrict the password length to eight characters. This example also uses the TextAlign property to center the password in the TextBox control.

Public Sub CreateMyPasswordTextBox()
    ' Create an instance of the TextBox control.
    Dim textBox1 As New TextBox()
    ' Set the maximum length of text in the control to eight.
    textBox1.MaxLength = 8
    ' Assign the asterisk to be the password character.
    textBox1.PasswordChar = "*"c
    ' Change all text entered to be uppercase.
    textBox1.CharacterCasing = CharacterCasing.Upper
    ' Align the text in the center of the TextBox control.
    textBox1.TextAlign = HorizontalAlignment.Center
End Sub

public void CreateMyPasswordTextBox()
 {
    // Create an instance of the TextBox control.
    TextBox textBox1 = new TextBox();
    // Set the maximum length of text in the control to eight.
    textBox1.MaxLength = 8;
    // Assign the asterisk to be the password character.
    textBox1.PasswordChar = '*';
    // Change all text entered to be uppercase.
    textBox1.CharacterCasing = CharacterCasing.Upper;
    // Align the text in the center of the TextBox control.
    textBox1.TextAlign = HorizontalAlignment.Center;
 }

public:
   void CreateMyPasswordTextBox()
   {
      // Create an instance of the TextBox control.
      TextBox^ textBox1 = gcnew TextBox;
      // Set the maximum length of text in the control to eight.
      textBox1->MaxLength = 8;
      // Assign the asterisk to be the password character.
      textBox1->PasswordChar = '*';
      // Change all text entered to be uppercase.
      textBox1->CharacterCasing = CharacterCasing::Upper;
      // Align the text in the center of the TextBox control.
      textBox1->TextAlign = HorizontalAlignment::Center;
   }

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC

.NET Framework

.NET Compact Framework

Reference