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GetWindowTextLength Reference in C#, VB.NET and VB6


Visual Basic 6 definition
Declare Function GetWindowTextLength Lib "user32.dll" Alias "GetWindowTextLengthA" (ByVal hWnd As Long) As Long

Visual Basic .NET definition
Declare Function GetWindowTextLength Lib "user32" Alias "GetWindowTextLengthA" (ByVal hwnd As Integer) As Integer

C# definition
[DllImport("user32", EntryPoint="GetWindowTextLength")] public static extern int GetWindowTextLengthA(int hwnd)


GetWindowTextLength returns the length in characters of a window's text. You can use this function in conjunction with GetWindowText to create a string just long enough to receive the text. However, this function does not include the terminating null character in the window's text in the character count. In some instances, this function might report a larger text length than actually exists; however, it will never report fewer than the actual number of characters. GetWindowTextLength does not work with controls owned by other programs. To get the window text length of these controls, use the WM_GETTEXTLENGTH message instead. GetWindowTextLength Retrieves the length of the title bar text for the specified window. System.Windows.Forms.Form.Text.Length

Return Value

If an error occured, the function returns 0 (use GetLastError to get the error code). If successful, the function returns the number of characters in the window's text, not including the terminating null character.


Further Information:

For further information on Windows API functions such as these, and how to use these API's in your C# and VB.NET applications, please refer to the book 'Network programming in .NET' (Buy at Amazon UK) (Buy at Amazon US)

Visual Basic 6 example source code

Provide a code example



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