C# Signature:

/// <summary>
///     Changes the text of the specified window's title bar (if it has one). If the specified window is a control, the
///     text of the control is changed. However, SetWindowText cannot change the text of a control in another application.
///     <para>
///     Go to https://msdn.microsoft.com/en-us/library/windows/desktop/ms633546%28v=vs.85%29.aspx for more
///     information
///     </para>
/// </summary>
/// <param name="hwnd">C++ ( hWnd [in]. Type: HWND )<br />A handle to the window or control whose text is to be changed.</param>
/// <param name="lpString">C++ ( lpString [in, optional]. Type: LPCTSTR )<br />The new title or control text.</param>
/// <returns>
///     If the function succeeds, the return value is nonzero. If the function fails, the return value is zero.<br />
///     To get extended error information, call GetLastError.
/// </returns>
/// <remarks>
///     If the target window is owned by the current process, <see cref="SetWindowText" /> causes a WM_SETTEXT message to
///     be sent to the specified window or control. If the control is a list box control created with the WS_CAPTION style,
///     however, <see cref="SetWindowText" /> sets the text for the control, not for the list box entries.<br />To set the
///     text of a control in another process, send the WM_SETTEXT message directly instead of calling
///     <see cref="SetWindowText" />. The <see cref="SetWindowText" /> function does not expand tab characters (ASCII code
///     0x09). Tab characters are displayed as vertical bar(|) characters.<br />For an example go to
///     <see cref="!:https://msdn.microsoft.com/en-us/library/windows/desktop/ms644928%28v=vs.85%29.aspx#sending">
///     Sending a
///     Message.
///     </see>
/// </remarks>
[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
public static extern bool SetWindowText(IntPtr hwnd, String lpString);

VB.Net Signature:

<DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
Private Shared Function SetWindowText(ByVal hwnd As IntPtr, ByVal lpString As String) As Boolean
End Function

VB Signature:

Declare Auto Function SetWindowText Lib "user32" (ByVal hWnd As IntPtr, ByVal lpstring As String) As Boolean

User-Defined Types:

None.

Notes:

The handle used cannot be used to make a Form from Form.FromHandle() or from Control.FromHandle().

Tips & Tricks:

Please add some!

C# Sample Code:

SetWindowText(Process.GetCurrentProcess().MainWindowHandle, "Amazing!");

Alternative Managed API:

Do you know one? Please contribute it!