C# Signature:
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool FlashWindowEx(ref FLASHWINFO pwfi);
User-Defined Types:
[StructLayout(LayoutKind.Sequential)]
public struct FLASHWINFO
{
public UInt32 cbSize;
public IntPtr hwnd;
public UInt32 dwFlags;
public UInt32 uCount;
public UInt32 dwTimeout;
}
public enum FlashWindow : uint
{
/// <summary>
/// Stop flashing. The system restores the window to its original state.
/// </summary>
FLASHW_STOP = 0,
/// <summary>
/// Flash the window caption
/// </summary>
FLASHW_CAPTION = 1,
/// <summary>
/// Flash the taskbar button.
/// </summary>
FLASHW_TRAY = 2,
/// <summary>
/// Flash both the window caption and taskbar button.
/// This is equivalent to setting the FLASHW_CAPTION | FLASHW_TRAY flags.
/// </summary>
FLASHW_ALL = 3,
/// <summary>
/// Flash continuously, until the FLASHW_STOP flag is set.
/// </summary>
FLASHW_TIMER = 4,
/// <summary>
/// Flash continuously until the window comes to the foreground.
/// </summary>
FLASHW_TIMERNOFG = 12
}
Notes:
Tips & Tricks:
Please add some!
Sample Code:
/// <summary>
/// Flashes a window
/// </summary>
/// <param name="hWnd">The handle to the window to flash</param>
/// <returns>whether or not the window needed flashing</returns>
public static bool FlashWindowEx(IntPtr hWnd)
{
FLASHWINFO fInfo = new FLASHWINFO();
fInfo.cbSize = Convert.ToUInt32(Marshal.SizeOf(fInfo));
fInfo.hwnd = hWnd;
fInfo.dwFlags = FLASHW_ALL;
fInfo.uCount = UInt32.MaxValue;
fInfo.dwTimeout = 0;
return FlashWindowEx(ref fInfo);
}
...
/// Minor adjust to the code above
/// <summary>
/// Flashes a window until the window comes to the foreground
/// Receives the form that will flash
/// </summary>
/// <param name="hWnd">The handle to the window to flash</param>
/// <returns>whether or not the window needed flashing</returns>
public static bool FlashWindowEx(Form frm)
{
IntPtr hWnd = frm.Handle;
FLASHWINFO fInfo = new FLASHWINFO();
fInfo.cbSize = Convert.ToUInt32(Marshal.SizeOf(fInfo));
fInfo.hwnd = hWnd;
fInfo.dwFlags = FLASHW_ALL | FLASHW_TIMERNOFG;
fInfo.uCount = UInt32.MaxValue;
fInfo.dwTimeout = 0;
return FlashWindowEx(ref fInfo);
}
Example Usage/Link:
Flash Window in Taskbar via Win32 FlashWindowEx:
http://pietschsoft.com/post/2009/01/26/CSharp-Flash-Window-in-Taskbar-via-Win32-FlashWindowEx.aspx
Alternative Managed API:
Do you know one? Please contribute it!
VB Code:
Private Declare Function FlashWindowEx Lib "User32.dll" (ByRef fwInfo As FLASHWINFO) As Boolean
' As defined by: http://msdn.microsoft.com/en-us/library/ms679347(v=vs.85).aspx
Public Enum FlashWindowFlags As UInteger
' Stop flashing. The system restores the window to its original state.
FLASHW_STOP = 0
' Flash the window caption.
FLASHW_CAPTION = 1
' Flash the taskbar button.
FLASHW_TRAY = 2
' Flash both the window caption and taskbar button.
' This is equivalent to setting the FLASHW_CAPTION | FLASHW_TRAY flags.
FLASHW_ALL = 3
' Flash continuously, until the FLASHW_STOP flag is set.
FLASHW_TIMER = 4
' Flash continuously until the window comes to the foreground.
FLASHW_TIMERNOFG = 12
End Enum
Public Structure FLASHWINFO
Public cbSize As UInteger
Public hwnd As UInteger
Public dwFlags As FlashWindowFlags
Public uCount As UInteger
Public dwTimeout As UInteger
End Structure
Public Function FlashWindow(ByRef frm As Windows.Forms.Form) As Boolean
Return FlashWindow(frm, True, True, 5)
End Function
Public Function FlashWindow(ByRef frm As Windows.Forms.Form, ByVal FlashTitleBar As Boolean, ByVal FlashTray As Boolean) As Boolean
Return FlashWindow(frm, FlashTitleBar, FlashTray, 5)
End Function
Public Function FlashWindow(ByRef frm As Windows.Forms.Form, ByVal FlashCount As Integer) As Boolean
Return FlashWindow(frm, True, True, FlashCount)
End Function
Public Function FlashWindow(ByRef frm As Windows.Forms.Form, ByVal FlashTitleBar As Boolean, ByVal FlashTray As Boolean, ByVal FlashCount As Integer) As Boolean
If frm Is Nothing Then Return False
If frm.IsDisposed Then Return False
If frm.Handle = 0 Then Return False
Try
Dim fwi As New FLASHWINFO
With fwi
.hwnd = frm.Handle
If FlashTitleBar Then .dwFlags = .dwFlags Or FlashWindowFlags.FLASHW_CAPTION
If FlashTray Then .dwFlags = .dwFlags Or FlashWindowFlags.FLASHW_TRAY
.uCount = FlashCount
If FlashCount = 0 Then .dwFlags = .dwFlags Or FlashWindowFlags.FLASHW_TIMERNOFG
.dwTimeout = 0 ' Use the default cursor blink rate.
.cbSize = System.Runtime.InteropServices.Marshal.SizeOf(fwi)
End With
Return FlashWindowEx(fwi)
Catch
Return False
End Try
End Function
#End Region
