C # winform implements a simple virtual keyboard

There are two key technical points:

1. Set the form of the keyboard to the floating toolbar form. You only need to rewrite the createparams of the form so that the form does not obtain the focus,CodeAs follows:

# Region Specify the current form as a floating toolbar form
Public Enum Windowstyles: Uint
{
Ws_overlapped = Zero X 00000000 ,
Ws_popup = Zero X 80000000 ,
Ws_child = Zero X 40000000 ,
Ws_minimize = Zero X 20000000 ,
Ws_visible = Zero X 10000000 ,
Ws_disabled = Zero X 08000000 ,
Ws_clipsiblings = Zero X 04000000 ,
Ws_clipchildren = Zero X 02000000 ,
Ws_maximize = Zero X 01000000 ,
Ws_border = Zero X 00800000 ,
Ws_dlgframe = Zero X 00400000 ,
Ws_vscroll = Zero X 00200000 ,
Ws_hscroll = Zero X 00100000 ,
Ws_sysmenu = Zero X 00080000 ,
Ws_thickframe = Zero X 00040000 ,
Ws_group = Zero X 00020000 ,
Ws_tabstop = Zero X 00010000 ,

ws_minimizebox = 0x00020000 ,
ws_maximizebox = 0x00010000 ,

ws_caption = ws_border | ws_dlgframe,
ws_tiled = ws_overlapped,
ws_iconic = ws_minimize,
ws_sizebox = ws_thickframe,
ws_tiledwindow = ws_overlappedwindow,

Ws_overlappedwindow = ws_overlapped | ws_caption | ws_sysmenu | ws_thickframe | ws_minimizebox | ws_maximizebox,
Ws_popupwindow = ws_popup | ws_border | ws_sysmenu,
Ws_childwindow = ws_child,

// Extended window styles

Ws_ex_dlgmodalframe = Zero X 00000001 ,
Ws_ex_noparentnotify = Zero X 00000004 ,
Ws_ex_topmost = Zero X 00000008 ,
Ws_ex_acceptfiles = Zero X 00000010 ,
Ws_ex_transparent = Zero X 00000020 ,

// # If (winver> = 0x0400)

Ws_ex_mdichild = Zero X 00000040 ,
Ws_ex_toolwindow = Zero X 00000080 ,
Ws_ex_windowedge = Zero X 00000100 ,
Ws_ex_clientedge = Zero X 00000200 ,
Ws_ex_contexthelp = Zero X 00000400 ,

Ws_ex_right = Zero X 00001000 ,
Ws_ex_left = Zero X 00000000 ,
Ws_ex_rtlreading = Zero X 00002000 ,
Ws_ex_ltrreading = Zero X 00000000 ,
Ws_ex_leftscrollbar = Zero X 00004000 ,
Ws_ex_rightscrollbar = Zero X 00000000 ,

ws_ex_controlparent = 0x00010000 ,
ws_ex_staticedge = 0x00020000 ,
ws_ex_appwindow = 0x00040000 ,

Ws_ex_overlappedwindow = (ws_ex_javaswedge | ws_ex_clientedge ),
Ws_ex_palettewindow = (ws_ex_shortwedge | ws_ex_toolwindow | ws_ex_topmost ),

//# Endif/* winver> = 0x0400 */

//# If (win32winnt> = 0x0500)

Ws_ex_layered =Zero X 00080000,

//# Endif/* win32winnt> = 0x0500 */

// # If (winver> = 0x0500)

Ws_ex_noinheritlayout = Zero X 00100000 , // Disable inheritence of processing ing by children
Ws_ex_layoutrtl = Zero X 00400000 , // Right to left grouping ing

//# Endif/* winver> = 0x0500 */

//# If (win32winnt> = 0x0500)

Ws_ex_composited =Zero X 02000000,
Ws_ex_noactivate =Zero X 08000000

// # Endif/* win32winnt> = 0x0500 */

}
Protected Override Createparams
{
Get
{
Createparams ret = Base . Createparams;
Ret. Style = ( Int ) Windowstyles. ws_thickframe | ( Int ) Windowstyles. ws_child;
Ret. exstyle | = ( Int ) Windowstyles. ws_ex_noactivate | ( Int ) Windowstyles. ws_ex_toolwindow;
Ret. x = This . Location. X;
Ret. Y = This . Location. Y;
Return RET;
}
}

# Endregion 

2. Use the sendkeys method to send the key to the applicationProgram. See how to use sendkeys.