The entire process of using the system hotkey in the C # program.

1. First introduce system. runtime. interopservices

Using system. runtime. interopservices;

2. Declare two API functions in the class. Their positions are the same as those of the class member variables.

[System. runtime. interopservices. dllimport ("user32.dll")] // declare an API Function Public static extern bool registerhotkey ( Intptr hwnd, // handle to window Int ID, // Hot Key Identifier Uint fsmodifiers, // key-modifier options Keys VK // virtual-key code ); [System. runtime. interopservices. dllimport ("user32.dll")] // declare an API Function Public static extern bool unregisterhotkey ( Intptr hwnd, // handle to window Int ID // Hot Key Identifier );

3. Define an enumeration of keymodifiers to enable a key combination.

Public Enum keymodifiers { None = 0, Alt = 1, Control = 2, Shift = 4, Windows = 8 }

4. register the system hotkey in the class Constructor

For example, the following example registers four hotkeys:

Public mainform () { Initializecomponent (); Registerhotkey (handle, 100, 2, keys. Left); // hotkey 1: Control + cursor left arrow Registerhotkey (handle, 200, 2, keys. Right); // hotkey 1: Control + right arrow of the cursor Registerhotkey (handle, 300, 2, keys. Up); // hotkey 1: Control + cursor up arrow Registerhotkey (handle, 400, 2, keys. Down); // hotkey 1: Control + cursor down arrow ....; }

5. Rewrite the wndproc () method and call the process by monitoring system messages.

Example:

Protected override void wndproc (ref message m) // monitor Windows messages { Const int wm_hotkey = 0x0312; // if the value of M. MSG is 0x0312, the user presses the hot key. Switch (M. msg) { Case wm_hotkey: Processhotkey (m); // call the processhotkey () function when the hot key is pressed. Break; } Base. wndproc (ref m); // transmits the system message from the wndproc of the parent class. }

5. Needless to say, we need to implement the processhotkey function:

// Call this function when you press the specified key. Private void processhotkey (message m) { Intptr id = M. wparam; // intptr indicates the platform-specific type of the pointer or handle. // MessageBox. Show (Id. tostring ()); String SID = ID. tostring (); Switch (SID) { Case "100": decresevolumnb (); break; // press the Control + left arrow of the cursor to call the decresevolumnb () function (); Case "200": addvolumnb (); break; // Press Control + the right arrow of the cursor to call the addvolumnb () function () Case "300": // press the Control + cursor arrow to display the form This. Visible = true; Break; Case "400": // press the Control + cursor down arrow to hide the form This. Visible = false; Break; } }

Obviously, the following functions are implemented respectively: decresevolumnb (); and addvolumnb.

6. Don't forgetProgramCancel hotkey registration upon exit

Private void mainform_formclosing (Object sender, formclosingeventargs E) { Unregisterhotkey (handle, 100); // uninstall the 1st shortcut keys Unregisterhotkey (handle, 200); // contains 2nd shortcut keys Unregisterhotkey (handle, 300); // uninstall the 3rd shortcut keys Unregisterhotkey (handle, 400); // contains 4th shortcut keys }

The above is the whole process of using the system hotkey in the C # program.