C # Global Hotkey settings and form hotkey settings

1. Form Hotkey

First, you set the main form KeyPreview to True, which you can set directly in the property.
or set in the form load: this. KeyPreview = true;

Then add the form KeyDown event, as follows:

        Private void Frmmain_keydown (object  sender, KeyEventArgs e)

        {            if (e.alt && e.shift && e.control && e.keycode = = keys.s)            {                MessageBox.Show (" I pressed control +shift +alt +s");}        }

2. Global Hotkey Settings

Define API function Register Hotkey "Uninstall Hotkey"

I define the Apphotkey class here, all the code is as follows:

   Public classApphotkey {[DllImport ("Kernel32.dll")]         Public Static extern UINTGetLastError (); //If the function executes successfully, the return value is not 0. //If the function fails to execute, the return value is 0. To get the extended error message, call GetLastError. [DllImport ("user32.dll", SetLastError =true)]         Public Static extern BOOLRegisterHotKey (IntPtr hWnd,//the handle of the window to define the hotkey            intId//Define Hotkey ID (cannot be duplicated with other IDs)Keymodifiers Fsmodifiers,//identifies whether the hotkey will take effect when pressing ALT, Ctrl, Shift, Windows, and other keysKeys VK//defining the contents of a hotkey            ); [DllImport ("user32.dll", SetLastError =true)]         Public Static extern BOOLUnregisterhotkey (IntPtr hWnd,//handle of the window to cancel the hotkey            intId//the ID of the hotkey to cancel            ); //defines the name of the secondary key (converts the number to characters for easy memory, or removes the enumeration and uses the value directly)[Flags ()] Public enumkeymodifiers {None=0, Alt=1, Ctrl=2, Shift=4, WindowsKey=8        }        /// <summary>        ///Register Hotkey/// </summary>        /// <param name= "hwnd" >window Handle</param>        /// <param name= "hotkey_id" >Hotkey ID</param>        /// <param name= "Keymodifiers" >Key Combinations</param>        /// <param name= "key" >Hotkey</param>         Public Static voidRegKey (INTPTR hwnd,inthotkey_id, Keymodifiers keymodifiers, Keys key) {            Try            {                if(!RegisterHotKey (hwnd, HOTKEY_ID, Keymodifiers, key)) {                    if(Marshal.GetLastWin32Error () = =1409) {MessageBox.Show ("hot keys are occupied! "); }                    Else{MessageBox.Show ("Register Hotkey failed! "); }                }            }            Catch(Exception) {}}/// <summary>        ///Logout Hotkey/// </summary>        /// <param name= "hwnd" >window Handle</param>        /// <param name= "hotkey_id" >Hotkey ID</param>         Public Static voidUnregkey (INTPTR hwnd,inthotkey_id) {            //Logout hotkey setting with ID number hotkey_idUnregisterhotkey (hwnd, hotkey_id); }    }

Rewrite the form's WndProc function, register the hotkey when the window is created, destroy the hotkey when the window is destroyed, and the code is as follows:

  　　     Private Const intWm_hotkey =0x312;//window Message-Hotkey        Private Const intWm_create =0x1;//window messages-Create        Private Const intWm_destroy =0x2;//window Message-Destroy        Private Const intSpace =0x3572;//Hotkey ID        protected Override voidWndProc (refMessage m) {            Base. WndProc (refm); Switch(m.msg) { CaseWm_hotkey://window message-Hotkey ID                    Switch(M.wparam.toint32 ()) { CaseSpace://Hotkey IDMessageBox.Show ("I pressed the control +shift +alt +s");  Break; default:                             Break; }                     Break;  CaseWm_create://window messages-CreateApphotkey.regkey (Handle, Space, AppHotKey.KeyModifiers.Ctrl | AppHotKey.KeyModifiers.Shift |AppHotKey.KeyModifiers.Alt, KEYS.S);  Break;  CaseWm_destroy://window Message-DestroyApphotkey.unregkey (Handle, Space);//destroying Hotkeys                     Break; default:                     Break; }        }

C # Global Hotkey settings and form hotkey settings