需要的頭文件和庫
#include <imm.h>
#pragma comment (lib ,"imm32.lib")
//切換英文輸入法,00000409代表的是系統自帶的美式鍵盤
HKL hkl = LoadKeyboardLayout(_T("00000409"), KLF_ACTIVATE);
PostMessage(hWnd, WM_INPUTLANGCHANGEREQUEST, (WPARAM)TRUE, (LPARAM)hkl);
//切換中文輸入法,00000804代表的是智能中文輸入法,比如搜狗輸入法之類的
hkl = LoadKeyboardLayout(_T("00000804"), KLF_ACTIVATE);
PostMessage(hWnd, WM_INPUTLANGCHANGEREQUEST, (WPARAM)TRUE, (LPARAM)hkl);