C++ 打开记事本 并写入文件 （能打开可是写不进去求解答）

#include <iostream> #include <windows.h> #include <fstream> int main () {   HWND hwnd; hwnd = ::FindWindow ("Notepad","无标题-记事本"); if (hwnd == NULL)  {  ::ShellExecute(hwnd,"open","a.txt",NULL,NULL,SW_SHOWNORMAL);  Sleep(1000); char str[12] = "1";  ::SendMessage (hwnd, WM_SETTEXT, 0,(LPARAM)str); //向EDIT写入文字 } }