新手求助！！关于C++开发Windows程序！

#include <windows.h>
#include <WindowsX.h>
#include "resource1.h"
#include "library.h"
class my_app : public dialog { // my_app继承dialog
public:
my_app(LPCWSTR src) : dialog(src) {}
private:
BOOL OnInitDialog(HWND hDlg, HWND hwndFocus, LPARAM lParam，) {
SetWindowText(GetDlgItem(hDlg, IDC_LABEL), L"Hello World"); // 打印hello world
return TRUE;
}
private:
int do_proc(HWND hDlg, UINT uMsg, WPARAM wParam, LPARAM lParam) {
switch (uMsg) {
HANDLE_MSG(hDlg, WM_INITDIALOG, OnInitDialog);
}
return dialog::do_proc(hDlg, uMsg, wParam, lParam);
}
};

int WINAPI WinMain(__in HINSTANCE hInstance, __in_opt HINSTANCE hPrevInstance, __in_opt LPSTR lpCmdLine, __in int nShowCmd)
{
my_app main_dialog(L"MainDialog"); // 创建app对象
main_dialog.open(); // 打开对话框
}