LoadString(hDll,10005,str3,MAX_PATH);SetDlgItemText(IDC_BTN_TEST,str3);

void CMyTestDlg::OnBnClickedBtnTest()
{
	// TODO: 在此添加控件通知处理程序代码
		HMODULE hDll = NULL;
	CString strBtn ;
	GetDlgItemText(IDC_BTN_TEST,strBtn);
	if (strBtn == _T("Test"))
	{
		hDll = LoadLibrary(_T("Zh_cn.dll"));
	}
	else
	{
		hDll = LoadLibrary(_T("us_en.dll"));
	}
	if (hDll)
	{
		TCHAR str1[MAX_PATH];
		TCHAR str2[MAX_PATH];
		TCHAR str3[MAX_PATH];
		LoadString(hDll,10003,str1,MAX_PATH);
		LoadString(hDll,10004,str2,MAX_PATH);
		LoadString(hDll,10005,str3,MAX_PATH);

		SetDlgItemText(IDOK,str1);
		SetDlgItemText(IDCANCEL,str2);
		SetDlgItemText(IDC_BTN_TEST,str3);

		FreeLibrary(hDll);
		hDll = NULL;

	}
	else
	{
		AfxMessageBox(_T("加载语言库失败"));
		return;
	}
}