未被捕获的例外＆＃39;例外＆＃39;带消息＆＃39; FPDF错误：不是JPEG文件

Question

// $ qus_img为空

//错误在fpdf.php文件中

public EmployeeTable Edit(int Oid)
{
     using (EmployeeEntities dc = new EmployeeEntities())
     {
         EmployeeTable emp = dc.EmployeeTables.Find(Oid);
         return emp;
     }         
}