何时使用Exception(When to use Exception)

 我有一个表单或页面以及分配给使用此页面的用户的一些权限（保存，修改，删除等），假设此用户仅具有“保存”和“修改”权限。 
 
 当用户点击他没有特权的删除按钮时，我想向他显示一条消息，告诉他他没有这个特权，我的代码怎么样？ 
 
 选项1 
 
If(loggedUser.Privileges.Contains(PrivilegeTypes.Delete) == false)
{
     MessageBox.Show("You dont have delete privilege!");
     // Log that user tried to delete without permission etc
     return;
}
 
 选项2 
 
try
{
     If(loggedUser.Privileges.Contains(PrivilegeTypes.Delete) == false)
     {
         // Throw custom exception
         throw new UngrantedPrivilegeException(PrivilegeTypes.Delete, "Invalid privilege exception");
     }
}
catch (UngrantedPrivilegeException ex)
{
     if( ex.PrivilegeType == PrivilegeTypes.Delete) 
     {
          MessageBox.Show("You dont have delete privilege!");
          // Log that user tried to delete without permission etc
     }
}

I have a Form or Page and some privileges (Save, Modify, Delete etc.) assigned to a user that is using this page, let's assume this user only has Save and Modify privileges.
 
When user clicks Delete button, which he is not privileged to, I want to display a message to him to inform him that he doesnt have this privilege, how should my code look like?
 
Option 1
 
If(loggedUser.Privileges.Contains(PrivilegeTypes.Delete) == false)
{
     MessageBox.Show("You dont have delete privilege!");
     // Log that user tried to delete without permission etc
     return;
}
 
Option 2
 
try
{
     If(loggedUser.Privileges.Contains(PrivilegeTypes.Delete) == false)
     {
         // Throw custom exception
         throw new UngrantedPrivilegeException(PrivilegeTypes.Delete, "Invalid privilege exception");
     }
}
catch (UngrantedPrivilegeException ex)
{
     if( ex.PrivilegeType == PrivilegeTypes.Delete) 
     {
          MessageBox.Show("You dont have delete privilege!");
          // Log that user tried to delete without permission etc
     }
}

原文：https://stackoverflow.com/questions/20858284