c# - Checking multiple session variables if they are null

Question

I am using the following to check a number of session variables:

if(MySession.Current.mpr != null && MySession.Current.mpr1 != null && MySession.Current.mpr2 != null
  && MySession.Current.mpr3 != null && MySession.Current.mip != null && MySession.Current.vr != null)
{
  ....
}

It does not work! I know one of the variables is not null. Any suggestions?

Answer 1

if如果所有变量都不是，则您的语句仅写入块内部null。如果一个变量不为空，要进入内部，请使用 ors||而不是 and &&：

if(MySession.Current.mpr != null || MySession.Current.mpr1 != null || MySession.Current.mpr2 != null
  || MySession.Current.mpr3 != null || MySession.Current.mip != null || MySession.Current.vr != null)
{
  ....
}