linq 像空字符串

Question

var list = (from i in _dataContext.aspnet_Users.Include("aspnet_Membership")  where i.UserName.Contains(userName)  select i ).ToList();

如果 userName="" 那么什么都不会返回。如果空字符串然后返回所有记录，我该怎么做？

Answer 1

做:

  var list = 
      (from i in _dataContext.aspnet_Users.Include("aspnet_Membership") 
        where string.IsNullOrEmpty(userName)
               || i.UserName.Contains(userName)  
       select i ).ToList();