C#中的小问题 - .NET技术 / C#

一个类中定义了一个getUserlist()方法，用到了连接数据库，在另一个类中调用，出现错误提示错误 1 “Lib.AdminUser.getUserName(string)”: 并非所有的代码路径都返回值 C:\Documents and Settings\Administrator\桌面\家庭理财小助手\Lib\AdminUser.cs 38 32 Lib[/color]代码如下：public static UserInfo getUserName(string name)
  {
  OleDbConnection conn = new OleDbConnection(connString);
  try
  {
  string comString = "SELECT [姓名], [密码], [权限] from 用户 where 姓名='" + name + "'";
  OleDbCommand Cmand = new OleDbCommand(comString, conn);
  conn.Open();
  OleDbDataReader dataReader = Cmand.ExecuteReader();
  if (dataReader.FieldCount > 0)
  {
  string _name = dataReader.GetString(0);
  string mima = dataReader.GetString(1);
  UserRight userRight = (UserRight)dataReader.GetInt32(2);

  UserInfo userInfo = new UserInfo(_name, mima, userRight);
  return userInfo;
  }

  }
  catch (Exception)
  {
  return null;

  }
  finally
&nbs