第一种方法:用out
但GetList方法刚开始这样写:
comnameList = new List<string>();
comipList = new List<string>();
comcomList = new List<string>();- private void winTest_Loaded(object sender, RoutedEventArgs e)
- {
- List<String> comnameList = new List<string>();
- List<String> comipList = new List<string>();
- List<String> comcomList = new List<string>();
- GetList(out comnameList, out comipList, out comcomList);
- }
- public void GetList(out List<string> comnameList, out List<string> comipList, out List<string> comcomList)
- {
- comnameList = new List<string>();
- comipList = new List<string>();
- comcomList = new List<string>();
- string connStr = ConfigurationManager.ConnectionStrings["dbConnStr"].ConnectionString;
- using (SqlConnection conn = new SqlConnection(connStr))
- {
- conn.Open();
- using (SqlCommand cmd = conn.CreateCommand())
- {
- cmd.CommandText = "SELECT * FROM dbo.T_AreaFull WHERE AreaPid = 0";
- SqlDataReader reader = cmd.ExecuteReader();
- while (reader.Read())
- {
- comnameList.Add(String.Format("{0}", reader[0]));
- comipList.Add(String.Format("{0}", reader[1]));
- comcomList.Add(String.Format("{0}", reader[2]));
- }
- }
- }
- }
复制代码 第二种方法:像楼上说的改用ref 就不报错了
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