Question

我尝试使用switch使用DataTable访问SqlDataAdapter中的数据，但不确定如何使用switch语句访问字段。

以下是我的开始：

  SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["myconnectionstring"].ConnectionString);
  SqlDataAdapter da = new SqlDataAdapter("SELECT NAME, DEPARTMENT, LOCATION from MyTable WHERE ID =  @ID", con);

  DataTable dt= new DataTable();
  da.SelectCommand.Parameters.AddWithValue("@ID", int.Parse(ID));
  da.Fill(dt);

  DataRow row = dt.Rows[0];

这里是我迷路的地方，我确信下面的switch语句不是正确的语法

switch (dt[0].Location)
   {
       case 1:
       lblStage.Text = dt[0].Location.ToString() + " - It has been completed.";
        break;
   }

Answer 1

您必须在switch语句中执行Convert.ToInt32(dt[0]["Location"].ToString())

Answer 2

DataRow row = dt.Rows[0];
int temp = Convert.ToInt32(row["Location"].ToString());

switch (temp)
{
    case 1:
    lblStage.Text = temp.ToString() + " has been completed";
    break;

    case 2:
    lblStage.Text = temp.ToString() + " has been completed";
    break;

    default:
    // Perform altrenative, default logic
    break;
}

在C＃中使用switch语句并从SqlDataAdapter读取数据

2 个答案: