如何在网格视图中对记录进行排序？

大家好！



我正在尝试通过单击网格视图中任何列的标题对网格视图中的记录进行排序。我阅读了很多关于它的文章，并按照说明进行尝试。当我尝试将其放入代码时，会出现一条错误消息，指出对象引用未设置为对象的实例。



这是我的代码所在错误是。错误部分是Asterisks的行：

私有DataView Getdata（）

{

connection（）;

amicassaCon.Open（）;

DataSet dsMilestone = new DataSet（）;

string strSelectCmd =SELECT [milestone_code]，[milestone_name]，[order_no]，[milestone_status ] FROM里程碑;

SqlDataAdapter da = new SqlDataAdapter（strSelectCmd，amicassaCon）;

da.Fill（dsMilestone，里程碑）;

*** DataView dvMilestone = dsMilestone.Tables [milsetone]。DefaultView;

dvMilestone.Sort = ViewState [SortExpr]。ToString（）;

返回dvMilestone;



}

Hi guys!

I am trying to sort the records in my grid view by clicking the Header of any of the columns in my grid view. I read many articles about it and try them according to the instructions. When I tried to put it in codes, there is an error message saying "Object Reference not set to an instance of an object."

Here is my code where the error is. The error part is the line with Asterisks:
private DataView Getdata()
{
connection();
amicassaCon.Open();
DataSet dsMilestone = new DataSet();
string strSelectCmd = "SELECT[milestone_code],[milestone_name],[order_no],[milestone_status] FROM milestone ";
SqlDataAdapter da = new SqlDataAdapter(strSelectCmd, amicassaCon);
da.Fill(dsMilestone, "milestone");
***DataView dvMilestone = dsMilestone.Tables["milsetone"].DefaultView;
dvMilestone.Sort = ViewState["SortExpr"].ToString();
return dvMilestone;

}