Question

我的网格视图是手动数据绑定（其他工作）。读取其他线程我必须管理自己的排序事件。

点击列以在我的网页上对其进行排序时，我收到错误：

“对象引用未设置为对象的实例。”

这样做的结果是该表为null，但我不明白为什么它为null。

有什么想法吗？

protected void GridView1_Sorting(object sender, GridViewSortEventArgs e)
{
    DataTable table = GetData();
    table.DefaultView.Sort = e.SortExpression + " " + SetSortDirection(e.SortDirection.ToString());
    GridView1.DataSource = table;
    GridView1.DataBind();
}

protected string SetSortDirection(string currentsortDirection)
{
    string sortDirection;
    if (currentsortDirection == "Ascending")
    {
        sortDirection = "Descending";
    }
    else
    {
        sortDirection = "Ascending";
    }
    return sortDirection;
}

编辑：

public DataTable GetData()
{
    SqlConnection conn = new SqlConnection(@"Data Source=.\SQLEXPRESS;Initial Catalog=DatabaseName;Integrated Security=True");
    conn.Open();
    string query = "SELECT * FROM tablex WHERE Property='" + Request.QueryString["xxx"] + "'";
    SqlCommand cmd = new SqlCommand(query, conn);

    DataTable dt = new DataTable();
    dt.Load(cmd.ExecuteReader());
    return dt;
}

感谢。

Answer 1

 DataTable table = BuildInfo_GridView.DataSource as DataTable;

像这样你不会得到数据源你已经绑定的回调结束查询来获取数据，或者当你绑定数据时只将它存储在视图状态并获取它

Answer 2

Save your sort order in view state
if (ViewState["sortOrder"] != null)
            {
                ViewState["sortExpression"] = e.SortExpression;
                if (ViewState["sortOrder"].ToString().ToUpper() == "ASCENDING")
                {
                    e.SortDirection = SortDirection.Descending;
                    ViewState["sortOrder"] = SortDirection.Descending.ToString();
                }
                else
                {
                    e.SortDirection = SortDirection.Ascending;
                    ViewState["sortOrder"] = SortDirection.Ascending.ToString();
                }
            }
            else
            {
                ViewState["sortExpression"] = e.SortExpression;
                ViewState["sortOrder"] = e.SortDirection.ToString();
            }

手动网格视图排序

2 个答案: