GridView和updatepanel - 不要改变视图

Question

我需要帮助updatepanel。 我有一个这样的网格：

<asp:UpdatePanel ID="UpdatePanel1" runat="server" EnableViewState="false" UpdateMode="Conditional"> 
     <Triggers> 
      <asp:AsyncPostBackTrigger ControlID="DropDownList2" EventName="SelectedIndexChanged" /> 
     </Triggers> 
     <ContentTemplate> 
      <asp:TextBox ID="TextBox2" runat="server" TextMode="MultiLine" Width="294px"></asp:TextBox> 
      <br /> 
      <br /> 
      <asp:GridView ID="GridView1" runat="server" AllowSorting="True" 
       BackColor="#FFFFCC" Width="100%" AutoGenerateSelectButton="True" 
       BorderWidth="1px" EnableSortingAndPagingCallbacks="True" 
       onselectedindexchanging="GridView1_SelectedIndexChanging" 
       onselectedindexchanged="GridView1_SelectedIndexChanged"> 
       <Columns> 
        <asp:BoundField DataField="nazwa_dysku" HeaderText="Nazwa Dysku" 
         SortExpression="nazwa_dysku" /> 
         <asp:BoundField DataField="folder" HeaderText="Folder" 
         SortExpression="folder" /> 
         <asp:BoundField DataField="nazwa_pliku" HeaderText="Nazwa Pliku" 
         SortExpression="nazwa_pliku" /> 
         <asp:BoundField DataField="czas_trwania" HeaderText="Czas trwania" 
         SortExpression="czas_trwania" /> 
         <asp:BoundField DataField="rozmiar" HeaderText="Rozmiar" 
         SortExpression="rozmiar" /> 
         <asp:BoundField DataField="data_utworzenia" HeaderText="Data utworzenia" 
         SortExpression="data_utworzenia" /> 
         <asp:BoundField DataField="data_modyfikacji" HeaderText="Data modyfikacji" 
         SortExpression="data_modyfikacji" /> 
         <asp:BoundField DataField="sciezka" HeaderText="Lokalizacja" 
         SortExpression="sciezka" /> 
       </Columns> 
       <HeaderStyle BackColor="#9A6E71" Font-Size="Medium" /> 
       <SelectedRowStyle BackColor="Red" /> 
      </asp:GridView> 
     </ContentTemplate> 
     <Triggers> 
      <asp:AsyncPostBackTrigger ControlID="GridView1" EventName="SelectedIndexChanged" /> 
      <asp:AsyncPostBackTrigger ControlID="GridView1" EventName="SelectedIndexChanging" /> 
     </Triggers> 
    </asp:UpdatePanel> 

所以，当我点击选择按钮，他需要改变的选择和刷新的UpdatePanel。所以：

public bool dane(int numerdysku) 
    { 

     string connectionString = "data source=localhost ;initial catalog=archiwizacjatvs;user id=root;password=wsti"; 
     MySqlConnection conn = new MySqlConnection(connectionString); 
     try 
     { 
      conn.Open(); 
      MySqlDataAdapter dadapter = new MySqlDataAdapter("select nazwa_dysku,folder,nazwa_pliku,czas_trwania,rozmiar,data_utworzenia,data_modyfikacji,sciezka from archiwum where nazwa_dysku='" + DropDownList2.SelectedValue.ToString() + "'", conn); 
      DataTable tablica = new DataTable(); 
      dadapter.Fill(tablica); 
      DataTableReader datatablereader = tablica.CreateDataReader(); 
      //DataRow row; 
      if (tablica.Rows.Count > 0) 
      { 
       /*for (int i = 0; i <= tablica.Rows.Count-1; i++) 
        { 
        row = tablica.Rows[i]; 
        TextBox2.Text = row[1].ToString() + " : " + row[2].ToString() + " : " + row[3].ToString() + " : " + row[4].ToString() + " : " + row[5].ToString(); 
        }*/ 
       GridView1.DataSource = tablica; 
       GridView1.DataBind(); 
       conn.Close(); 

      } 
      else 
      { 
       TextBox2.Text = "Tablica jest pusta!"; 
      } 
      conn.Close(); 

     } 
     catch (Exception ex) 
     { 
      TextBox2.Text = ex.ToString(); 
     } 
     return true; 
    } 

protected void Page_Load(object sender, EventArgs e) 
{ 
    string connectionString = "data source=localhost ;initial catalog=archiwizacjatvs;user id=user;password=password"; 
       MySqlConnection conn = new MySqlConnection(connectionString); 
       try 
       { 
        conn.Open(); 
        MySqlDataAdapter dadapter = new MySqlDataAdapter("select * from archiwum order by nazwa_dysku DESC", conn); 
        DataTable tablica = new DataTable(); 
        dadapter.Fill(tablica); 
        DataTableReader datatablereader = tablica.CreateDataReader(); 
        DataRow row = tablica.Rows[0]; 
        for (int i = 1; i <= Convert.ToInt64(row[1]); i++) 
        { 
        DropDownList2.Items.Add(i.ToString()); 
        } 
        conn.Close(); 
       } 
       catch (Exception ex) 
       { 
        TextBox2.Text = ex.ToString(); 
       } 
} 

protected void DropDownList2_SelectedIndexChanged(object sender, EventArgs e) 
    { 
     dane(DropDownList2.SelectedIndex); 
    } 

protected void GridView1_SelectedIndexChanging(object sender, GridViewSelectEventArgs e) 
    { 
     GridView1.SelectedIndex = e.NewSelectedIndex; 
     TextBox2.Text = GridView1.SelectedIndex.ToString(); 
    } 

    protected void GridView1_SelectedIndexChanged(object sender, EventArgs e) 
    { 
     dane(DropDownList2.SelectedIndex); 
    } 

它的工作与第一选择或从未...如果我按了几次F5它的工作再次。我应该改变什么？

Answer 1

为什么要设置EnableViewState="false"？当你点击按钮时，你的Gridview数据不会显示，因为page PostBack你的viewState没有被维护，因为你将它设置为false。但是当你按下F5键时，整个页面将刷新并获取数据。

只需从updatepanel中删除EnableViewState="false"，它就可以工作。

其次，把下面的条件在你的Page_Load !IsPostBack下：

protected void Page_Load(object sender, EventArgs e) 
{ 
if(!IsPostBack) 
{ 
string connectionString = "data source=localhost ;initial catalog=archiwizacjatvs;user id=user;password=password"; 
      MySqlConnection conn = new MySqlConnection(connectionString); 
      try 
      { 
       conn.Open(); 
       MySqlDataAdapter dadapter = new MySqlDataAdapter("select * from archiwum order by nazwa_dysku DESC", conn); 
       DataTable tablica = new DataTable(); 
       dadapter.Fill(tablica); 
       DataTableReader datatablereader = tablica.CreateDataReader(); 
       DataRow row = tablica.Rows[0]; 
       for (int i = 1; i <= Convert.ToInt64(row[1]); i++) 
       { 
       DropDownList2.Items.Add(i.ToString()); 
       } 
       conn.Close(); 
      } 
      catch (Exception ex) 
      { 
       TextBox2.Text = ex.ToString(); 
      } 

}