更新數據集時不更新ASP.NET中繼器

Question

我意識到這是一個愚蠢的問題，但仍然存在。

我有一個頁面，其中填充了數據的一個DataSet。 所有數據集綁定到Repeater。在該中繼器中，我有一個ImageButton，它有一個onCommand事件，負責從數據庫中刪除選擇的項目。 這的確是PostBack發生的？所以Page_PreRender被解僱了，還是我錯了？

我想實現的是，當發生回發發生變化時，我希望中繼器獲取最新信息。我檢查頁面的Load事件是否發生了變化，並在PreRendering開始之前獲取新數據，但在發生回發之後，屏幕上仍顯示相同的信息。

Page_Load事件發生在Page_PreRender事件之前，這意味着在收集新數據後，中繼器會被綁定，對嗎？

任何人都可以幫助或解釋我的邏輯錯誤的地方嗎？

這裏是Page_PreRender事件

/// <summary> 
/// Making sure that every repeater rebinds their datasets on every postback. 
/// If not, then the onCommand events of the buttons will break. 
/// </summary> 
/// <param name="sender">The page</param> 
/// <param name="e"></param> 
protected void Page_PreRender(object sender, EventArgs e) 
{ 
    if (Page.IsPostBack) //These repeaters are only visible after going to step 2 in the wizard 
         //(thus after at least one postback) 
    { 
     rptDeleteGroups.DataSource = dsGroupsPerFestival; 
     rptDeleteGroups.DataBind(); 

     rptDeleteCampSites.DataSource = dsCampSitesPerFestival; 
     rptDeleteCampSites.DataBind(); 

     rptDeleteTickets.DataSource = dsTicketsPerFestival; 
     rptDeleteTickets.DataBind(); 
    } 
    rptBandOverview.DataSource = dsGroupsPerFestival; 
    rptBandOverview.DataBind(); 

    rptCampSiteOverview.DataSource = dsCampSitesPerFestival; 
    rptCampSiteOverview.DataBind(); 

    rptTicketOverview.DataSource = dsTicketsPerFestival; 
    rptTicketOverview.DataBind(); 
} 

這是Page_OnLoad功能

protected void Page_Load(object sender, EventArgs e) 
{ 
    if (!Page.IsPostBack) 
    { 
     strFormIdFest = Request["hidden_fest_id"]; //Getting the submitted festival id 
     if (strFormIdFest == null) //if this string doesn't exist, then user was redirected from group details page 
     { 
      strFormIdFest = Session["fest_id"].ToString(); //Then get the id from the predefined session variable. 
      Session.Remove("fest_id"); //Remove this variable from the session 
     } 
     Session["festId"] = strFormIdFest; //Placing the festival id in a sessionVariable 

     overViewEditing.Visible = false; 
    } 
    else 
    { 
     strFormIdFest = Session["festId"].ToString(); 
    } 

    if (Session["EditsMade"] == null || (Boolean)Session["EditsMade"]) 
    { 
     Session["EditsMade"] = false; 
     getDataFromDatabase(); 
    } 
    else 
    { 
     getDataFromSession(); 
    } 
} 

的getDataFromDatabase和getDataFromSession功能：

/// <summary> 
/// Fills all the datasets required for this page to run properly with data from the database 
/// </summary> 
protected void getDataFromSession() 
{ 
    dsFestival = (DataSet)Session["Festival"]; 
    dsGroupsPerFestival = (DataSet)Session["GroupsPerFestival"]; 
    dsCampSitesPerFestival = (DataSet)Session["CampSitesPerFestival"]; 
    dsTicketsPerFestival = (DataSet)Session["TicketsPerFestival"]; 

    dsGroupsAll = (DataSet)Session["GroupsAll"]; 
    dsCamSitesAll = (DataSet)Session["CampSitesAll"]; 
    dsTicketsAll = (DataSet)Session["TicketsAll"]; 
    dsStagesAll = (DataSet)Session["StagesAll"]; 

    dsGroupsNotOnFestival = (DataSet)Session["GroupsNotOnFestival"]; 
    dsCampSitesNotOnFestival = (DataSet)Session["CampSitesNotOnFestival"]; 
    dsTicketsNotOnFestival = (DataSet)Session["TicketsNotOnFestival"]; 
} 

/// <summary> 
/// Fills all the datasets required for this page to run properly with data from the database 
/// </summary> 
protected void getDataFromDatabase() 
{ 
    //Collecting details about the chosen festival 
    dsFestival = webService.Festivals_GetFestival(strFormIdFest); 
    Session["Festival"] = dsFestival; 

    //Collecting all bands performing on the chosen festival 
    dsGroupsPerFestival = webService.Festivals_GetBandsOfFestival(strFormIdFest); 
    Session["GroupsPerFestival"] = dsGroupsPerFestival; 

    dsCampSitesPerFestival = webService.Festivals_GetCampingsOfFestival(strFormIdFest); 
    Session["CampSitesPerFestival"] = dsCampSitesPerFestival; 

    dsTicketsPerFestival = webService.Festivals_GetTicketTypesOfFestival(strFormIdFest); 
    Session["TicketsPerFestival"] = dsTicketsPerFestival; 

    //Filling all datasets with all available groups, tickets and campsites 
    dsGroupsAll = webService.Festivals_GetBandsNotOfFestival(strFormIdFest); 
    Session["GroupsAll"] = dsGroupsAll; 

    dsTicketsAll = webService.Festivals_GetTicketTypesNotOfFestival(strFormIdFest); 
    Session["TicketsAll"] = dsTicketsAll; 

    dsCamSitesAll = webService.Festivals_GetCampingsNotOfFestival(strFormIdFest); 
    Session["CampSitesAll"] = dsTicketsAll; 

    dsStagesAll = webService.Festivals_GetStages(); 
    Session["StagesAll"] = dsStagesAll; 

    //Filling dataset with groups, campsites and tickets not on this festival 
    dsGroupsNotOnFestival = webService.Festivals_GetBandsOfFestival("%"); 

    Session["GroupsNotOnFestival"] = dsGroupsNotOnFestival; 

    dsCampSitesNotOnFestival = webService.Festivals_GetCampingsNotOfFestival(strFormIdFest); 
    Session["CampSitesNotOnFestival"] = dsCampSitesNotOnFestival; 

    dsTicketsNotOnFestival = webService.Festivals_GetTicketTypesNotOfFestival(strFormIdFest); 
    Session["TicketsNotOnFestival"] = dsTicketsNotOnFestival; 
} 

這裏是與中繼行動處理器

<asp:Repeater ID="rptDeleteGroups" runat="server"> 
    <ItemTemplate> 
     <asp:UpdatePanel ID="DeleteGroupUpdatePanel" runat="server"> 
      <ContentTemplate> 
       <li> 
        <asp:Label ID="lblGroupName" runat="server" Text='<%# Eval("band_naam") %>' /></li> 
       <li style="border-bottom: 1px solid white;"> 
        <asp:Label ID="lblStageD" runat="server" Text='<%# Eval("pod_omschr") %>' /> 
        <asp:ImageButton ID="btnDeleteGroup" runat="server" ImageUrl="~/Images/minus.png" Width="20px" 
         OnCommand="btnDeleteGroup_Command" CommandName='<%# Eval("band_id") + "-" + Eval("pod_id") %>' meta:resourcekey="btnDeleteGroupResource1" /> 
       </li> 
      </ContentTemplate> 
     </asp:UpdatePanel> 
    </ItemTemplate> 
</asp:Repeater> 

/// <summary> 
/// Deletes a group based on the group id and stage id contained in the commandname 
/// </summary> 
/// <param name="sender"></param> 
/// <param name="e">Stats about the event, like the commandname</param> 
protected void btnDeleteGroup_Command(object sender, CommandEventArgs e) 
{ 
    String[] arguments = e.CommandName.Split(new char[] { '-' }, StringSplitOptions.None); 

    try 
    { 
     int intResult = webService.Festivals_DeleteBandFestival(strFormIdFest, arguments[0], arguments[1]); 

     divResult.Visible = true; 
     lblResult.ForeColor = System.Drawing.Color.White; 
     if (intResult == 1) 
     { 
      lblResult.Text = GetLocalResourceObject("SaveSuccess").ToString(); 
      Session["EditsMade"] = true; 
     } 
     else if (intResult == -1) 
     { 
      lblResult.ForeColor = System.Drawing.Color.LightSalmon; 
      lblResult.Text = GetLocalResourceObject("ErrorNoDeleted").ToString(); 
     } 
     else if (intResult > 1) 
     { 
      lblResult.Text = GetLocalResourceObject("ErrorMultipleDeleted").ToString(); 
      Session["EditsMade"] = true; 
     } 
    } 
    catch (Exception fatal) 
    { 
     divResult.Visible = true; 
     lblResult.ForeColor = System.Drawing.Color.LightSalmon; 
     lblResult.Text = GetLocalResourceObject("Error").ToString(); 
    } 
} 

Answer 1

海事組織，你應該這樣編寫你的中繼的ItemCommand事件：

if(e.CommandArgument=="Delete") 
{ 
    try 
    { 
    // Delete Logic 
    // Binding repeaters again 
    } 
    catch 
    { 
    // exception handling code 
    } 
}