PagerTemplate в gridview не работает должным образом

Question

Я не понимаю, почему это происходит.

У меня есть Gridview, внутри которого я реализовал пейджер . Он показывает мне правильные записи, которые поступают из базы данных.

Прежде всего, я взял логику реализации части пейджера gridview от here. И я реализовал то же самое, что и описал их.

Теперь сценарий, который я придумал, заключается в том, что, когда я изменяю выбор выпадающего списка, мое gridview получает обратную передачу, и вся сетка становится нарушенной. Я не знаю, почему это происходит.

Смотрите код, который я реализовал: -

<asp:GridView ID="grdCSRPageData" runat="server" Width="100%" border="1" Style="border: 1px solid #E5E5E5;" CellPadding="3" 
      AutoGenerateColumns="False" OnDataBound="grdCSRPageData_DataBound" AllowPaging="true" CssClass="hoverTable" EmptyDataText="No Records Found" 
      OnPageIndexChanging="grdCSRPageData_PageIndexChanging" DataKeyNames="Id" OnRowDeleting="grdCSRPageData_RowDeleting" 
      PageSize="4" ShowFooter="true" OnRowEditing="grdCSRPageData_RowEditing" OnRowUpdating="grdCSRPageData_RowUpdating" 
      OnRowCancelingEdit="grdCSRPageData_RowCancelingEdit"> 
      <AlternatingRowStyle CssClass="k-alt" BackColor="#f5f5f5" /> 
      <Columns> 
       <asp:TemplateField HeaderText="Select" HeaderStyle-Width="5%" HeaderStyle-CssClass="k-grid td"> 
        <ItemTemplate> 
         <asp:CheckBox ID="chkSelect" runat="server" AutoPostBack="false" /> 
        </ItemTemplate> 
       </asp:TemplateField> 
       <asp:BoundField DataField="page_title" HeaderText="Page Title" ItemStyle-Width="30" HeaderStyle-CssClass="k-grid td" /> 
       <asp:BoundField DataField="page_description" HeaderText="Page Description" ItemStyle-Width="30" HeaderStyle-CssClass="k-grid td" /> 
       <asp:BoundField DataField="meta_title" HeaderText="Meta Title" ItemStyle-Width="30" HeaderStyle-CssClass="k-grid td" /> 
       <asp:BoundField DataField="meta_keywords" HeaderText="Meta Keywords" ItemStyle-Width="30" HeaderStyle-CssClass="k-grid td" /> 
       <asp:BoundField DataField="meta_description" HeaderText="Meta Description" ItemStyle-Width="30" HeaderStyle-CssClass="k-grid td" /> 
       <asp:BoundField DataField="Active" HeaderText="Active" ItemStyle-Width="30" HeaderStyle-CssClass="k-grid td" /> 
       <asp:TemplateField HeaderText="Action" HeaderStyle-Width="15%" HeaderStyle-CssClass="k-grid td"> 
        <ItemTemplate> 
         <asp:ImageButton ID="btnDelete" AlternateText="Delete" ImageUrl="~/images/delete.png" runat="server" Width="15" Height="15" CommandName="Delete" CommandArgument='<%# Eval("Id") %>' CausesValidation="false" OnClientClick="return confirm('Are you sure you want to delete this record?')" /> 
        </ItemTemplate> 
       </asp:TemplateField> 
       <asp:CommandField ButtonType="Image" ItemStyle-Width="15" EditImageUrl="~/images/edit.png" ShowEditButton="True" ControlStyle-Width="15" ControlStyle-Height="15" CancelImageUrl="~/images/close.png" UpdateImageUrl="~/images/update.png"> 
        <ControlStyle Height="20px" Width="20px"></ControlStyle> 
       </asp:CommandField> 
      </Columns> 
      <pagerstyle /> 
     <pagerTemplate> 
      <table style="width:100%"> 
       <tr> 
        <td> 
         <asp:label id="MessageLabel" Text="Select a page:" runat="server"/> 
      <asp:dropdownlist id="PageDropDownList" AutoPostBack="true" OnSelectedIndexChanged="PageDropDownList_SelectedIndexChanged" 
       runat="server"/> 

         <td style="width:70%; text-align:right"> 
         <asp:label id="CurrentPageLabel" runat="server"/> 
      </td> 

        </td> 
       </tr> 
      </table> 
     </pagerTemplate> 
     </asp:GridView> 

код добавляется с PagerTemplate. Также смотрите мой код позади, как дали свое: - Cs код для PagerTemplate: -

protected void grdCSRPageData_DataBound(object sender, EventArgs e) 
    { 
     GridViewRow pagerRow = grdCSRPageData.BottomPagerRow; 
     DropDownList pageList = (DropDownList)pagerRow.Cells[0].FindControl("PageDropDownList"); 
     Label pageLabel = (Label)pagerRow.Cells[0].FindControl("CurrentPageLabel"); 
     if (pageList != null) 
     { 
      for (int i = 0; i < grdCSRPageData.PageCount; i++) 
      { 
       int pageNumber = i + 1; 
       ListItem item = new ListItem(pageNumber.ToString()); 
       if (i == grdCSRPageData.PageIndex) 
       { 
        item.Selected = true; 
       } 
       pageList.Items.Add(item); 
      } 
     } 
     if (pageLabel != null) 
     { 
      int currentPage = grdCSRPageData.PageIndex + 1; 
      pageLabel.Text = "Page " + currentPage.ToString() + 
       " of " + grdCSRPageData.PageCount.ToString(); 
     } 
} 

protected void PageDropDownList_SelectedIndexChanged(object sender, EventArgs e) 
    { 
     GridViewRow pagerRow = grdCSRPageData.BottomPagerRow; 
     DropDownList pagelist = (DropDownList)pagerRow.Cells[0].FindControl("PageDropDownList"); 
     grdCSRPageData.PageIndex = pagelist.SelectedIndex; 
    } 

Пожалуйста, помогите. Любая помощь будет заметна

Answer 1

попробуйте изменить AutoPostBack="true" к false вашему DropDownList и убедитесь, что для загрузки данных в Page_Load внутри

if (!IsPostBack){ 
    //bind gridview 
} 

обновления

попробуйте вставить свой DropDownList (с AutoPostBack="true") и вашим GridView внутри UpdatePanel с "UpdateMode=Conditional" следующим образом

<asp:UpdatePanel runat="server" ID="up1" UpdateMode="Conditional"> 
    <ContentTemplate> 
     //put here gridview 
    <ContentTemplate> 
    <Triggers> 
     <asp:AsyncPostBackTrigger ControlID="PageDropDownList" EventName="SelectedIndexChanged" /> 
    </Triggers> 
    </asp:UpdatePanel> 

обновление

попробовать это решение с кодом

ASPX страница

<asp:GridView ID="grdUser" 
    AllowPaging="true" 
    AutoGenerateColumns="False" 
    OnDataBound="grdUser_DataBound" 
    OnRowDeleting="grdUser_RowDeleting" 
    OnPreRender="PreRenderGrid" 
    runat="server" 
    Width="100%" 
    border="1" 
    DataKeyNames="Id" 
    PageSize="2" 
    OnPageIndexChanging="grdUser_PageIndexChanging" 
    EnableSortingAndPagingCallbacks="false" 
    CssClass="pagi" OnRowCommand="grdUser_RowCommand"> 
<Columns> 
<asp:TemplateField HeaderText="Select" ItemStyle-Width="30" HeaderStyle-CssClass="k-grid td"> 
<ItemTemplate> 
<asp:CheckBox ID="chkDelete" runat="server" /> 
</ItemTemplate> 

    <HeaderStyle CssClass="k-grid td"></HeaderStyle> 

    <ItemStyle Width="30px"></ItemStyle> 
    </asp:TemplateField> 

    <asp:BoundField DataField="username" HeaderText="UserName" ItemStyle-Width="30" HeaderStyle-CssClass="k-grid td"> 
    <HeaderStyle CssClass="k-grid td"></HeaderStyle> 

    <ItemStyle Width="30px"></ItemStyle> 
</asp:BoundField> 
<asp:BoundField DataField="email" HeaderText="Email Id" ItemStyle-Width="30" HeaderStyle-CssClass="k-grid td"> 
    <HeaderStyle CssClass="k-grid td"></HeaderStyle> 

     <ItemStyle Width="30px"></ItemStyle> 
</asp:BoundField> 
<asp:BoundField DataField="usertype" HeaderText="UserType" ItemStyle-Width="30" HeaderStyle-CssClass="k-grid td"> 
<HeaderStyle CssClass="k-grid td"></HeaderStyle> 

<ItemStyle Width="30px"></ItemStyle> 
</asp:BoundField> 
<asp:BoundField DataField="active" HeaderText="Active" ItemStyle-Width="30" HeaderStyle-CssClass="k-grid td"> 
    <HeaderStyle CssClass="k-grid td"></HeaderStyle> 

    <ItemStyle Width="30px"></ItemStyle> 
</asp:BoundField> 
    <asp:TemplateField HeaderText="Action" HeaderStyle-Width="5%" ItemStyle-Width="20" HeaderStyle-CssClass="k-grid td"> 
    <ItemTemplate> 
    <asp:ImageButton ID="btnDelete" AlternateText="Delete" ImageUrl="~/images/delete.png" runat="server" Width="15" Height="15" CommandName="eEdit" CommandArgument='<%# Eval("Id") %>' CausesValidation="false" OnClientClick="return confirm('Are you sure you want to delete this record?')" /> 
    </ItemTemplate> 
</asp:TemplateField> 
<asp:TemplateField> 
<ItemTemplate> 
    <asp:ImageButton ID="btnEdit" AlternateText="Edit" ImageUrl="~/images/edit.png" runat="server" Width="15" Height="15" CommandName="eEdit" CommandArgument='<%# Eval("Id") %>' CausesValidation="false" /> 
</ItemTemplate> 

<HeaderStyle CssClass="k-grid td" Width="15%"></HeaderStyle> 

<ItemStyle Width="30px"></ItemStyle> 

</asp:TemplateField> 
</Columns> 

    <PagerStyle ForeColor="#e3e3e3" 
         BackColor="#e3e3e3" CssClass="grid-pagi" /> 
    <PagerTemplate> 
    <table runat="server" id="testTable1" style="width: 100%" class="k-grid td"> 
          <tr> 
           <td class="col-md-7 pull-left"> 
            <asp:Label ID="MessageLabel" 
             Text="Select a page:" 
             runat="server" /> 
            <asp:LinkButton ID="FirstLB" runat="server" CommandName="Page" CommandArgument="First" ToolTip="First" CssClass="btn-pager btn-default"><<</asp:LinkButton> 
            <asp:LinkButton ID="PrevLB" runat="server" CommandName="Page" CommandArgument="Prev" ToolTip="Previous" CssClass="btn-pager btn-default"><</asp:LinkButton> 
            <asp:DropDownList runat="server" ID="PageDropDownList" AutoPostBack="true" EnableViewState="true" OnSelectedIndexChanged="PageDropDownList_SelectedIndexChanged" CssClass="selectpicker form-control-drp"></asp:DropDownList> 

            <asp:LinkButton ID="NextLB" runat="server" CommandName="Page" CommandArgument="Next" ToolTip="Next" CssClass="btn-pager btn-default">></asp:LinkButton> 
            <asp:LinkButton ID="LastLB" runat="server" CommandName="Page" CommandArgument="Last" ToolTip="Last" CssClass="btn-pager btn-default">>></asp:LinkButton> 
           </td> 

           <td class="col-md-3 pull-right"> 
            <asp:Label ID="PageSizeLabel" runat="server" Text="Select Page Size: "></asp:Label> 
            <asp:DropDownList ID="ddlPageSize" runat="server" OnSelectedIndexChanged="ddlPageSize_SelectedIndexChanged" AutoPostBack="true" CssClass="selectpicker form-control-drp"> 
             <%-- <asp:ListItem Value="0" Text="0" />--%> 
             <asp:ListItem Value="1" Text="1" /> 
             <asp:ListItem Value="2" Text="2" /> 
             <asp:ListItem Value="3" Text="3" /> 
            </asp:DropDownList> 
           </td> 
           <td class="col-md-2"> 
            <asp:Label ID="CurrentPageLabel" runat="server" /> 
           </td> 
          </tr> 
         </table> 
        </PagerTemplate> 
       </asp:GridView> 

коды за

protected void grdUser_DataBound(object sender, EventArgs e) 
     { 
      GridViewRow pagerRow = grdUser.BottomPagerRow; 
      DropDownList pageSizeList = (DropDownList)pagerRow.Cells[0].FindControl("ddlPageSize"); 
      if (Context.Session["PageSize"] != null) 
      { 
       pageSizeList.SelectedValue = Context.Session["PageSize"].ToString(); 
      } 
      DropDownList pageList = (DropDownList)pagerRow.Cells[0].FindControl("PageDropDownList"); 
      Label pageLabel = (Label)pagerRow.Cells[0].FindControl("CurrentPageLabel"); 

      if (pageList != null) 
      { 
       for (int i = 0; i < grdUser.PageCount; i++) 
       { 
        int pageNumber = i + 1; 
        ListItem item = new ListItem(pageNumber.ToString()); 
        if (i == grdUser.PageIndex) 
        { 
         item.Selected = true; 
        } 
        pageList.Items.Add(item); 
       } 
      } 

      if (pageLabel != null) 
      { 
       int currentPage = grdUser.PageIndex + 1; 
       pageLabel.Text = "View " + currentPage.ToString() + " of " + grdUser.PageCount.ToString(); 
      } 
     } 
protected void ddlPageSize_SelectedIndexChanged(object sender, EventArgs e) 
     { 
      GridViewRow pagerRow = grdUser.BottomPagerRow; 
      DropDownList pageSizeList = (DropDownList)pagerRow.Cells[0].FindControl("ddlPageSize"); 
      // 

      grdUser.PageSize = Convert.ToInt32(pageSizeList.SelectedValue); 
      Context.Session["PageSize"] = pageSizeList.SelectedValue; 
      BindGrid(); 
     } 
     protected void PageDropDownList_SelectedIndexChanged(object sender, EventArgs e) 
     { 
      GridViewRow pagerRow = grdUser.BottomPagerRow; 
      DropDownList pageList = (DropDownList)pagerRow.Cells[0].FindControl("PageDropDownList"); 
      grdUser.PageIndex = pageList.SelectedIndex; 
      BindGrid(); 
     } 

protected void PreRenderGrid(object sender, EventArgs e) 
     { 
      GridViewRow pagerRow = grdUser.BottomPagerRow; 
      DropDownList pageList = (DropDownList)pagerRow.Cells[0].FindControl("PageDropDownList");//error 
      Label pageLabel = (Label)pagerRow.Cells[0].FindControl("CurrentPageLabel"); 
      if (pageList != null) 
      { 
       for (int i = 0; i < grdUser.PageCount; i++) 
       { 
        int pageNumber = i + 1; 
        ListItem item = new ListItem(pageNumber.ToString()); 
        if (i == grdUser.PageIndex) 
        { 
         item.Selected = true; 
        } 
        pageList.Items.Add(item); 
       } 
      } 
      if (pageLabel != null) 
      { 
       int currentPage = grdUser.PageIndex + 1; 
       pageLabel.Text = "View " + currentPage.ToString() + " of " + grdUser.PageCount.ToString(); 
      } 
      this.grdUser.Controls[0].Controls[this.grdUser.Controls[0].Controls.Count - 1].Visible = true; 
      BindGrid(); 
     }