c# - 如何在不刷新整个页面的情况下获得刷新的表格？

Question

我正在开发一个 ASP.NET Intranet Web 应用程序，它是一个测验引擎。由于我是一名新的 ASP.NET 开发人员，因此我有一个表格显示从用户收到的一些反馈，并且管理员可以使用 DropDownList 接受或拒绝这些反馈。

在此表下，有一个 JQuery Accordion，当管理员单击它时，他将看到一个表，其中包含过去三个月收到的反馈。但是，当管理员接受或拒绝其中一项反馈，然后单击“ Accordion ”时，他将看到该表格，但没有该反馈，即使该反馈是上个月提交的反馈之一。但是，当您刷新页面然后单击 Accordion 时，他就会看到它。

那么有什么功能可以帮助我通过刷新整个页面来获得自动刷新表格吗？ 有什么帮助吗？

ASP.NET 代码:

<asp:GridView ID="GridView1" runat="server" AllowPaging="True" 
                        AllowSorting="True" AutoGenerateColumns="False" DataKeyNames="ID" 
                        width="950px" CssClass="mGrid"
                        AlternatingRowStyle-CssClass="alt" 
                        RowStyle-HorizontalAlign="Center" 
                        DataSourceID="SqlDataSource1" 
                        OnRowDataBound="GridView1_RowDataBound" >
            <AlternatingRowStyle BackColor="White" ForeColor="#284775" />
            <HeaderStyle Font-Bold = "true" ForeColor="Black" Height="20px"/> 
            <Columns>
                <asp:BoundField DataField="ID" HeaderText="ID" InsertVisible="False" 
                    ReadOnly="True" SortExpression="ID" />
                <asp:BoundField DataField="Title" HeaderText="Title" SortExpression="Title" />
                <asp:BoundField DataField="Description" HeaderText="Description" 
                    SortExpression="Description" />
                <asp:BoundField DataField="Name" HeaderText="Name" SortExpression="Name" />
                <asp:BoundField DataField="Username" HeaderText="Username" 
                    SortExpression="Username" />
                <asp:BoundField DataField="DivisionShortcut" HeaderText="Division" 
                    SortExpression="DivisionShortcut" />
                <asp:TemplateField HeaderText="Status">
                    <ItemTemplate>
                        <asp:DropDownList ID="DropDownList" runat="server" DataSourceID="SqlDataSource2"
                                          Font-Bold="True" ForeColor="#006666" AppendDataBoundItems="false" 
                                          DataTextField="Status" DataValueField="ID" AutoPostBack="true" 
                                          OnDataBound="DropDownList_DataBound" OnSelectedIndexChanged ="DropDownList_SelectedIndexChanged">
                        </asp:DropDownList>
                    </ItemTemplate>
                </asp:TemplateField>
            </Columns>
        </asp:GridView>
        <asp:SqlDataSource ID="SqlDataSource1" runat="server" 
            ConnectionString="<%$ ConnectionStrings:testConnectionString %>" 
            SelectCommand="SELECT     dbo.SafetySuggestionsLog.ID, dbo.SafetySuggestionsLog.Title, dbo.SafetySuggestionsLog.Description, dbo.employee.Name, dbo.SafetySuggestionsLog.Username, 
                      dbo.Divisions.DivisionShortcut
FROM         dbo.employee INNER JOIN
                      dbo.SafetySuggestionsLog ON dbo.employee.Username = dbo.SafetySuggestionsLog.Username INNER JOIN
                      dbo.Divisions ON dbo.employee.DivisionCode = dbo.Divisions.SapCode"
                      FilterExpression="[DivisionShortcut] like '{0}%'">

                      <FilterParameters>
                        <asp:ControlParameter ControlID="ddlDivision" Name="DivisionShortcut" 
                                                 PropertyName="SelectedValue" Type="String" />
                    </FilterParameters>
        </asp:SqlDataSource>

        <%--For the DropDownList--%>
        <asp:SqlDataSource ID="SqlDataSource2" runat="server"
                            ConnectionString="<%$ ConnectionStrings:testConnectionString %>" 
                            SelectCommand="SELECT * FROM [SafetySuggestionsStatus]">
        </asp:SqlDataSource>

        <%--Filtering by Division--%>
        <asp:SqlDataSource ID="sqlDataSourceDivision" runat="server" 
        ConnectionString="<%$ ConnectionStrings:testConnectionString %>" 
        SelectCommand="SELECT [DivisionShortcut] FROM [Divisions]"></asp:SqlDataSource>

<dl id="jfaq">
            <br />
                <dt>Safety Suggestions List (for the last three months)</dt>
                    <dd> 
                        <br />
                        <asp:Panel ID="Panel1" runat="server">
                        <asp:GridView ID="GridView2" runat="server" AutoGenerateColumns="False" 
                                      AllowSorting="True" CssClass="mGrid"
                                      AlternatingRowStyle-CssClass="alt" 
                                      RowStyle-HorizontalAlign="Center" 
                                      DataSourceID="SqlDataSource4">
                            <AlternatingRowStyle BackColor="White" ForeColor="#284775" />
                            <HeaderStyle Font-Bold = "true" ForeColor="Black" Height="20px"/> 
                            <Columns>
                                <asp:BoundField DataField="SubmittedMonth" HeaderText="Submitted Month" 
                                    SortExpression="SubmittedMonth" ReadOnly="True" />
                                <asp:BoundField DataField="DivisionShortcut" HeaderText="Division" 
                                    SortExpression="DivisionShortcut" />
                                <asp:BoundField DataField="Username" HeaderText="Username" 
                                    SortExpression="Username" />
                                <asp:BoundField DataField="Name" HeaderText="Name" 
                                    SortExpression="Name" />
                                <asp:BoundField DataField="Title" HeaderText="Title" SortExpression="Title" />
                                <asp:BoundField DataField="Description" HeaderText="Description" 
                                    SortExpression="Description" />
                                <asp:BoundField DataField="Type" HeaderText="Type" SortExpression="Type" />
                                <asp:BoundField DataField="Status" HeaderText="Status" 
                                    SortExpression="Status" />
                            </Columns>
                                <RowStyle HorizontalAlign="Center"></RowStyle>
                        </asp:GridView>
                        </asp:Panel>
                        <asp:SqlDataSource ID="SqlDataSource4" runat="server" 
                            ConnectionString="<%$ ConnectionStrings:testConnectionString %>" SelectCommand="SELECT     TOP (100) PERCENT LEFT(DATENAME(month, dbo.SafetySuggestionsLog.DateSubmitted), 3) + '-' + DATENAME(year, dbo.SafetySuggestionsLog.DateSubmitted) 
                      AS SubmittedMonth, dbo.Divisions.DivisionShortcut, dbo.SafetySuggestionsLog.Username, dbo.employee.Name, dbo.SafetySuggestionsLog.Title, 
                      dbo.SafetySuggestionsLog.Description, dbo.SafetySuggestionsType.Type, dbo.SafetySuggestionsStatus.Status
FROM         dbo.Divisions INNER JOIN
                      dbo.employee ON dbo.Divisions.SapCode = dbo.employee.DivisionCode INNER JOIN
                      dbo.SafetySuggestionsLog ON dbo.employee.Username = dbo.SafetySuggestionsLog.Username INNER JOIN
                      dbo.SafetySuggestionsType ON dbo.SafetySuggestionsLog.TypeID = dbo.SafetySuggestionsType.ID INNER JOIN
                      dbo.SafetySuggestionsStatus ON dbo.SafetySuggestionsLog.StatusID = dbo.SafetySuggestionsStatus.ID
WHERE     (DATEDIFF(month, dbo.SafetySuggestionsLog.DateSubmitted, GETDATE()) &lt; 3)
ORDER BY dbo.SafetySuggestionsLog.DateSubmitted DESC">
                       </asp:SqlDataSource>

                       <asp:Button ID="btnPrint" runat="server" Text="Print" OnClick="btnPrint_Click" />
                       </dd>
                 </dl>

隐藏代码:

protected void DropDownList_SelectedIndexChanged(object sender, EventArgs e)
    {
        DropDownList ddl = (DropDownList)sender;
        int suggestionStatus = int.Parse(ddl.SelectedValue);
        GridViewRow row = (GridViewRow)ddl.NamingContainer;
        string strID = GridView1.DataKeys[row.RowIndex]["ID"].ToString();
        int ID = Int32.Parse(strID);
        //For inserting the status in the database
        string connString = "Data Source=localhost\\sqlexpress;Initial Catalog=psspdbTest;Integrated Security=True";
        string updateCommand = "UPDATE SafetySuggestionsLog  SET [StatusID] = @StatusID WHERE [ID] = @ID";
        using (SqlConnection conn = new SqlConnection(connString))
        {
            conn.Open();
            using (SqlCommand cmd = new SqlCommand(updateCommand, conn))
            {
                cmd.Parameters.Clear();
                cmd.Parameters.AddWithValue("@StatusID", suggestionStatus);
                cmd.Parameters.AddWithValue("@ID", ID);
                cmd.ExecuteNonQuery();
            }
            conn.Close();
        }

    }

更新: 我使用UpdatePanel控件来获取部分更新，我使用了<triggers> ，但我收到以下错误，我不知道为什么:

Could not find an event named 'Click' on associated control 'GridView2' for the trigger in UpdatePanel 'UpdatePanel1'.

<asp:UpdatePanel ID="UpdatePanel1" runat="server"> 
    <Triggers>
        <asp:AsyncPostBackTrigger ControlID="GridView2" EventName="Click" />
    </Triggers>
    <ContentTemplate>
       <dl id="jfaq">
            <br />
                <dt>Safety Suggestions List (for the last three months)</dt>
                    <dd> 
                        <br />
                        <asp:Panel ID="Panel1" runat="server">
                        <asp:GridView ID="GridView2" runat="server" AutoGenerateColumns="False" 
                                      AllowSorting="True" CssClass="mGrid"
                                      AlternatingRowStyle-CssClass="alt" 
                                      RowStyle-HorizontalAlign="Center" 
                                      DataSourceID="SqlDataSource4">
                            <AlternatingRowStyle BackColor="White" ForeColor="#284775" />
                            <HeaderStyle Font-Bold = "true" ForeColor="Black" Height="20px"/> 
                            <Columns>
                                <asp:BoundField DataField="SubmittedMonth" HeaderText="Submitted Month" 
                                    SortExpression="SubmittedMonth" ReadOnly="True" />
                                <asp:BoundField DataField="DivisionShortcut" HeaderText="Division" 
                                    SortExpression="DivisionShortcut" />
                                <asp:BoundField DataField="Username" HeaderText="Username" 
                                    SortExpression="Username" />
                                <asp:BoundField DataField="Name" HeaderText="Name" 
                                    SortExpression="Name" />
                                <asp:BoundField DataField="Title" HeaderText="Title" SortExpression="Title" />
                                <asp:BoundField DataField="Description" HeaderText="Description" 
                                    SortExpression="Description" />
                                <asp:BoundField DataField="Type" HeaderText="Type" SortExpression="Type" />
                                <asp:BoundField DataField="Status" HeaderText="Status" 
                                    SortExpression="Status" />
                            </Columns>
                                <RowStyle HorizontalAlign="Center"></RowStyle>
                        </asp:GridView>
                        </asp:Panel>
                        <asp:SqlDataSource ID="SqlDataSource4" runat="server" 
                            ConnectionString="<%$ ConnectionStrings:testConnectionString %>" SelectCommand="SELECT     TOP (100) PERCENT LEFT(DATENAME(month, dbo.SafetySuggestionsLog.DateSubmitted), 3) + '-' + DATENAME(year, dbo.SafetySuggestionsLog.DateSubmitted) 
                      AS SubmittedMonth, dbo.Divisions.DivisionShortcut, dbo.SafetySuggestionsLog.Username, dbo.employee.Name, dbo.SafetySuggestionsLog.Title, 
                      dbo.SafetySuggestionsLog.Description, dbo.SafetySuggestionsType.Type, dbo.SafetySuggestionsStatus.Status
FROM         dbo.Divisions INNER JOIN
                      dbo.employee ON dbo.Divisions.SapCode = dbo.employee.DivisionCode INNER JOIN
                      dbo.SafetySuggestionsLog ON dbo.employee.Username = dbo.SafetySuggestionsLog.Username INNER JOIN
                      dbo.SafetySuggestionsType ON dbo.SafetySuggestionsLog.TypeID = dbo.SafetySuggestionsType.ID INNER JOIN
                      dbo.SafetySuggestionsStatus ON dbo.SafetySuggestionsLog.StatusID = dbo.SafetySuggestionsStatus.ID
WHERE     (DATEDIFF(month, dbo.SafetySuggestionsLog.DateSubmitted, GETDATE()) &lt; 3)
ORDER BY dbo.SafetySuggestionsLog.DateSubmitted DESC">
                       </asp:SqlDataSource>

                       <asp:Button ID="btnPrint" runat="server" Text="Print" OnClick="btnPrint_Click" />
                       </dd>
                 </dl>

       </ContentTemplate>
    </asp:UpdatePanel>

Answer 1

在触发器中您提到了 Click 事件，但在后面的代码中只有 DropDownList_SelectedIndexChanged 事件。

相反，您可以触发 DropDownList 的 SelectedIndexChanged 事件

    <asp:AsyncPostBackTrigger ControlID="DropDownList" EventName="SelectedIndexChanged" />

您只需要在后面的代码中触发一个有效的事件即可。

更新:由于SelectedIndexChanged会更新数据库，因此需要刷新DataGrid以填充更新的数据。

在 SelectedIndexChanged 方法的末尾添加此行代码:

    GridView2.DataBind();