Question

我希望能够从下拉列表中选择一个项目，点击一个按钮，并将该项目添加到GridView以供用户查看。现在，当我按下+按钮时，网格显示，但是单元格是空白的。有什么建议吗？

ASP代码：

<tr>
    <td valign="top" colspan="2">
        <b>Agents Visited</b><br />
        <asp:DropDownList SelectionMode="Multiple" runat="server" ID="agentsDropdown" Name="agentsDropdown" width="425"></asp:DropDownList>
    </td>
    <td valign="top">
        <br />
        <asp:Button id="agentButton" name="agentButton" runat="server" Text="+" OnClick="AddAgent" CssClass="buttonstyle" onmouseover="shade(this);" onmouseout="unshade(this);" />
    </td>
</tr>
<tr>
    <asp:GridView ID="agentGridView" Visible="False" AllowSorting="False" AllowPaging="False" Runat="server" AutoGenerateColumns="False" PageSize="20"  >
<Columns>
        <asp:TemplateField HeaderText="Agent">
            <ItemTemplate>
                <asp:Label ID="agentName" runat="server" Text=''></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderText="Value">
            <ItemTemplate>
                <asp:Label ID="agentValue" runat="server" Text=''></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:CommandField ShowDeleteButton="True" />
    </Columns>
</asp:GridView>
</tr>

初始GridView绑定：

Private Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
    If Not Page.IsPostBack
        agentGridView.DataSource = Nothing
        agentGridView.Databind()
    End If
End Sub

背后的附加代码：

Protected Sub AddAgent(sender As Object, e As EventArgs)
    If agentsDropdown.SelectedIndex > 0 Then
        Dim dt As New DataTable

        dt.Columns.Add("agentName")
        dt.Columns.Add("agentValue")

        Dim row1 As DataRow = dt.NewRow
        row1.Item("agentName") = agentsDropdown.SelectedItem.Text.ToString()
        row1.Item("agentValue") = agentsDropdown.SelectedValue.ToString()
        dt.Rows.Add(row1)

        agentGridView.DataSource = dt
        agentGridView.DataBind()

        agentsDropdown.SelectedIndex = 0

        Dim agentRowsCount as Integer = agentGridView.Rows.Count
        If agentRowsCount > 0
            agentGridView.Visible = True
        End If
    End If
End Sub

Answer 1

这应该适合你。将GridView更改为以下内容：

<asp:GridView ID="agentGridView" Visible="False" AllowSorting="False" AllowPaging="False" Runat="server" AutoGenerateColumns="False" PageSize="20" >
<Columns>
        <asp:BoundField DataField="agentName" HeaderText="Agent Name" ItemStyle-Width="30" />
        <asp:BoundField DataField="agentValue" HeaderText="Agent Value" ItemStyle-Width="30" />
        <asp:CommandField ShowDeleteButton="True" />
   </Columns>
</asp:GridView>

Answer 2

看看这是否适合你。我更喜欢它＃然而这看起来很有效：

Public Class WebForm1
Inherits System.Web.UI.Page

Dim dt = Nothing

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

    If (Session("Agents") Is Nothing) Then
        dt = New DataTable
    Else
        dt = Session("Agents")
    End If
    If Not Page.IsPostBack Then
        agentGridView.DataSource = Nothing
        agentGridView.DataBind()
    End If

End Sub

Protected Sub AddAgent(sender As Object, e As EventArgs) Handles agentsDropdown.SelectedIndexChanged
    If agentsDropdown.SelectedIndex > 0 Then

        If (Session("Agents") Is Nothing) Then
            dt = New DataTable()
            dt.Columns.Add("agentName")
            dt.Columns.Add("agentValue")
        End If

        Dim row1 As DataRow = dt.NewRow
        row1.Item("agentName") = agentsDropdown.SelectedItem.Text.ToString()
        row1.Item("agentValue") = agentsDropdown.SelectedValue.ToString()
        dt.Rows.Add(row1)

        Session("Agents") = dt
        agentGridView.DataSource = dt
        agentGridView.DataBind()

        agentsDropdown.SelectedIndex = 0

        Dim agentRowsCount As Integer = agentGridView.Rows.Count
        If agentRowsCount > 0 Then
            agentGridView.Visible = True
        End If
    End If

End Sub

End Class

将下拉列表项添加到ASP GridView

2 个答案: