CODEWITHSUNDEEP
asp.netvb.net
niclake
niclake

Reputation: 134

Adding Dropdown List Item to ASP GridView

I want to be able to take a selected item from a dropdown list, hit a button, and have that item added to a GridView to be viewed by the user. Right now, when I hit the + button, the grid displays, but the cells are blank. Any suggestions?

ASP code:

<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>

Initial GridView bind:

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

Additional code behind:

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

Upvotes: 0

Views: 1179

Answers (2)

sjramsay
sjramsay

Reputation: 555

See if this will work for you. I am more c# however this looked like it worked:

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

Upvotes: 1

sjramsay
sjramsay

Reputation: 555

This should work for you now. Change your GridView to the following:

<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>

Upvotes: 1

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