Question

I am trying to make something like this:

Master detail gridview

But give me error in this line from cs file when i click Show details in the GridView:

gvRow.FindControl("GridView2").Visible = true;

I am trying when i click Show details to see the Names from other table where ID_Proba is = to ID from first Table.

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" 
    DataKeyNames="id" DataSourceID="SqlDataSource1" 
    onselectedindexchanged="GridView1_SelectedIndexChanged">
    <Columns>
        <asp:BoundField 
        DataField="id" 
        HeaderText="id" 
        ReadOnly="True" 
        SortExpression="id" InsertVisible="False" />
        <asp:BoundField 
        DataField="name" 
        HeaderText="name" 
        SortExpression="name" />
        <asp:CommandField ShowSelectButton="True" 
              SelectText="Show Details"/>
    </Columns>
    <EmptyDataTemplate>
        <asp:GridView ID="GridView2" runat="server" AutoGenerateColumns="False" 
            DataKeyNames="id" DataSourceID="SqlDataSource2" Visible="False">
            <Columns>
                <asp:BoundField DataField="id" 
                                HeaderText="id" 
                                SortExpression="id" InsertVisible="False" ReadOnly="True" />
                <asp:BoundField DataField="id_proba" 
                                HeaderText="id_proba" 
                                SortExpression="id_proba" />
                <asp:BoundField DataField="name" 
                                HeaderText="name" 
                                SortExpression="name" />
            </Columns>
        </asp:GridView>
    </EmptyDataTemplate>
</asp:GridView>
<asp:SqlDataSource ID="SqlDataSource1" runat="server" 
    ConnectionString="<%$ ConnectionStrings:ProbaConnectionString %>" 
    SelectCommand="SELECT * FROM [Proba1]"></asp:SqlDataSource>
<asp:SqlDataSource ID="SqlDataSource2" runat="server" 
    ConnectionString="<%$ ConnectionStrings:ProbaConnectionString %>" 
    SelectCommand="SELECT * FROM [proba3] WHERE ([id_proba] = @id_proba)">
    <SelectParameters>
        <asp:Parameter Name="id_proba" Type="Int32" />
    </SelectParameters>
</asp:SqlDataSource>
</form>

This is the cs file:

protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
{
    foreach (GridViewRow gvRow in GridView1.Rows)
    {
        gvRow.FindControl("GridView2").Visible = true;
    }
    SqlDataSource2.SelectParameters[0].DefaultValue = GridView1.SelectedDataKey[0].ToString();
    GridView1.SelectedRow.FindControl("GridView2").Visible = true;    
}

Answer 1

You need to take “GridView2” out of the EmptyDataTemplate and put it in a TemplateField. When you have data, the EmptyDataTemplate is not created at all, and also there is no grid in each row, because this template is for the whole grid.

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" 
    DataKeyNames="id" DataSourceID="SqlDataSource1" 
    onselectedindexchanged="GridView1_SelectedIndexChanged">
    <Columns>
        <asp:BoundField 
        DataField="id" 
        HeaderText="id" 
        ReadOnly="True" 
        SortExpression="id" InsertVisible="False" />
        <asp:BoundField 
        DataField="name" 
        HeaderText="name" 
        SortExpression="name" />
        <asp:CommandField ShowSelectButton="True" 
              SelectText="Show Details"/>
<asp:TemplateField>
    <ItemTemplate>
        <asp:GridView ID="GridView2" runat="server" AutoGenerateColumns="False" 
            DataKeyNames="id" DataSourceID="SqlDataSource2" Visible="False">
            <Columns>
                <asp:BoundField DataField="id" 
                                HeaderText="id" 
                                SortExpression="id" InsertVisible="False" ReadOnly="True" />
                <asp:BoundField DataField="id_proba" 
                                HeaderText="id_proba" 
                                SortExpression="id_proba" />
                <asp:BoundField DataField="name" 
                                HeaderText="name" 
                                SortExpression="name" />
            </Columns>
        </asp:GridView>
    </ItemTemplate>
<asp:TemplateField>
</Columns>
</asp:GridView>
<asp:SqlDataSource ID="SqlDataSource1" runat="server" 
    ConnectionString="<%$ ConnectionStrings:ProbaConnectionString %>" 
    SelectCommand="SELECT * FROM [Proba1]"></asp:SqlDataSource>
<asp:SqlDataSource ID="SqlDataSource2" runat="server" 
    ConnectionString="<%$ ConnectionStrings:ProbaConnectionString %>" 
    SelectCommand="SELECT * FROM [proba3] WHERE ([id_proba] = @id_proba)">
    <SelectParameters>
        <asp:Parameter Name="id_proba" Type="Int32" />
    </SelectParameters>
</asp:SqlDataSource>
</form>