Clear and add row to ASP.Net GridView using C# and VB.Net

Hi JonJacobs,

Please refere below sample.

Note: For this sample i have used temporary DataTable. For more details refer How to create Temporary Table in ASP.Net using C# and VB.Net.

HTML

<asp:GridView runat="server" ID="gvCustomers" AutoGenerateColumns="false">
    <Columns>
        <asp:BoundField DataField="Name" HeaderText="Name" />
        <asp:BoundField DataField="Country" HeaderText="Country" />
    </Columns>
</asp:GridView>
<hr />
<table>
    <tr>
        <th>Name:</th>
        <th>Country:</th>
    </tr>
    <tr>
        <td><asp:TextBox ID="txtName" runat="server" /></td>
        <td><asp:TextBox ID="txtCountry" runat="server" /></td>
    </tr>
    <tr>
        <td colspan="2" style="text-align: center">
            <asp:Button Text="Insert Data" OnClick="Insert" runat="server" /></td>
    </tr>
</table>

Namespaces

C#

using System.Data;

VB.Net

Imports System.Data

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        DataTable dt = GetData();
        this.gvCustomers.DataSource = dt;
        this.gvCustomers.DataBind();
    }
}

private DataTable GetData()
{
    DataTable dt = new DataTable();
    dt.Columns.AddRange(new DataColumn[] {
                        new DataColumn("Name"),
                        new DataColumn("Country")
    });

    dt.Rows.Add("John Hammond", "United States");
    dt.Rows.Add("Mudassar Khan", "India");
    dt.Rows.Add("Suzanne Mathews", "France");
    dt.Rows.Add("Robert Schidner", "Russia");

    return dt;
}

//Clear GridView data and Inser new data.
protected void Insert(object sender, EventArgs e)
{
    this.gvCustomers.DataSource = null;
    DataTable dt = GetData();
    dt.Clear();
    dt.Rows.Add(this.txtName.Text,this.txtCountry.Text);
    this.gvCustomers.DataSource = dt;
    this.gvCustomers.DataBind();
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Dim dt As DataTable = GetData()
        Me.gvCustomers.DataSource = dt
        Me.gvCustomers.DataBind()
    End If
End Sub

Private Function GetData() As DataTable
    Dim dt As DataTable = New DataTable()
    dt.Columns.AddRange(New DataColumn() {New DataColumn("Name"), New DataColumn("Country")})
    dt.Rows.Add("John Hammond", "United States")
    dt.Rows.Add("Mudassar Khan", "India")
    dt.Rows.Add("Suzanne Mathews", "France")
    dt.Rows.Add("Robert Schidner", "Russia")
    Return dt
End Function

Protected Sub Insert(ByVal sender As Object, ByVal e As EventArgs)
    Me.gvCustomers.DataSource = Nothing
    Dim dt As DataTable = GetData()
    dt.Clear()
    dt.Rows.Add(Me.txtName.Text, Me.txtCountry.Text)
    Me.gvCustomers.DataSource = dt
    Me.gvCustomers.DataBind()
End Sub

Screenshot