Calculate Average of Repeater column using C# and VB.Net in ASP.net

Hi Tevin,

Check this example. Now please take its reference and correct your code.

HTML

<table class="table table-striped table-bordered table-hover table-condensed" border="1">
    <tr>
        <td style="padding-bottom: 10px">Part Weight:<br />
            <asp:TextBox ID="txtPartWeight" runat="server" />
        </td>
        <td style="padding-bottom: 10px">Sprue Weight:<br />
            <asp:TextBox ID="txtSprueWeight" runat="server" />
        </td>
    </tr>
    <tr>
        <td colspan="2" align="center" style="width: 100px">
            <asp:Button ID="btnAdd" runat="server" Text="Add" OnClick="btnAdd_Click" />
        </td>
    </tr>
</table>
<asp:Repeater ID="rpAddedWights" runat="server">
    <HeaderTemplate>
        <table class="table table-striped table-bordered table-hover table-condensed" border="1">
            <thead>
                <tr>
                    <th>Part Weight (g)</th>
                    <th>Sprue Weight (g)</th>
                </tr>
            </thead>
            <tbody>
    </HeaderTemplate>
    <ItemTemplate>
        <tr runat="server">
            <td>
                <asp:Label Text='<%#DataBinder.Eval(Container.DataItem, "PartWeight")%>' runat="server" ID="lblPartWeight" /></td>
            <td>
                <asp:Label Text='<%#DataBinder.Eval(Container.DataItem, "SprueWeight")%>' runat="server" ID="lblSprueWeight" /></td>
        </tr>
    </ItemTemplate>
    <FooterTemplate>
        </tbody>
        <tfoot>
            <tr>
                <td>
                    <asp:Label ID="lblFPartWeight" runat="server"></asp:Label></td>
                <td>
                    <asp:Label ID="lblFSprueWeight" runat="server"></asp:Label></td>
            </tr>
        </tfoot>
        </table>
    </FooterTemplate>
</asp:Repeater>

Namespaces

C#

using System.Data;
using System.Linq;

VB.Net

Imports System.Data
Imports System.Linq

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        DataTable dt = new DataTable();
        dt.Columns.AddRange(new DataColumn[2] {
    new DataColumn("PartWeight"), new DataColumn("SprueWeight") });
        ViewState["Weights"] = dt;
        this.BindRepeater();
    }
}

protected void BindRepeater()
{
    DataTable dt = (DataTable)ViewState["Weights"];
    if (dt.Rows.Count > 0)
    {
        rpAddedWights.DataSource = dt;
        rpAddedWights.DataBind();
        var partWeight = dt.AsEnumerable().Select(x => Convert.ToDecimal(x["PartWeight"])).ToList().AsQueryable();
        var sprueWeight = dt.AsEnumerable().Select(x => Convert.ToDecimal(x["SprueWeight"])).ToList().AsQueryable();
        decimal averagePart = Queryable.Average(partWeight);
        decimal averageSprue = Queryable.Average(sprueWeight);
        (rpAddedWights.Controls[rpAddedWights.Controls.Count - 1].Controls[0].FindControl("lblFPartWeight") as Label).Text = "Average : <br/>" + Math.Round(averagePart, 2).ToString();
        (rpAddedWights.Controls[rpAddedWights.Controls.Count - 1].Controls[0].FindControl("lblFSprueWeight") as Label).Text = "Average : <br/>" + Math.Round(averageSprue, 2).ToString();
    }
}

protected void btnAdd_Click(object sender, EventArgs e)
{
    DataTable dt = (DataTable)ViewState["Weights"];
    if (dt.Rows.Count < 5)
    {
        dt.Rows.Add(txtPartWeight.Text.Trim(), txtSprueWeight.Text.Trim());
        ViewState["Customers"] = dt;
        this.BindRepeater();
    }
    else
    {
        ClientScript.RegisterClientScriptBlock(this.GetType(), "", "alert('You have reached the limit of rows added.')", true);
    }
    txtPartWeight.Text = string.Empty;
    txtSprueWeight.Text = string.Empty;
}

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 = New DataTable()
        dt.Columns.AddRange(New DataColumn(1) {New DataColumn("PartWeight"), New DataColumn("SprueWeight")})
        ViewState("Weights") = dt
        Me.BindRepeater()
    End If
End Sub

Protected Sub BindRepeater()
    Dim dt As DataTable = CType(ViewState("Weights"), DataTable)
    If dt.Rows.Count > 0 Then
        rpAddedWights.DataSource = dt
        rpAddedWights.DataBind()
        Dim partWeight = dt.AsEnumerable().Select(Function(x) Convert.ToDecimal(x("PartWeight"))).ToList().AsQueryable()
        Dim sprueWeight = dt.AsEnumerable().Select(Function(x) Convert.ToDecimal(x("SprueWeight"))).ToList().AsQueryable()
        Dim averagePart As Decimal = Queryable.Average(partWeight)
        Dim averageSprue As Decimal = Queryable.Average(sprueWeight)
        TryCast(rpAddedWights.Controls(rpAddedWights.Controls.Count - 1).Controls(0).FindControl("lblFPartWeight"), Label).Text = "Average : <br/>" & Math.Round(averagePart, 2).ToString()
        TryCast(rpAddedWights.Controls(rpAddedWights.Controls.Count - 1).Controls(0).FindControl("lblFSprueWeight"), Label).Text = "Average : <br/>" & Math.Round(averageSprue, 2).ToString()
    End If
End Sub

Protected Sub btnAdd_Click(ByVal sender As Object, ByVal e As EventArgs)
    Dim dt As DataTable = CType(ViewState("Weights"), DataTable)
    If dt.Rows.Count < 5 Then
        dt.Rows.Add(txtPartWeight.Text.Trim(), txtSprueWeight.Text.Trim())
        ViewState("Customers") = dt
        Me.BindRepeater()
    Else
        ClientScript.RegisterClientScriptBlock(Me.GetType(), "", "alert('You have reached the limit of rows added.')", True)
    End If

    txtPartWeight.Text = String.Empty
    txtSprueWeight.Text = String.Empty
End Sub

Screenshot