ASP.NET Repeater - Summary totals

wb2you

0/5 (0 vote)

Dec 18, 2012

CPOL

1 min read

29246

Generic approach to adding summary totals to an ASP.NET Repeater control.

Introduction

This is my first article, hope I'm doing it correct, I don't want to bore you with too much talk, so it's pretty much code, hope it suffices. I wanted a simple and& sort of generic approach to add summary totals to the footer record of a data repeater.

Background

My need was for a datatable that gets bound to a Repeater, plain and simple, with a summary total for the amount and count columns for every report I had to do. The table is a report coming straight from SQL Server via my backend.

Using the code

I have added all the code into this one file, so you can just copy it into any ASP.NET project and just run it.

First we need a private variable to hold the summary totals for the fields in the table that need to be summarized.

#region - Private variables -
// This will be a list of all the fields that needs to be totalled - Dictionary<fieldName, totalValue>
private Dictionary<string, decimal> totals = new Dictionary<string, decimal>();
#endregion

The next bit of code is purely to add sample data into the datatable. The data for the actual report will obviously come from your data source.

#region - This code belong in your backend -
// In my framework this method is a static in a DbHelper class
private void addDataColumn(DataTable table, string colName, string colType, bool colNull, object colDefault)
{
    DataColumn column = new DataColumn();
    column.DataType = System.Type.GetType(colType);
    column.ColumnName = colName;
    column.AllowDBNull = colNull;
    column.DefaultValue = colDefault;
    table.Columns.Add(column);
}
// Here we create the sample data for this report
private DataTable createDataTable()
{
    // This is your variable that will hold the report data
    DataTable dtData = new DataTable();
    addDataColumn(dtData, "RecordId", "System.Int32", false, 0);
    addDataColumn(dtData, "Description", "System.String", false, 0);
    addDataColumn(dtData, "TotalCount", "System.Int32", false, 0);
    addDataColumn(dtData, "TotalAmount", "System.Decimal", false, 0);
    // Fill Table with data
    for (int i = 1; i < 6; ++i)
    {
        DataRow dr = dtData.NewRow();
        dr["RecordId"] = i;
        dr["Description"] = "Description for row " + i;
        dr["TotalCount"] = i;
        dr["TotalAmount"] = i * 3.34m;
        dtData.Rows.Add(dr);
    }
    dtData.AcceptChanges();
    return dtData;
}
#endregion

The next method is the generic part that loops the table and summarize the fields that you've added in a dictionary. Again, I've added this method to a static helper class because you can then re-use it.

// I have this method in a static helper class
private void sumDataTable(DataTable dt, Dictionary<string, decimal> totals)
{
    List<string> keyList = new List<string>(totals.Keys);
    for (int i = 0; i < dt.Rows.Count; ++i)
    {
        foreach (string key in keyList)
        {
            totals[key] += Convert.ToDecimal(dt.Rows[i][key]);
        }
    }
}

Now we have the source code specifically to the report form, starting with the page load.
```
protected void Page_Load(object sender, EventArgs e)
{
    bindTableToForm();
} 
```
and then in my bind region, we have:

Create and get the sample data.
Add the columns that needs to be totaled into the Dictionary<fieldName, startvalue>.

Bind your data.

#region - Bind Methods -
private void bindTableToForm()
{
    // This is your variable that will hold the report data
    DataTable dtReport = createDataTable();
    // Do Total columns
    totals.Add("TotalCount", 0);
    totals.Add("TotalAmount", 0);
    sumDataTable(dtReport, totals);
    // 
    rprData.DataSource = dtReport;
    rprData.DataBind();
}
#endregion

We need to add a protected / public method to the page for the Repeater to access the summary totals in the dictionary.

#region - Public methods - 
protected string getTotalFor(string field, string formatString)
{
    decimal value = 0;
    totals.TryGetValue(field, out value);            
    return value.ToString(formatString);
}
#endregion

And finally the ASP.NET HTML code:

<%@ Page Language="C#" AutoEventWireup="true" 
  CodeBehind="RepeaterSummaryTotal.aspx.cs" Inherits="IQ.Web.RepeaterSummaryTotal" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
  "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <div id="reportResults">
            <br />
            <asp:Repeater ID="rprData" runat="server">
                <HeaderTemplate>
                    <table id="tblData"">
                        <thead>
                            <tr>
                                <th colspan="4">
                                    Report sample
                                </th>
                            </tr>
                            <tr>
                                <td>
                                    Id.
                                </td>
                                <td>
                                    Description
                                </td>
                                <td style="text-align:right">
                                    Total count
                                </td>
                                <td style="text-align:right">
                                    Total amount
                                </td>
                            </tr>
                        </thead>
                </HeaderTemplate>
                <ItemTemplate>
                    <tr class="even">
                        <td>
                            <%# Eval("RecordId")%>
                        </td>
                        <td>
                            <%# Eval("Description")%>
                        </td>
                        <td style="text-align:right">
                            <%# Eval("TotalCount")%>
                        </td>
                        <td style="text-align:right">
                            <%#String.Format("{0:C}", Eval("TotalAmount"))%>
                        </td>
                    </tr>
                </ItemTemplate>
                <AlternatingItemTemplate>
                    <tr class="odd">
                        <td>
                            <%# Eval("RecordId")%>
                        </td>
                        <td>
                            <%# Eval("Description")%>
                        </td>
                        <td style="text-align:right">
                            <%# Eval("TotalCount")%>
                        </td>
                        <td style="text-align:right">
                            <%#String.Format("{0:C}", Eval("TotalAmount"))%>
                        </td>
                    </tr>
                </AlternatingItemTemplate>
                <FooterTemplate>
                    <tr class="subHeadingTr" style="font-weight:bold; background-color: #e8e8e8;">
                        <td colspan="2">
                            Totals
                        </td>
                        <td style="text-align:right">
                            <%# getTotalFor("TotalCount","")%>
                        </td>
                        <td style="text-align:right">
                            <%# getTotalFor("TotalAmount","C")%>
                        </td>
                    </tr>
                    </table>
                </FooterTemplate>
            </asp:Repeater>
        </div>    
    </div>
    </form>
</body>
</html>