In this post, I will show you how to shuffle the row of any collection in C#. In this post, I am using DataSet, but you can apply this logic anywhere like List. Check out the following code snippet.
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Randomize.aspx.cs"
Inherits="Randomize" %>
<!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>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:GridView ID="grd" runat="Server"></asp:GridView>
</div>
</form>
</body>
</html>
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class Randomize : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
grd.DataSource = DataSetUtilities.RandomizeDataTable(CreateDS().Tables[0]);
grd.DataBind();
}
private DataSet CreateDS()
{
DataSet ds;
if (Session["DataList_ParentChild"] == null)
{
ds = new DataSet();
DataTable dt = new DataTable("Company");
DataRow dr;
dt.Columns.Add(new DataColumn("ID", typeof(Int32)));
dt.Columns.Add(new DataColumn("CompanyName", typeof(string)));
dt.Columns.Add(new DataColumn("Address", typeof(string)));
dt.Columns.Add(new DataColumn("Name", typeof(string)));
dt.Columns.Add(new DataColumn("Dept", typeof(string)));
for (int i = 1; i < 10; i++)
{
dr = dt.NewRow();
dr[0] = i;
dr[1] = "Company " + i;
dr[2] = "Address " + i;
dr[3] = "Manager name";
dr[4] = "Adminstration";
dt.Rows.Add(dr);
}
ds.Tables.Add(dt);
DataColumn[] Parent_PKColumns = new DataColumn[1];
Parent_PKColumns[0] = dt.Columns["ID"];
dt.PrimaryKey = Parent_PKColumns;
}
else
{
ds = (DataSet)Session["DataList_ParentChild"];
}
return ds;
}
}
public static class DataSetUtilities
{
static Random _rand = new Random();
public static DataView RandomizeDataTable(DataTable dt)
{
// Create array of indices and populate with ordinal values
int[] indices = new int[dt.Rows.Count];
for (int i = 0; i < indices.Length; i++)
indices[i] = i;
// Knuth-Fisher-Yates shuffle indices randomly
for (int i = indices.Length - 1; i > 0; i--)
{
int n = _rand.Next(i + 1);
int tmp = indices[i];
indices[i] = indices[n];
indices[n] = tmp;
}
// Add new column to data table (if it's not there already)
// to store shuffle index
if (dt.Columns["rndSortId"] == null)
dt.Columns.Add(new DataColumn("rndSortId", typeof(int)));
int rndSortColIdx = dt.Columns["rndSortId"].Ordinal;
for (int i = 0; i < dt.Rows.Count; i++)
dt.Rows[i][rndSortColIdx] = indices[i];
DataView dv = new DataView(dt);
dv.Sort = "rndSortId";
return dv;
}
}