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Dropdown selectedIndexChange Event is calling Radiobutton selectedIndexChange event.Both controls are inside repeater

Inside my repeater control I have a radiobutton list, a dropdown list and a textbox. On selectedIndexChange event of the radiobutton, I am binding dropdown list as my dropdown values should be different for each radiobutton option.
Until this, my functionality is working perfectly. Now I want to autopopulate the textbox value based which will be selected text of dropdown but SelectedIndexChangeEvent of dropdown is calling Radiobutton's selectedIndexChange Event.
Any help on this ?
I have Autopostback set to true of dropdown.
Dropdown selectedIndexChange event is calling radiobutton selectedindexchange Event.
Code
////////////Code Behind File //////////////

Html Part of the code:
<form id="form1" runat="server">
<div>
<asp:Repeater ID="Repeater1" runat="server">
<HeaderTemplate>
<table border="1">
<tr>
<th>Name</th>
<th>Country</th>
<th>City</th>
<th>Comments</th>
</tr>
</HeaderTemplate>
<ItemTemplate>
<tr>
<td>
<asp:Label ID="lblName" Text='<%# Eval("Name") %>' runat="server" />
</td>
<td>
<asp:RadioButtonList ID="rblCountry" runat="server" AutoPostBack="true" OnSelectedIndexChanged="rblCountry_SelectedIndexChanged">
<asp:ListItem Text="United States" Value="US"></asp:ListItem>
<asp:ListItem Text="United Kingdom" Value="UK"></asp:ListItem>
<asp:ListItem Text="Australia" Value="Aus"></asp:ListItem>
</asp:RadioButtonList>
</td>
<td>
<asp:DropDownList ID="ddlCity" runat="server" AutoPostBack="true" OnSelectedIndexChanged="ddlCity_SelectedIndexChanged">
</asp:DropDownList>
</td>
<td>
<asp:TextBox ID="txtCity" runat="server"></asp:TextBox>
</td>
</tr>
</ItemTemplate>
<FooterTemplate>
</table>
</FooterTemplate>
</asp:Repeater>
</div>
</form>
code behind part:
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
PopulateList();
}
}
private void PopulateList()
{
DataTable dt = new DataTable();
dt.Columns.AddRange(new DataColumn[1] { new DataColumn("Name", typeof(string))});
dt.Rows.Add("John Hammond");
dt.Rows.Add("Mudassar Khan");
dt.Rows.Add("Suzanne Mathews");
dt.Rows.Add("Robert Schidner");
Repeater1.DataSource = dt;
Repeater1.DataBind();
}
protected void rblCountry_SelectedIndexChanged(object sender, EventArgs e)
{
RepeaterItem item = (sender as RadioButtonList).NamingContainer as RepeaterItem;
string countryName = (item.FindControl("rblCountry") as RadioButtonList).Text;
DropDownList ddlCity = item.FindControl("ddlCity") as DropDownList;
TextBox txtCity = item.FindControl("txtCity") as TextBox;
ListItem li;
if (ddlCity != null)
{
ddlCity.Items.Clear();
switch (countryName)
{
case "US":
li = new ListItem() { Text = "Chicago", Value = "Chicago" };
ddlCity.Items.Add(li);
li = new ListItem() { Text = "Washington", Value = "Washington" };
ddlCity.Items.Add(li);
break;
case "UK":
li = new ListItem() { Text = "Manchester", Value = "Manchester" };
ddlCity.Items.Add(li);
li = new ListItem() { Text = "London", Value = "London" };
ddlCity.Items.Add(li);
li = new ListItem() { Text = "Scotland", Value = "Scotland" };
ddlCity.Items.Add(li);
break;
case "Aus":
li = new ListItem() { Text = "Sydney", Value = "Sydney" };
ddlCity.Items.Add(li);
li = new ListItem() { Text = "Melbourne", Value = "Melbourne" };
ddlCity.Items.Add(li);
break;
}
if (ddlCity != null && ddlCity.SelectedItem != null)
txtCity.Text = ddlCity.SelectedItem.Text;
}
}
protected void ddlCity_SelectedIndexChanged(object sender, EventArgs e)
{
RepeaterItem item = (sender as DropDownList).NamingContainer as RepeaterItem;
DropDownList ddlCity = item.FindControl("ddlCity") as DropDownList;
TextBox txtCity = item.FindControl("txtCity") as TextBox;
txtCity.Text = ddlCity.SelectedItem.Text;
}

Dynamically give Id to textbox (Server side control) in asp:Repeater

In my <asp:Repeater></asp:Repeater> - There is one hidden field, textbox and button.
When data will be bound, then hidden filed will get User Id like below code
<asp:HiddenField ID="hide" Value='<%#Eval("UserId")%>' runat="server"/>
and ItemDataBound event will be called and in this function, i am getting value from hidden field and concatenating that value as a Id in text box. like below code
TextBox txt = (TextBox)e.Item.FindControl("txtReplyArea");
HiddenField hf = (HiddenField)e.Item.FindControl("hide");//1
txt.ID = "txtReplyArea" + hf.Value;//txtReplyArea1
Suppose only one record comes from database and their UserId is 1. Then textbox Id should be "textReplyArea1". From now, all are correct.
I am not sure, it's correct way to giving dynamic Id to repeater control but i think, it's correct.
Problem -
When i click on button and i get a items from repeater and textbox from Id by finding control from repeater then it shows null.
int areaId = int.Parse((sender as Button).CommandArgument);//1
string id="txtReplyArea"+areaId;//txtReplyArea1
foreach (RepeaterItem item in repeaterBlog.Items)
{
TextBox tb = item.FindControl(id) as TextBox;//tb = null
}
Code of aspx page
<%# Page Title="Messages" Language="C#" MasterPageFile="~/Menu.master" AutoEventWireup="true" CodeFile="Messages.aspx.cs" Inherits="Messages" %>
<asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
<div style="width:70%;">
<asp:Repeater ID="repeaterBlog" runat="server" OnItemDataBound="repeaterBlog_ItemDataBound">
<HeaderTemplate>
<table>
</HeaderTemplate>
<ItemTemplate>
<tr >
<td>
<asp:HiddenField ID="hide" Value='<%#Eval("UserId")%>' runat="server"/>
<asp:TextBox ID="txtReplyArea" runat="server" TextMode="Multiline" Columns="70" Rows="8" Visible="false"></asp:TextBox>
</td>
</tr>
<tr>
<td style="margin-left:47%;">
<asp:Button ID="btnReply" runat="server" Text="Reply" OnClick="btnReplyClicked" AutoPostBack="True" CommandArgument='<%#Eval("UserId")%>'/>
</td>
</tr>
</ItemTemplate>
<FooterTemplate>
</table>
</FooterTemplate>
</asp:Repeater>
</div>
</asp:Content>
Code of aspx.cs
SqlCommand cmd;
SqlDataReader sdr;
protected void Page_Load(object sender, EventArgs e)
{
if(!IsPostBack)
{
String cs = ConfigurationManager.ConnectionStrings["myWebsite"].ConnectionString;
using (SqlConnection con = new SqlConnection(cs))
{
cmd = new SqlCommand("select * from ContactMessage", con);
con.Open();
sdr = cmd.ExecuteReader();
repeaterBlog.DataSource = sdr;
repeaterBlog.DataBind();
con.Close();
}
}
}
public void repeaterBlog_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
{
TextBox txt = (TextBox)e.Item.FindControl("txtReplyArea");
HiddenField hf = (HiddenField)e.Item.FindControl("hide");
txt.ID = "txtReplyArea" + hf.Value;
}
}
protected void btnReplyClicked(object sender, EventArgs e)
{
int areaId = int.Parse((sender as Button).CommandArgument);
string id="txtReplyArea"+areaId;
foreach (RepeaterItem item in repeaterBlog.Items)
{
TextBox tb = item.FindControl(id) as TextBox;
}
}
}

This worked for me. Notice that I removed EnableViewState from the repeater and added OnItemDatabound event.
<asp:Repeater ID="repeaterBlog" runat="server" OnItemDataBound="repeaterBlog_ItemDataBound">
<HeaderTemplate>
<table>
</HeaderTemplate>
<ItemTemplate>
<tr>
<td>
<asp:HiddenField ID="hide" Value='<%#Eval("UserId")%>' runat="server" />
<asp:TextBox ID="txtReplyArea" runat="server" TextMode="Multiline" Columns="70" Rows="8"
Visible="false"></asp:TextBox>
</td>
</tr>
<tr>
<td style="margin-left: 47%;">
<asp:Button ID="btnReply" runat="server" Text="Reply" OnClick="btnReplyClicked" AutoPostBack="True"
CommandArgument='<%#Eval("UserId")%>' />
</td>
</tr>
</ItemTemplate>
<FooterTemplate>
</table>
</FooterTemplate>
</asp:Repeater>
protected void Page_Load(object sender, EventArgs e)
{
DataTable dt = new DataTable();
dt.Columns.Add("UserId");
DataRow dr = dt.NewRow();
dr[0] = 34;
dt.Rows.Add(dr);
repeaterBlog.DataSource = dt;
repeaterBlog.DataBind();
}
public void repeaterBlog_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
{
TextBox txt = (TextBox)e.Item.FindControl("txtReplyArea");
HiddenField hf = (HiddenField)e.Item.FindControl("hide");
txt.ID = "txtReplyArea" + hf.Value;
}
}
protected void btnReplyClicked(object sender, EventArgs e)
{
int areaId = int.Parse((sender as Button).CommandArgument);
string id = "txtReplyArea" + areaId;
foreach (RepeaterItem item in repeaterBlog.Items)
{
TextBox tb = item.FindControl(id) as TextBox;
}
}

You can try like this
<asp:TextBox ID='<%# "txtReplyArea" + Convert.ToString(Eval("UserId")%>)' runat="server" TextMode="Multiline" Columns="70" Rows="8" Visible="false"></asp:TextBox>

Show only 1 image from each group instead of showing all of them from each group

Structure of my WebPage looks something like:
<asp:Repeter>
<asp:Repeter>
<asp:Repeter>
<asp:DataList>
<asp:Image />
</asp:DataList>
</asp:Repeter>
</asp:Repeter>
</asp:Repeter>
In the output of my Webform, I get all the images in the DataList control. But I want to display just 1st Image from each group.
Here is my code:
.aspx:
<asp:Repeater ID="ParentRepeater" runat="server">
<ItemTemplate>
<table>
<tr>
<td>
<asp:Image ID="imgMinimizeCategory" runat="server" ImageUrl="~/Images/Minimize.jpg" />
</td>
<td>
<asp:Label ID="lblCategory" runat="server" Text='<%# Eval("ProductName")%>' />
</td>
</tr>
<tr>
<td></td>
<td>
<asp:Repeater ID="ChildRepeater" runat="server" DataSource='<%# Eval("Children") %>'>
<ItemTemplate>
<table>
<tr>
<td>
<asp:Image ID="imgMinimizeGroup" runat="server" ImageUrl="~/Images/Minimize.jpg" />
</td>
<td>
<asp:Label ID="lblGroup" runat="server" Text='<%# Eval("ProductName")%>' />
</td>
</tr>
<tr>
<td></td>
<td>
<asp:Repeater ID="ChildrenRepeater" runat="server" DataSource='<%# Eval("Children") %>'>
<ItemTemplate>
<asp:DataList ID="dlProductImages" runat="server" DataSource='<%#Eval("Images") %>' DataKeyField="ImageId"
RepeatColumns="6">
<ItemTemplate>
<asp:Image ID="imageProductImage" runat="server" Height="180px" ImageUrl='<%# Eval("ImageUrl") %>' Width="180px" />
</ItemTemplate>
</asp:DataList>
</ItemTemplate>
</asp:Repeater>
</td>
</tr>
</table>
</ItemTemplate>
</asp:Repeater>
</td>
</tr>
</table>
</ItemTemplate>
</asp:Repeater>
.aspx.cs:
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
MenuItem SelectedMenuItemInMaster = Session["SelectedMenuItem"] as MenuItem;
ParentRepeater.DataSource = GetProducts(SelectedMenuItemInMaster.Value);
ParentRepeater.DataBind();
}
}
private List<Product> GetProducts(string selectedValue)
{
List<Product> ProductsOfSelectedMenuItem = new List<Product>();
string cs = ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString;
SqlConnection con = new SqlConnection(cs);
SqlDataAdapter da = new SqlDataAdapter("spGetMenuData", con);
DataSet ds = new DataSet();
da.Fill(ds);
foreach (DataRow dr in ds.Tables[0].Rows)
{
if (dr["ParentID"].ToString().Trim() == selectedValue)
{
Product item = new Product();
item.ProductName = dr["ProductName"].ToString();
item.ProductId = (int)dr["ProductId"];
item.ParentId = (int)dr["ParentId"];
foreach (DataRow drChild in ds.Tables[0].Rows)
{
if (drChild["ParentID"].ToString() == dr["ProductId"].ToString())
{
GetChildItems(ds, drChild, item);
}
}
ProductsOfSelectedMenuItem.Add(item);
}
}
SqlDataAdapter daImages = new SqlDataAdapter("Select * from Images", con);
DataSet dsImages = new DataSet();
daImages.Fill(dsImages);
foreach (Product p in ProductsOfSelectedMenuItem)
{
if (p.Children != null)
{
foreach (Product child in p.Children)
{
foreach (Product c in child.Children)
{
foreach (DataRow drImages in dsImages.Tables[0].Rows)
{
if (c.ProductId == (int)drImages["ProductId"])
{
if (c.Images == null)
{
c.Images = new List<Image>();
}
c.Images.Add(new Image() { ImageId = (int)drImages["ImageId"], ImageUrl = drImages["ImageUrl"].ToString(), ProductId = (int)drImages["ProductId"] });
}
}
}
}
}
}
return ProductsOfSelectedMenuItem;
}
private static void GetChildItems(DataSet ds, DataRow dr, Product item)
{
Product childItem = new Product();
childItem.ProductName = dr["ProductName"].ToString();
childItem.ProductId = (int)dr["ProductId"];
childItem.ParentId = (int)dr["ParentId"];
foreach (DataRow drChild in ds.Tables[0].Rows)
{
if (drChild["ParentID"].ToString() == dr["ProductId"].ToString())
{
GetChildItems(ds, drChild, childItem);
}
}
if (item.Children == null)
{
item.Children = new List<Product>();
}
item.Children.Add(childItem);
}
I know, you are thinking that this is a very silly question as I am adding all the images to the collection. But let me explain you. I will use all the images in my next programming step. So, I don't want a collection that does not get images. In short, I want all the images in the collection. When I declare DataSource='<%# Eval("Images")%>' in DataList Tag, I would like to query the collection here. But I don't know how.....
Update:

You can implement a method in code behind that you refer to in the DataSource attribute, and have the method return a subset of the images based on your needs.
DataSource='<%# MyFilteredImageCollection(Eval("Images")) %>'

Having problems in accessing textbox in listview

I am getting an error("input string was not in a correct format") every time I click the lnkUpdate button. Am i missing something? I can't find what's wrong with the codes in the updating event
aspx
<table class="table table-bordered table-hover table-responsive">
<thead>
<tr>
<th>Product ID</th>
<th>Product Name</th>
<th>Received</th>
<th>Remaining</th>
<th>Ordered</th>
<th></th>
</tr>
</thead>
<tbody>
<asp:ListView ID="lvSODetails" runat="server"
onitemcanceling="lvSODetails_ItemCanceling"
onitemediting="lvSODetails_ItemEditing"
onitemupdating="lvSODetails_ItemUpdating" >
<ItemTemplate>
<tr>
<td><%# Eval("ProductID") %></td>
<td><%# Eval("ProductName") %></td>
<td><%# Eval("Received") %></td>
<td><%# Eval("Remaining")%></td>
<td><%# Eval("Quantity") %></td>
<td>
<asp:LinkButton ID="lnkEdit" runat="server"
class="glyphicon glyphicon-pencil" CommandName="Edit" />
</td>
</tr>
</ItemTemplate>
<EditItemTemplate>
<asp:Panel ID="pnlDetails" runat="server" DefaultButton="lnkUpdate">
<tr>
<td><asp:Label ID="lblID" runat="server" Text='<%# Eval("ProductID") %>' /></td>
<td><%# Eval("ProductName") %></td>
<td><asp:TextBox ID="txtQtyReceived" runat="server" /></td>
<td><asp:Label ID="lblRemaining" runat="server" Text='<%# Eval("Remaining") %>' /></td>
<td><%# Eval("Quantity") %></td>
<td>
<asp:LinkButton ID="lnkUpdate" runat="server"
class="glyphicon glyphicon-ok" CommandName="Update" />
<asp:LinkButton ID="lnkCancel" runat="server"
class="glyphicon glyphicon-remove" CommandName="Cancel" />
</td>
</tr>
</asp:Panel>
</EditItemTemplate>
</asp:ListView>
</tbody>
</table>
c# code
protected void lvSODetails_ItemEditing(object sender, ListViewEditEventArgs e)
{
lvSODetails.EditIndex = e.NewEditIndex;
GetInfo();
GetDetails();
}
protected void lvSODetails_ItemCanceling(object sender, ListViewCancelEventArgs e)
{
lvSODetails.EditIndex = -1;
GetInfo();
GetDetails();
}
protected void lvSODetails_ItemUpdating(object sender, ListViewUpdateEventArgs e)
{
string ProdID = (lvSODetails.Items[e.ItemIndex].FindControl("lblID") as Label).Text;
string Received = (lvSODetails.Items[e.ItemIndex].FindControl("txtQtyReceived") as TextBox).Text;
string Remaining = (lvSODetails.Items[e.ItemIndex].FindControl("lblRemaining") as Label).Text;
if (int.Parse(Received) < 0) // <~ this is where the code stops (error"input string was not in a correct format")
{
error.Visible = true;
lblError.Text = "Items received must not be lower than zero";
}
else if (int.Parse(Received) >= 0 && int.Parse(Received) <= int.Parse(Remaining))
{
SODetails = (DataTable)Session["sodelivery"];
foreach (DataRow row in SODetails.Rows)
{
if (row["ProductID"].ToString() == ProdID)
{
row["Received"] = Received;
break;
}
}
}
lvSODetails.EditIndex = -1;
GetInfo();
GetDetails();
}
~~~~ Edit ~~~~
listview databinding code
void GetDetails()
{
if (SODetails == null)
{
con.Open();
SqlCommand cmd = new SqlCommand();
cmd.Connection = con;
cmd.CommandText = "SELECT sod.ProductID, p.ProductName, sod.SOQtyReceived AS Received, " +
"(sod.SOQtyOrdered - sod.SOQtyReceived) AS Remaining, sod.SOQtyOrdered AS Quantity FROM SODetails AS sod " +
"INNER JOIN Products AS p ON sod.ProductID=p.ProductID WHERE sod.SONo=#SONo";
cmd.Parameters.Add("#SONo", SqlDbType.Int).Value = Request.QueryString["ID"].ToString();
SqlDataAdapter data = new SqlDataAdapter(cmd);
SODetails = new DataTable();
data.Fill(SODetails);
DataRow[] rowList = SODetails.Select();
foreach (DataRow dr in rowList)
{
dr["Received"] = "0";
}
lvSODetails.DataSource = SODetails;
lvSODetails.DataBind();
con.Close();
Session["sodelivery"] = SODetails;
}
else
{
lvSODetails.DataSource = SODetails;
lvSODetails.DataBind();
Session["sodelivery"] = SODetails;
}
}

Your problem isn't that you can't access the TextBox.
Use int.TryParse instead of int.Parse since you are reading user input.
int received;
if (!int.TryParse(Received, out received) || received < 0)
{
error.Visible = true;
lblError.Text = "Items received must not be lower than zero";
}

Repeater and add columns to header and itemtemplate on page load

I haven't used repeaters for much more than showing data from a datatable.
I am building a grid that that shows a list of users and columns of roles that the user has been assigned, shown with checkboxes (shown with true/false below but pretent they are checkboxes).
ex.
|Rep Name|Caller|Closer|Manager|SuperUser|
|Bob |True  |true | false | false |
|Tom |false |false |True | True |
Basically using it for roles management.
However the roles may change later on so I want to load the roles(headers and items) dynamically into the repeater.
I am not sure how to do this or if it is even possible.
I figure you grab a list of current role possibilities and load them into the headertemplate but I am not sure how to match those with the itemtemplate and how to create checkboxes and place them in the itemtemplate.
Sorry if it is a rudementary question.... I appreciate any advice!
Datatable example of data that I am going to get... though I will also return ids for roles and users that are not shown here.
DataTable dt = new DataTable();
DataColumn dc = new DataColumn();
dc.DataType = Type.GetType("System.String");
dc.ColumnName = "RepName";
dt.Columns.Add(dc);
dc = new DataColumn();
dc.DataType = Type.GetType("System.Boolean");
dc.ColumnName = "Caller";
dt.Columns.Add(dc);
dc = new DataColumn();
dc.DataType = Type.GetType("System.Boolean");
dc.ColumnName = "closer";
dt.Columns.Add(dc);
dc = new DataColumn();
dc.DataType = Type.GetType("System.Boolean");
dc.ColumnName = "Admin";
dt.Columns.Add(dc);
dc = new DataColumn();
dc.DataType = Type.GetType("System.Boolean");
dc.ColumnName = "SuperUser";
dt.Columns.Add(dc);
DataRow row;
row = dt.NewRow();
row["RepName"] = "Joe";
row["Caller"] = true;
row["closer"] = false;
row["Admin"] = true;
row["SuperUser"] = false;
dt.Rows.Add(row);
row = dt.NewRow();
row["RepName"] = "Bob";
row["Caller"] = true;
row["closer"] = false;
row["Admin"] = true;
row["SuperUser"] = false;
dt.Rows.Add(row);
row = dt.NewRow();
row["RepName"] = "Tom";
row["Caller"] = true;
row["closer"] = false;
row["Admin"] = true;
row["SuperUser"] = false;
dt.Rows.Add(row);

Use nested Repeaters: the outer Repeater is for rows and has a HeaderTemplate and ItemTemplate which contain inner Repeaters for header and checkbox columns respectively. Something like this:
<asp:Repeater runat="server" ID="rowRepeater" OnItemDataBound="rowRepeater_ItemBound">
<HeaderTemplate>
<table>
<tr>
<asp:Repeater runat="server" ID="headerRepeater">
<ItemTemplate>
<th>
<%# Container.DataItem %>
</th>
</ItemTemplate>
</asp:Repeater>
</tr>
</HeaderTemplate>
<ItemTemplate>
<tr>
<td><asp:Label runat="server" ID="lblUserName" Text='<%# Eval("Key") %>' /></td>
<asp:Repeater runat="server" ID="columnRepeater">
<ItemTemplate>
<td>
<asp:HiddenField runat="server" ID="hfRoleIndex" Value='<%# Container.ItemIndex %>' />
<asp:CheckBox runat="server" ID="cbColumnValue" Checked='<%# Container.DataItem %>' OnCheckedChanged="cbColumnValue_CheckedChanged" AutoPostBack="true" />
</td>
</ItemTemplate>
</asp:Repeater>
</tr>
</ItemTemplate>
<FooterTemplate>
</table>
</FooterTemplate>
</asp:Repeater>
and in your code behind:
Dictionary<string, bool[]> userRoles = new Dictionary<string, bool[]>(){
{"Bob", new bool[]{true,true,false,false}},
{"Tim",new bool[]{false,false,true,true}},
{"John",new bool[]{false,true,false,true}}
};
string[] headings = { "Rep Name", "Caller", "Closer", "Manager", "SuperUser" };
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
rowRepeater.DataSource = userRoles;
rowRepeater.DataBind();
}
}
protected void rowRepeater_ItemBound(object sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Header)
{
Repeater headerRepeater = e.Item.FindControl("headerRepeater") as Repeater;
headerRepeater.DataSource = headings;
headerRepeater.DataBind();
}
else if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
{
Repeater columnRepeater = e.Item.FindControl("columnRepeater") as Repeater;
columnRepeater.DataSource = ((KeyValuePair<string, bool[]>)e.Item.DataItem).Value;
columnRepeater.DataBind();
}
}
protected void cbColumnValue_CheckedChanged(object sender, EventArgs e)
{
CheckBox cb = sender as CheckBox;
HiddenField hf = cb.Parent.FindControl("hfRoleIndex") as HiddenField;
int roleIndex = int.Parse(hf.Value); // now you have the column identifier
Label lbl = cb.Parent.Parent.Parent.FindControl("lblUserName") as Label;
string userName = lbl.Text; //now you have the row identifier
//now you can update your data source
userRoles[userName][roleIndex] = cb.Checked;
}

I'll try something like this:
<asp:GridView ID="OrdersGV" runat="server" AutoGenerateColumns="False">
<Columns>
<asp:BoundField DataField="UserName" />
<asp:TemplateField>
<ItemTemplate>
<asp:ListView ID="NewsLV" runat="server">
<ItemTemplate>
<td id="Td1" runat="server" valign="top" style="width: 30px;">
<asp:Label ID="Label1" runat="server" Text='<%# Eval("RoleName") %>' Visible='<%# Container.DataItemIndex == 0%>'></asp:Label>
<div style="padding: 2px;">
<asp:CheckBox ID="CheckBox1" runat="server" Checked='<%# Eval("IsRoleSelected") %>' />
</div>
</td>
</ItemTemplate>
<LayoutTemplate>
<table id="Table1" runat="server" border="0" style="">
<tr id="itemPlaceholderContainer" runat="server">
<td id="itemPlaceholder" runat="server">
</td>
</tr>
</table>
</LayoutTemplate>
</asp:ListView>
</ItemTemplate>
</asp:TemplateField>
</Columns>