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binding an asp.net checkbox on serverside

I have an search functionality in which the checkbox should come as checked or unchecked based on the data these check boxes were multiple and I am doing it on server side here I have is the code
<asp:CheckBox ID="AApBlue" runat="server"Checked='<%#GetBoolean(Eval("blueFlag").ToString()) %>'/>Blue
.cs file
protected Boolean GetBoolean(string val)
{
return val == "Y" ? true : false;
}
I am getting an error:
object reference null pointer exception
Please help!

Method 1:
You should try ItemDataBound event, add a Label and set it as visible false:
<asp:CheckBox ID="AApBlue" runat="server" />
<asp:Label ID="Label1" Text='<% # Eval("blueFlag") %>' Visible="false" runat="server" >
</asp:Label>
.CS File:
protected void DataList1_ItemDataBound(object sender, DataListItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item ||
e.Item.ItemType == ListItemType.AlternatingItem)
{
CheckBox chk = e.Item.FindControl("AApBlue") as CheckBox;
Label lbl = e.Item.FindControl("Label1") as Label;
chk.Checked = (lbl.Text == "Y") ? true : false;
}
}
Note: Don't forget to add OnItemDataBound event in DataList.
<asp:DataList ID="DataList1" OnItemDataBound="DataList1_ItemDataBound" runat="server">
Method 2:
You can use ternary operator in checkbox checked as:
Checked='<% # (Eval("blueFlag").ToString() == "Y") ? true : false %>'

Items are looping all items in Repeater's ItemDataBound event

I have a normal Repeater Control in my aspx page
<asp:Repeater ID="rpt1" runat="server" OnItemDataBound="rpt1_ItemDataBound">
<ItemTemplate>
<asp:CheckBox ID="chks" runat="server" />
<asp:TextBox ID="txtName" runat="server" CssClass="form-control" Text='<%# DataBinder.Eval(Container,"DataItem.Name").ToString()%>'></asp:TextBox><asp:Label ID="lblValue" runat="server" Visible="false" Text='<%# DataBinder.Eval(Container,"DataItem.Id").ToString() %>'></asp:Label>
</ItemTemplate>
</asp:Repeater>
On the button click I'm binding data to the Repeater as
rpt1.DataSource = GetData();
rpt1.DataBind();
After binding the ItemDataBound event is called. In that I'm looping through the repeater items for some manipulations
protected void rpt1_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
foreach (RepeaterItem item in rpt1.Items)
{
if (item.ItemType == ListItemType.Item || item.ItemType == ListItemType.AlternatingItem)
{
string val = ((Label)item.FindControl("lblValue")).Text;
// Some Stuff
}
}
}
The problem is that the loop is getting started from first every time.
For Ex if my data is as 1 2 3 so on.....
It is iterarting as
1
1 2
1 2 3
How can I make it as
1
2
3
What am I doing wrong

ItemDataBound is already called for every item in the repeater, so you don't need a loop there.
protected void rpt1_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
{
string val = ((Label)e.Item.FindControl("lblValue")).Text;
// Some Stuff
}
}
Side-Note: that applies to all Data-Bound Web Server Controls.

Repeater which Event to use to find a control inside the repeater

I use asp.net and c#4.
I have a repeater within inside a HyperLink Control.
I need to Find the HyperLink Control and change some of its properties with some logic before rendering it on the page.
With my code here posted I get a null value for the control so I'm not able to get it.
Any idea what I'm doing wrong? Thanks for your time on this.
<asp:Repeater ID="RepeaterEditorsChoice" runat="server" DataSourceID="ObjectDataSourceEditorsChoice"
OnItemCreated="RepeaterEditorsChoice_ItemCreated" OnItemDataBound="RepeaterEditorsChoice_ItemDataBound">
<HeaderTemplate>
<ul>
</HeaderTemplate>
<ItemTemplate>
<li>
<asp:HyperLink ID="uxLink" runat="server"></asp:HyperLink>
</li>
</ItemTemplate>
<FooterTemplate>
</ul>
</FooterTemplate>
</asp:Repeater>
CODE BEHIND:
protected void RepeaterEditorsChoice_ItemCreated(object sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.AlternatingItem || e.Item.ItemType == ListItemType.Item)
{
HyperLink myLink = (HyperLink)((Repeater)sender).FindControl("uxLInk"); // ERROR: it is null
dynamic o = e.Item.DataItem;
if (o.TypeContent == "AR")
{
myLink.Text = #"'<%# Eval(\""Title\"") %>'";
myLink.NavigateUrl = #"'<%# GetRouteUrl(""ArticleDetails"", new {ContentId = Eval(""ContentId""), TitleUrl = Eval(""TitleUrl"")}) %>'";
}
if (o.TypeContent == "BP")
{
myLink.Text = #"'<%# Eval(\""Title\"") %>'";
myLink.NavigateUrl = #"'<%# GetRouteUrl(""BlogPostDetails"", new {ContentId = Eval(""ContentId""), TitleUrl = Eval(""TitleUrl"")}) %>'";
}
}
}

On item data bound
then just (YourClass)e.Item.FindControl("its name");

C# Pass textbox content via CommandArgument in Repeater

<asp:Repeater ID="Cartridges" runat="server" onitemcommand="Cartridges_ItemCommand">
<ItemTemplate>
<p class="cartprice"><%#String.Format("{0:C}", Eval("Price"))%></p>
<hr class="hr4" />
<p class="cartqty">QTY <asp:TextBox ID="cartQty" Text="0" runat="server"></asp:TextBox> </p>
<div class="cartbuy2"><asp:LinkButton ID="buy" runat="server" CommandName="AddtoCart" CommandArgument=<%#Eval("cartID") %> Text="Buy"></asp:LinkButton></div>
</ItemTemplate>
</asp:Repeater>
How can I pass the textbox value within CommandArgument? Sorry totally lost...

Did you try: CommandArgument='<%#Eval("cartID") %>'
this is different from yours as it is surrounded by a single quote, I guess this is the correct syntax.

Use FindControl to get other items in the repeater Item. For Example:
protected void repeater_ItemCommand(object sender, RepeaterCommandEventArgs e)
{
LinkButton lb = (LinkButton)e.CommandSource;
string textBoxValue = ((TextBox)lb.Parent.FindControl("cartQty")).Text;
}

you need to bind the cartId to the linkbutton onItemDataBound and then access it onItemCommand, I have modified code for you, give this a go
<asp:Repeater ID="Cartridges" runat="server" onitemcommand="Repeater_OnItemCommand" OnItemDataBound="Repeater_OnItemDataBound">
<ItemTemplate>
<p class="cartprice"><%#String.Format("{0:C}", Eval("Price"))%></p>
<hr class="hr4" />
<p class="cartqty">QTY <asp:TextBox ID="cartQty" Text="0" runat="server"></asp:TextBox> </p>
<div class="cartbuy2"><asp:LinkButton ID="buy" runat="server" CommandName="AddtoCart" Text="Buy"></asp:LinkButton></div>
your onItemdatabound should look like this
protected void Repeater_OnItemDataBound(object sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
{
//your code...
LinkButton add = (LinkButton)e.Item.FindControl("buy");
add.CommandArgument = cartID.ToString();
}
and then you can access the text box on item command like this
protected void Repeater_OnItemCommand(object source, RepeaterCommandEventArgs e)
{
if (e.CommandName == "AddtoCart")
{
LinkButton btnEdit = (LinkButton)e.CommandSource;
if (btnEdit != null)
{
string editId = btnEdit.CommandArgument;
string text = ((TextBox)e.Item.FindControl("cartQty")).Text;
//do some stuff with your cartid and quantity
}
}
}
You can also extend your code with edit/delete command arguments by adding more linkbuttons and binding them to the correct command and then accessing them in on item command
Thanks

Can't find control within asp.net repeater?

I have the following repeater below and I am trying to find lblA in code behind and it fails. Below the markup are the attempts I have made:
<asp:Repeater ID="rptDetails" runat="server">
<HeaderTemplate>
<table>
</HeaderTemplate>
<ItemTemplate>
<tr>
<td><strong>A:</strong></td>
<td><asp:Label ID="lblA" runat="server"></asp:Label>
</td>
</tr>
</ItemTemplate>
</asp:Repeater>
</table>
First I tried,
Label lblA = (Label)rptDetails.FindControl("lblA");
but lblA was null
Then I tried,
Label lblA = (Label)rptDetails.Items[0].FindControl("lblA");
but Items was 0 even though m repeater contains 1 itemtemplate

You need to set the attribute OnItemDataBound="myFunction"
And then in your code do the following
void myFunction(object sender, RepeaterItemEventArgs e)
{
Label lblA = (Label)e.Item.FindControl("lblA");
}
Incidentally you can use this exact same approach for nested repeaters. IE:
<asp:Repeater ID="outerRepeater" runat="server" OnItemDataBound="outerFunction">
<ItemTemplate>
<asp:Repeater ID="innerRepeater" runat="server" OnItemDataBound="innerFunction">
<ItemTemplate><asp:Label ID="myLabel" runat="server" /></ItemTemplate>
</asp:Repeater>
</ItemTemplate>
</asp:Repeater>
And then in your code:
void outerFunction(object sender, RepeaterItemEventArgs e)
{
Repeater innerRepeater = (Repeater)e.Item.FindControl("innerRepeater");
innerRepeater.DataSource = ... // Some data source
innerRepeater.DataBind();
}
void innerFunction(object sender, RepeaterItemEventArgs e)
{
Label myLabel = (Label)e.Item.FindControl("myLabel");
}
All too often I see people manually binding items on an inner repeater and they don't realize how difficult they're making things for themselves.

I just had the same problem.
We are missing the item type while looping in the items. The very first item in the repeater is the header, and header does not have the asp elements we are looking for.
Try this:
if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
{Label lblA = (Label)rptDetails.Items[0].FindControl("lblA");}

Code for VB.net
Protected Sub rptDetails_ItemDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.RepeaterItemEventArgs) Handles rptDetails.ItemDataBound
If e.Item.ItemType = ListItemType.AlternatingItem Or e.Item.ItemType = ListItemType.Item Then
Dim lblA As Label = CType(e.Item.FindControl("lblA"), Label)
lblA.Text = "Found it!"
End If
End Sub

Investigate the Repeater.ItemDataBound Event.

You should bind first.
for example)
rptDetails.DataSource = dataSet.Tables["Order"];
rptDetails.DataBind();