asp.net web forms best practice to retrieve dynamic server control values
Posted
by Andrew Florko
on Stack Overflow
See other posts from Stack Overflow
or by Andrew Florko
Published on 2010-05-24T21:07:01Z
Indexed on
2010/05/24
21:11 UTC
Read the original article
Hit count: 266
ASP.NET
|server-side-controls
I populate web form with dynamic list of exams from database. I want user to enter examination marks for each exam. There is list of exam titles and textbox near each title.
I create list with repeater control:
<asp:Repeater ID="rptExams" runat="server" onitemdatabound="rptExams_ItemDataBound" >
<ItemTemplate>
<tr>
<td>
<asp:Literal runat="server" ID="ltTitle"/>
</td>
<td>
<asp:HiddenField runat="server" ID="hfId"/>
<asp:Textbox runat="server" ID="tbMark"/>
</td>
</tr>
</ItemTemplate>
</asp:Repeater>
And bind data to repeater on page_init:
class Exam
{
public int Id { get; set;}
public string Title { get; set;}
}
...
// this list is retrieved from database actually
Exam[] Exams = new Exam[]
{
new Exam { Id = 1, Title = "Math"},
new Exam { Id = 2, Title = "History"}
};
...
protected void Page_Init(object sender, EventArgs e)
{
rptExams.DataSource = Exams;
rptExams.DataBind();
}
So far so good. Then I have to retrieve data on postback. I have two ways but both of them looks ugly. Idea is to store dynamically created databounded controls on ItemDataBoundEvent in Page_Init stage, and process their values in Page_Load stage. It looks like this:
private Dictionary<HiddenField, TextBox> Id2Mark = new Dictionary<HiddenField, TextBox>();
protected void rptExams_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
...
if (IsPostBack)
{
var tbMark = (TextBox)e.Item.FindControl("tbMark");
var hfId = (HiddenField)e.Item.FindControl("hfId");
// store dynamically created controls
Id2Mark.Add(hfId, tbMark);
}
...
}
protected void Page_Load(object sender, EventArgs e)
{
if (IsPostBack)
{
foreach (var pair in Id2Mark)
{
int examId = Int32.Parse(pair.Key.Value);
string mark = pair.Value.Text;
// PROCESS
}
...
I'm completely sure there is a better way to retrieve data from dynamically created controls. Thank you in advance!
© Stack Overflow or respective owner