How do I access form control from class library in ASP NET

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Hey all,
let say i have a panel or text control in form, normally it is possible to access controls by id but how can i access control from class library.

What I have tried:

C#

public class FormDesign
{
public void fun()
{
textbox1.text="some text";   //notworking
foreach(control ct in panel)    //not working
{
//some code
}
}
}

Posted 8-Sep-20 15:01pm

Aftab Iqbal Clips

Updated 9-Sep-20 0:17am

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Dave Kreskowiak 8-Sep-20 22:15pm

Is this an ASP.NET app or Windows Forms?

Aftab Iqbal Clips 8-Sep-20 23:44pm

its an ASP.NET application

2 solutions

Solution 1

Check that the TextBox has runat="server" in it's HTML:

ASP.NET

<asp:TextBox ID="textbox1" Columns="2" MaxLength="3" Text="1" runat="server"/>

The ID will need to match the name you use in the C# code.
The Panel will need the same, but you will also need to access it's Controls collection, and remember that C# is case sensitive: "control" is not the same as "Control":

C#

foreach (Control ct in panel.Controls)

And by the way: "It's not working" is one of the most useless problem descriptions we get: it tells us absolutely nothing about the problem. We don't know if you get an error message, or the wrong data, or even that that code compiles successfully!
Remember that we can't see your screen, access your HDD, or read your mind - we only get exactly what you type to work with.
So tell us what happens when you run that code, what you expected to happen, how you checked what happened. Help us to help you!

Posted 8-Sep-20 19:56pm

OriginalGriff

Comments

Aftab Iqbal Clips 9-Sep-20 2:11am

as i mentioned in question i want to access asp page control from class
there is textbox inside panel
panel is added with markup
textbox is added programmatically

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F-ES Sitecore · Accepted Answer · 2020-09-09T00:18:00

You can't access controls from a class library as the controls are defined on the code-behind of the aspx file and populated for you by asp.net. If your class really must run from asp.net controls then set up properties for those controls

C#

public class FormDesign
{
    public Panel MyPanel {get; set;}

    public void Fun()
    {
        foreach(Control ct in this.MyPanel)
        {

When you create FormDesign in your code-behind class populate the relevant properties

C#

var formDesign = new FormDesign();
formDesign.MyPanel = panel1;
formDesign.Fun();

You can also pass the controls in as params to Fun, it all depends on what your code needs to do.