CODEWITHSUNDEEP
asp.netuser-controlsevent-handling
Episodex
Episodex

Reputation: 4559

How to change property of UserControl on PostBack?

Let's say I have a page with my custom UserControl (containing only asp:Literal and some string property) and a button. Now I want to change Literal's text on button click, so I change my control's string property in button clicked event. Like this:

//in aspx
protected void Button1_Click(object sender, EventArgs e)
{
    testControl.Text = "triggered";
}

The problem is my Literal remains unchanged because Page_Load event fires first and creates my custom control, then Button_Clicked fires and changes property but as control is already created, it does nothing. This is my control's code behind:

public partial class TestControl : System.Web.UI.UserControl
{
    public string Text { get; set; } }

    protected void Page_Load(object sender, EventArgs e)
    {
        lblTest.Text = Text;
    }
}

I figured out that if I move any logic in custom control from Page_Load to property setter it will change like intended. Like this:

public string Text { get { return lblTest.Text; } set { lblTest.Text = value; } }

Is there any other (better) way to do this? My real problem involves much more complicated controls than described here, but problems remains the same: on any postback all properties set in event handlers are ignored.

Upvotes: 0

Views: 2198

Answers (2)

Episodex
Episodex

Reputation: 4559

Moving all logic from Page_Load to Page_PreRender solved the problem. Now properties are set before logic executes. I'll wait for other answers to check if there is better solution and if there are any drawbacks of using Page_PreRender.

Upvotes: 3

Tom Robinson
Tom Robinson

Reputation: 8528

This video might help: How Do I: Persist the State of a User Control During a Postback

Upvotes: 0

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