CODEWITHSUNDEEP
c#asp.net
Josimari Martarelli
Josimari Martarelli

Reputation:

Asp.Net(C#) Cross-Page Postback

I have tryed access values from controls in page1 to page2 using cross page postback like following:

My page1(Default.aspx) has a LinkButton where I store some information when the page is first loaded:

<asp:LinkButton ID="btnNoticia" 
runat="server" Text="Leia ++" 
CommandName="NoticiaID" 
CommandArgument='<%# Eval("NoticiaID")%>' 
EnableViewState="True" 
PostBackUrl="Noticias.aspx" 
/>

In my page2(Noticias.aspx) I'm recovering the values from "btnNoticia" like that:

LinkButton btnLeiaMaisDefault = (LinkButton)Page.PreviousPage.FindControl("btnNoticia");

But it can't find the control posted by the previous page. I'm getting a null value for "btnLeiaMaisDefault".

Some idea?

PS: LinkButton ID="btnNoticia" in page1 is inside an UpdatePanel.

Thank you

Josi

Upvotes: 0

Views: 1735

Answers (3)

Niks
Niks

Reputation: 1007

Navigate your url like

PostBackUrl="~/Default.aspx"

Code as

protected void Page_Load(object sender, System.EventArgs e)

{

    TextBox pvProductID = (TextBox)PreviousPage.FindControl("TextBox1");

    TextBox pvProductName = (TextBox)PreviousPage.FindControl("TextBox2");
    Label1.Text ="You came from: "+ PreviousPage.Title.ToString();        
    Label2.Text = "Product ID: " + pvProductID.Text.ToString();
    Label2.Text += "<br />Product Name: " + pvProductName.Text.ToString();

    string imageSource = "~/Images/" + pvProductID.Text + ".jpg";
    Image1.ImageUrl = imageSource;
    Image1.BorderWidth = 2;
    Image1.BorderColor = System.Drawing.Color.DodgerBlue;
}

I tried ....It works...

Upvotes: 1

Tarik
Tarik

Reputation: 81721

You can't simply use FindControl like that. Because your control may be under another control so you need a recursive function to iterate all the controls and their descendants to get the specified control.

You can put your linkbutton control under a panel control and access it with this way :

LinkButton btnLeiaMaisDefault = (LinkButton)Page.PreviousPage.Panel1.FindControl("btnNoticia");

or other way is using recursive function :

private Control FindControlRecursive(Control root, string id) 
{ 
    if (root.ID == id)
    { 
        return root; 
    } 

    foreach (Control c in root.Controls) 
    { 
        Control t = FindControlRecursive(c, id); 
        if (t != null) 
        { 
            return t; 
        } 
    } 

    return null; 
}

Upvotes: 1

Pankaj Kumar
Pankaj Kumar

Reputation: 1768

Try this code...it is working on my side.......

if (Page.PreviousPage!=null)
        {
            LinkButton btnLeiaMaisDefault = (LinkButton)Page.PreviousPage.FindControl("btnNoticia");
        }

hope it helps.

Upvotes: -1

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