ASP ListBox wrong ID

Question

User-902956371 posted

So I have this 2 ListBox, everything works if I use only the second one, the problems start after clicking the first one, happens that the next time I click the second, it gets the ID of the firstone...

so..

click 2 -> Works

click 2 -> Works

click 1 -> works

click 1 -> works

click 2 -> I get the ID of the first one....

and I have this problem with all the browsers...

<div class="col-sm-3" style="overflow:auto;">
    <label for="lbRoot" class="control-label">Root Cause</label> 
    <asp:ListBox ID="lbRoot" 
        runat="server" 
        CssClass="form-control" 
        Height="250px" 
        Width="170px"
        DataTextField="name" 
        DataValueField="file"
        OnSelectedIndexChanged="Index_Changed"
        AutoPostBack="true">
    </asp:ListBox>
</div>


<div class="col-sm-3" style="overflow:auto;">
    <label for="lbEvidence" class="control-label ">Follow Up</label>
    <asp:ListBox ID="lbEvidence" 
        runat="server" 
        CssClass="form-control" 
        Height="250px" 
        Width="170px"
        DataTextField="name" 
        DataValueField="file"
        OnSelectedIndexChanged="Index_Changed"
        AutoPostBack="true">
    </asp:ListBox>
</div>

with this code behind

protected void Index_Changed(Object sender, EventArgs e)
{
    string text = "", value = "";
    ListBox x = sender as ListBox;
    if (x.ID == "lbRoot")
    {
        text = lbRoot.SelectedItem.Text;
        value = lbRoot.SelectedItem.Value;
    }
    else if (x.ID == "lbEvidence")
    {
        text = lbEvidence.SelectedItem.Text;
        value = lbEvidence.SelectedItem.Value;
    }


    //tried this for fixing the bug

    lbRoot.SelectedIndexChanged -= Index_Changed;
    lbRoot.SelectedIndex = -1;
    lbRoot.SelectedIndexChanged += Index_Changed;

    lbEvidence.SelectedIndexChanged -= Index_Changed;
    lbEvidence.SelectedIndex = -1;
    lbEvidence.SelectedIndexChanged += Index_Changed;

    doStuff(text, value);

}

 

Answer 1

User-1716253493 posted

protected void Index_Changed(Object sender, EventArgs e)
{
    string text = "", value = "";
    ListBox x = sender as ListBox;
    text = x.SelectedItem.Text;
    value = x.SelectedItem.Value;
    doStuff(text, value);
}

Answer 2

User-1716253493 posted

How you populate the ListBox Items?

Seem like when the ListBox indexchanged causing another ListBox indexchanged

For example changing category can cause subcategory selectedindexchanged event

Answer 3

User-902956371 posted

haha I like your modification here, but still the same problem. Click lb2 and lb1 is the one that is sent.

and yes, I tried with an event for each lb, and after clicking lb2, event of lb1 was triggered.

Answer 4

User-902956371 posted

Well.. I fixed my problem in a dirty way... 

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        Session["rootID"] = -1;
        Session["evidenceID"] = -1;
    }
}

 and in the event

protected void Index_Changed(Object sender, EventArgs e)
{
    string text = "", value = "";
    int r = int.Parse(Session["rootID"].ToString());
    int ev = int.Parse(Session["evidenceID"].ToString());

    if ( r != lbRoot.SelectedIndex)
    {
        Session["rootID"] = lbRoot.SelectedIndex;
        text = lbRoot.SelectedItem.Text;
        value = lbRoot.SelectedItem.Value;
    }
    else if (ev != lbEvidence.SelectedIndex)
    {
        Session["evidenceID"] = lbEvidence.SelectedIndex;
        text = lbEvidence.SelectedItem.Text;
        value = lbEvidence.SelectedItem.Value; ;
    }

    doStuff(text, value);
}

I tried ViewState instead of Session.... but for a weird reason, the ViewState was losing the values going back to -1...