Auto remember on DropDownList fields using Session. - asp.net

Question

I want to implement "auto remember" feature of a form. This app is used by accountants who track cheque payments.
The accountant is entering a number of checks at a time and it will be time saving to maintain the project, beneficiary and project instead of choosing them every time you want to add a transaction.
The form looks like attached.
So far my attempts are failing and i keep seeing the dash entry '-' always at the top of each of the three dropdownfields as if i did nothing.
However 'watch' paramters shows that the Session values are properly retrieved and set.
I'm trying to save the previously entered values of those fields in a Session. Unless someone has another thought.
The nature of the fields in the asp file is as such
<asp:DropDownList ID="ddAccount" runat="server" Height="24px" OnSelectedIndexChanged="ddAccount_SelectedIndexChanged" >
<asp:ListItem>-</asp:ListItem>
</asp:DropDownList>
*<br />
<br />
<asp:DropDownList ID="ddProject" runat="server" Height="22px" >
<asp:ListItem>-</asp:ListItem>
</asp:DropDownList>
*<br />
<br />
<asp:DropDownList ID="ddBenificiary" runat="server" >
<asp:ListItem>-</asp:ListItem>
</asp:DropDownList>
*<br />
<br />
On Page_load I added the following Session getters and setters. I choose to populate first, i.e get the accounts, projects
etc then set the proper value based on the sessions.
protected void Page_Load(object sender, EventArgs e)
{
try
{
user = (User)Session["user"];
if (!IsPostBack)
{
if (Session["IsValidUser"] == null || Session["IsValidUser"].ToString() != "true")
Response.Redirect("Login.aspx", false);
/// Setting the Body tag.
Site1 m = (Site1)Master;
m.PageSection = "transactions";
//////////////////////////
Populate();
if (Session["BankAccount_ATx"] == null)
{
Session.Add("BankAccount_ATx", null);
}
else ddAccount.DataTextField = Session["BankAccount_ATx"].ToString();
if (Session["Project_ATx"] == null)
{
Session.Add("Project_ATx", null);
}
else ddProject.DataTextField = Session["Project_ATx"].ToString();
if (Session["BenefClient_ATx"] == null)
Session.Add("BenefClient_ATx", null);
else
ddBenificiary.DataTextField = Session["BenefClient_ATx"].ToString();
}
}
catch (Exception ex)
{
Response.Redirect("Login.aspx");
}
}
I save the chosen value in the session on the save button.
Session["BankAccount_ATx"] = ddAccount.SelectedValue;
Session["Project_ATx"] = ddProject.SelectedValue;
Session["BenefClient_ATx"] = ddBenificiary.SelectedValue;
Many thanks guys and gals

Answer 1

You want to set the selected value of the dropdownlist, like this:
if (Session["Project_ATx"] == null)
{
Session.Add("Project_ATx", null);
}
else {
// Find the list item in the drop down that mataches the value in your session
ListItem li = ddProject.Items.FindByValue(Session["Project_ATx"]);
//Check to see if the list item was found in the drop down
//If it's found, then make it the selected item
if ( li != null )
li.Selected = true;
}
If you were storing the Text value in Session then use this method instead:
FindByText

Answer 2

If you store your value using:
Me.Session.Item("LastDdlValue") = Me.YourDdlValue.SelectedValue
You can use this code in Page_Load event when Not Me.Page.IsPostBack:
If Not IsNothing(Me.Session.Item("LastDdlValue")) Then
Me.YourDdlValue.SelectedValue = Me.Session.Item("LastDdlValue")
End If
Please note that you need to populate your DropDownList before setting its .SelectedValue.

Answer 3

FindByText is the best method, alternatively you can iterate through the items in the dropdown using for loop compare each item with the value saved in session. If they are equal set selected index
for(int i=0;i<dropdownlist1.Items.count;i++)
{
if(dropdownlist1.Items[i].Text==Session["Project_ATx"].ToString())//use dropdownlist1.Items[i].Value if you have stored the dropdownlist item value instead of text
{
dropdownlist1.SelectedIndex=i;
break;
}
}