How to Get the selected Item id in list box using Linq Query

Question

var names = from s in dbc.Patient_Detail_Tables where s.Name.Contains(txtSearch.Text) select s;

listBox1.DataSource = names;

listBox1.DisplayMember = "Name";

listBox1.ValueMember = "RegitrationNo";

How to get the valuemember using Linq query?

Vulpes · Answer

You need to make sure the value is not null before applying ToString() to it: string s = ; // default value say if SelectedValue is null if (listBox1.SelectedValue != null) { s = listBox1.SelectedValue.ToString(); }

Sachin Kalia · Answer

Hi This is the code segment which can help you out somewhere : div > asp : ListBox ID =ListBox1 runat =server SelectionMode =Multiple> asp : ListItem Value =One Selected =True /> asp : ListItem Value =Two /> asp : ListItem Value =Three /> asp : ListItem Value =Four Selected =True /> asp : ListItem Value =Five /> asp : ListBox > br /> br /> asp : Button ID =btnSel runat =server Text =Get Selected onclick =btnSel_Click /> div > C# protected void btnSel_Click( object sender EventArgs e) { var selItems = from ListItem li in ListBox1.Items where li.Selected == true select li.Text; Response.Write( Selected Item(s):  ); foreach ( var item in selItems) { Response.Write(item.ToString() +   ); } } You can also refer this link : http://www.devcurry.com/2009/07/retrieve-selected-items-of-aspnet.html Cheers DotNet :)

paddu v · Answer

My Doubt is listbox1.ValueMember=RegitrationNo How to get this value for a variable like ..i given like this var s=listbox1.SelectedValue.ToString()but i am getting exception with Null

Vulpes · Answer

Assuming that RegistrationNo is a property of whatever class 's' belongs to then  if you change the first line to this then it should work: var names = (from s in dbc.Patient_Detail_Tables where s.Name.Contains(txtSearch.Text) select s).ToList();