Listbox with hidden id

[viana]

Hi, i need to create a listbox from a database, which should display the name of a field and have the row id hidden, that i can "see" to manipulate the database table.

[James T Johnson]

There are a few ways of going about this, one is with a DataSet/DataTable the other is using a custom class. With a DataSet:

Set the listbox's DisplayMember and ValueMember properties to the name of the fields in the DataTable (if using a DataSet prefix them with the name of the table), then set the DataSource property to the instance of the DataSet or DataTable.

With a custom class: First define your custom class

public class MyData
{
private int id;
public string theField;
// More data members

public MyData(int id, string theField)
{
this.id = id;
this.theField = theField;
}
// More Constructors

public int ID
{
get { return id; }
}

public string TheField
{
get { return theField; }
set { theField = value; }
}
}

Now on the ListBox, set the ValueMember to "ID" and the DisplayMember to "TheField". Once you have a collection of MyData objects (an Array or ArrayList or something that implements IList which returns instances of MyData) assign that collection to the DataSource property of the ListBox.

MyData [] data = new MyData[3];
data[0] = new MyData(0, "Huey");
data[1] = new MyData(1, "Dewy");
data[2] = new MyData(2, "Louie");

myListBox.DisplayMember = "TheField";
myListBox.ValueMember = "ID";
myListBox.DataSource = data;

HTH, James "It is self repeating, of unknown pattern" Data - Star Trek: The Next Generation

[viana]

hi, if i understand this rigth in a listbox i can have a field to be displayed and a value "linked" to that field. what i did was: public class BaseDados { public DataTable doquery(string query) { OleDbDataAdapter DataAdapter = new OleDbDataAdapter(query, connectionString); DataSet dataSet = new DataSet(); DataAdapter.Fill(dataSet, "Same"); DataTable dataTable = dataSet.Tables[0]; return dataTable; } } and in the class of the form where is my listbox i put: BaseDados db = new BaseDados(); DataTable table = db.doquery("Select * from autenticacao"); listBoxOrigem.DisplayMember = "email"; listBoxOrigem.ValueMember = "id"; listBoxOrigem.DataSource = table;

[James T Johnson]

viana wrote: if i understand this rigth in a listbox i can have a field to be displayed and a value "linked" to that field. I think you got it :) James "It is self repeating, of unknown pattern" Data - Star Trek: The Next Generation

[viana]

hi, if i understand this rigth in a listbox i can have a field to be displayed and a value "linked" to that field. what i did was: public class BaseDados { public DataTable doquery(string query) { OleDbDataAdapter DataAdapter = new OleDbDataAdapter(query, connectionString); DataSet dataSet = new DataSet(); DataAdapter.Fill(dataSet, "Same"); DataTable dataTable = dataSet.Tables[0]; return dataTable; } } and in the class of the form where is my listbox i put: BaseDados db = new BaseDados(); DataTable table = db.doquery("Select * from autenticacao"); listBoxOrigem.DisplayMember = "email"; listBoxOrigem.ValueMember = "id"; listBoxOrigem.DataSource = table; and it display the field email correctly. How can i read the selected item from my listbox, the id i tried: string b=listBoxOrigem.SelectedItem.ToString(); but it did't work

[James T Johnson]

I thought it was odd you'd put all of that in a reply just to say you have it right :) viana wrote: How can i read the selected item from my listbox, the id string b = listBoxOrigem.Selected**Value**.ToString(); James "It is self repeating, of unknown pattern" Data - Star Trek: The Next Generation