How to retrieve value from ComboBox in C#

Question

Hi,
I have a problem to get value in C# but not in VB.net.

Case: I have loaded the data into ComboBox from SqlCe Data

Example :
cboCountry.DataSource = DS.Tables["tblCountry"];
cboCountry.DisplayMember = "Country";
cboCountry.ValueMember = "Cid";

To retrieve the value of the selected item from the combo box

In VB.net
...............

  Dim Idno As Integer = CboCountry.SelectedValue

This will give me the Value of the Id  which is the value member in CboCountry


in C#, I can not get any thiing??

string StrId = CboCountry.SelectedValue(); <--- this wont work!!!

How do I get the value and How can I covert this StrId into integer?


thanks

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Peace is the fruit of Love

Answer 1

Hi,

I would probably use a line as follows :-

this.label1.Text = this.comboBox1.Items[this.comboBox1.SelectedIndex].ToString();

This is demonstrated in the project ComboBox Selected Item Tester here :-

http://www.smartmobiledevice.co.uk/Projects

Hope this helps.

Paul Diston

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http://www.smartmobiledevice.co.uk/

Answer 2

Hi Paul,

It seems it wont work.

This is my form outlay :   

1)    CboCountry

2)    BtnSelect.

In BtnSelect , this is the code:

private void BtnSelect_Click(object sender, EventArgs e)

        {
            int cboIndex = cboCountry.SelectedIndex;          
            string strId = this.cboCountry.Items[cboIndex].ToString();

            MessageBox.Show("Select Id :" + strId);

            //ShowCity(StrId);
            
        }


I got error msg : "system.Data.DataRowView


My Objective:  If the user select a country in the cboCountry, I need to get the Id of the country so that I can pass it to the ShowCity(StrId)

How Do I get the Id ? Do I need to convert the result return from the cbo.items[] method??


Thanks

---

Peace is the fruit of Love

Answer 3

How did you populate your ComboBox?

Normally, I know how exactly what the ComboBox item collection contains and I use ComboBox.SelectedItem to retrieve it and cast it into the type I need.

Answer 4

Hi Christian Resma Helle,

This is the way I populate the combobox:

               SqlCeConnection cn;

                cn = new SqlCeConnection("Data Source=" + StrDbPath + "\\Cities.sdf;");

                cn.Open();

                SqlCeCommand cmd = null;
               cmd = cn.CreateCommand();              
                cmd.CommandText = "Select Cid,Country from tblCountry";

                SqlCeDataAdapter MyAdapter = new SqlCeDataAdapter(cmd);
                DataSet DS = new DataSet();
                MyAdapter.Fill(DS, "tblCountry");
                cn.Close();
              
                cboCountry.DataSource = DS.Tables["tblCountry"];
                cboCountry.DisplayMember = "Country";
                cboCountry.ValueMember = "Cid";

How do i get the Id  when user click and select in combobox.

Thank

---

Peace is the fruit of Love

Answer 5

DataRowView has a property called Row which returns the DataRow, from there you just retrieve the value from the column.

Example:

DataTable dataTable = new DataTable("Country");
dataTable.Columns.Add("Id");
dataTable.Columns.Add("Name");
dataTable.Rows.Add(45, "Denmark");
dataTable.Rows.Add(63, "Philippines");  
comboBox1.DataSource = dataTable;
comboBox1.DisplayMember = "Name";

comboBox1.SelectedIndex = 1;
comboBox1.Refresh();  

DataRow selectedDataRow = ((DataRowView)comboBox1.SelectedItem).Row;
int countryId = Convert.ToInt32(selectedDataRow["Id"]);
string countryName = selectedDataRow["Name"].ToString();

Answer 6

SelectedValue normally works, but doesn't always give you the type it should. In the code below, even though I entered Country.Id as an integer, SelectedValue returns a string.

Example:

DataTable dataTable = new DataTable("Country");
dataTable.Columns.Add("Id");
dataTable.Columns.Add("Name");
dataTable.Rows.Add(45, "Denmark");
dataTable.Rows.Add(63, "Philippines");

comboBox1.DataSource = dataTable;
comboBox1.DisplayMember = "Name";
comboBox1.ValueMember = "Id";

comboBox1.SelectedIndex = 1;
comboBox1.Refresh();

DataRow selectedDataRow = ((DataRowView)comboBox1.SelectedItem).Row;
int countryId = Convert.ToInt32(selectedDataRow["Id"]);
string countryName = selectedDataRow["Name"].ToString();

int selectedValue = Convert.ToInt32(comboBox1.SelectedValue);

Answer 7

hi Christian Resma Helle

Thank you very much. This problem is solved. This method provide great interactivity.

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Peace is the fruit of Love