Programmatically Binding DataSource To ComboBox In Multiple Ways

class Person {  
    public string Name {  
        get;  
        set;  
    }  
    public int Rank {  
        get;  
        set;  
    }  
    public string Gender {  
        get;  
        set;  
    }  
    public Person(int r, string n, string g) {  
        Rank = r;  
        Name = n;  
        Gender = g;  
    }  
}  
private void btn_FillWithArray_Click(object sender, EventArgs e) {  
    try {  
        Person[] list = new Person[] {  
            new Person(1, "Jon", "M"),  
                new Person(2, "Ram", "M"),  
                new Person(3, "Rin", "F"),  
                new Person(4, "Sue", "F"),  
                new Person(5, "Ken", "M"),  
                new Person(6, "Tom", "M"),  
                new Person(7, "Sam", "M")  
        };  
        comBox_FilledWithArray.DataSource = list;  
        comBox_FilledWithArray.DisplayMember = "Name";  
        comBox_FilledWithArray.ValueMember = "Gender";  
    } catch (Exception exc) {  
        MessageBox.Show(exc.Message);  
    }  
}  
private void comBox_FilledWithArray_SelectionChangeCommitted(object sender, EventArgs e) {  
    lbl_ArrayValue.Text = "Gender: " + comBox_FilledWithArray.SelectedValue.ToString();  
}

private void btn_FillWithList_Click(object sender, EventArgs e) {  
    try {  
        List < Person > list = new List < Person > () {  
            new Person(1, "Jon", "M"),  
                new Person(2, "Ram", "M"),  
                new Person(3, "Rin", "F"),  
                new Person(4, "Sue", "F"),  
                new Person(5, "Ken", "M"),  
                new Person(6, "Tom", "M"),  
                new Person(7, "Sam", "M")  
        };  
        comBox_FilledWithList.DataSource = list;  
        comBox_FilledWithList.DisplayMember = "Rank";  
        comBox_FilledWithList.ValueMember = "Name";  
    } catch (Exception exc) {  
        MessageBox.Show(exc.Message);  
    }  
}  
private void comBox_FilledWithList_SelectionChangeCommitted(object sender, EventArgs e) {  
    lbl_ListValue.Text = "Name: " + comBox_FilledWithList.SelectedValue.ToString();  
}

STORED PROCEDURE

CREATE PROCEDURE [dbo].[usp_GetAllAddresses]   
AS  
BEGIN  
SELECT [P_Id] as ID  
,[LastName] as LastName  
,[FirstName] as FirstName  
,[Address] as Address  
,[City] as City  
FROM [ADDRESS]  
END

CODE

private void btn_FillWithDataSet_Click(object sender, EventArgs e) {  
    try {  
        DataSet dsDataFromDB = GetDataFromDatabaseinDataSet();  
        comBox_FilledWithDataSet.DataSource = dsDataFromDB.Tables[0];  
        comBox_FilledWithDataSet.DisplayMember = "FirstName";  
        comBox_FilledWithDataSet.ValueMember = "City";  
    } catch (Exception exc) {  
        MessageBox.Show(exc.Message);  
    }  
}  
private void comBox_FilledWithDataSet_SelectionChangeCommitted(object sender, EventArgs e) {  
    lbl_DataSetValue.Text = "City Name: " + comBox_FilledWithDataSet.SelectedValue.ToString();  
}  
public DataSet GetDataFromDatabaseinDataSet() {  
    DataSet ds = new DataSet();  
    try {  
        // database Connection String  
        string connectionString = "Server = .; database = HKS; Integrated Security = true";  
        using(SqlConnection sqlCon = new System.Data.SqlClient.SqlConnection(connectionString)) {  
            using(SqlDataAdapter SqlDa = new SqlDataAdapter("usp_GetAllAddresses", sqlCon)) {  
                SqlDa.SelectCommand.CommandType = CommandType.StoredProcedure;  
                SqlDa.Fill(ds);  
            }  
        }  
        return ds;  
    } catch (Exception) {  
        throw;  
    }  
}

Binding with DataTable

Here we are getting data from a database in a DataTable instead of a DataSet (as in the previous section) and bind it to a Combo Box.

private void btn_FillWithDataTable_Click(object sender, EventArgs e) {  
    try {  
        DataTable dtDataFromDB = GetDataFromDatabaseinDataTable();  
        comBox_FilledWithDataTable.DataSource = dtDataFromDB;  
        comBox_FilledWithDataTable.DisplayMember = "ID";  
        comBox_FilledWithDataTable.ValueMember = "FirstName";  
    } catch (Exception exc) {  
        MessageBox.Show(exc.Message);  
    }  
}  
private void comBox_FilledWithDataTable_SelectionChangeCommitted(object sender, EventArgs e) {  
    lbl_DataTableValue.Text = "First Name: " + comBox_FilledWithDataTable.SelectedValue.ToString();  
}  
public DataTable GetDataFromDatabaseinDataTable() {  
    DataTable dt = new DataTable();  
    try {  
        // database Connection String  
        string connectionString = "Server = .; database = HKS; Integrated Security = true";  
        using(SqlConnection sqlCon = new System.Data.SqlClient.SqlConnection(connectionString)) {  
            using(SqlDataAdapter SqlDa = new SqlDataAdapter("usp_GetAllAddresses", sqlCon)) {  
                SqlDa.SelectCommand.CommandType = CommandType.StoredProcedure;  
                SqlDa.Fill(dt);  
            }  
        }  
        return dt;  
    } catch (Exception) {  
        throw;  
    }  
}

Binding with DataView

DataView in .Net also implements the IList interface, so it can be bound to a ComboBox's DataSource too. DataView is generally used to get a collection in a desired view after filtering out some rows from a DataTable. In the following code, we got the data from the database in a DataTable and after that we filtered out some rows ( ID > 5 ) and saved the required filtered data into a DataView.

private void btn_FillWithDataView_Click(object sender, EventArgs e) {  
    try {  
        DataTable dtDataFromDB = GetDataFromDatabaseinDataTable();  
        // Filtering rows with DataView class  
        DataView dv = new DataView(dtDataFromDB);  
        dv.RowFilter = "ID < 5";  
        comBox_FilledWithDataView.DataSource = dv;  
        comBox_FilledWithDataView.DisplayMember = "ID";  
        comBox_FilledWithDataView.ValueMember = "FirstName";  
    } catch (Exception exc) {  
        MessageBox.Show(exc.Message);  
    }  
}  
private void comBox_FilledWithDataView_SelectionChangeCommitted(object sender, EventArgs e) {  
    lbl_DataViewValue.Text = "First Name: " + comBox_FilledWithDataView.SelectedValue.ToString();  
}

Binding with Enumeration

We could bind any ComboBox to a list of an enumeration values easily by using its GetValues() method. Actually the GetValues() method of Enum returns an array of objects (as we know, that implements the IList interface). We can use this method to convert an enum to an array and bind to a ComboBox.

enum Weekdays {  
    Sunday,  
    Monday,  
    Tuesday,  
    Wednesday,  
    Thursday,  
    Friday,  
    Saturday,  
};  
private void btn_FillWithEnumeration_Click(object sender, EventArgs e) {  
    comBox_FilledWithEnumeration.DataSource = Enum.GetValues(typeof(Weekdays));  
}  
private void comBox_FilledWithEnumeration_SelectionChangeCommitted(object sender, EventArgs e) {  
    lbl_EnumerationValue.Text = "Selected day is: " + comBox_FilledWithEnumeration.SelectedValue.ToString();  
}

Summary

So here we learned how to bind a ComboBox DataSource to any Array of objects, List of Objects, DataTable, DataSet, DataView and Enumeration Values.