GroupBox

here is a small code excerpt used to get the text of the selected radio button

of a group:

var

        I: Integer;

        T: String;

begin

for I:=0 to GroupBox1.ControlCount -1 do

if (GroupBox1.Controls[I] as

        TRadioButton).checked then

        T := (GroupBox1.Controls[I] as 

        TRadioButton).Caption;

        ...

        ...

        ..

ComboBox Component

code below will trap the ENTER key and add the current Text to the list

if it's not found there (the list can not be empty):

procedure TForm1.ComboBox1KeyPress(Sender: TObject; var Key: char);

begin

// if the user press the

// Enter key

if Key = chr(13) then

        with ComboBox3 do

        if (Text <> '') and 

        (Items.IndexOf(Text) < 0)

        then

        Items.add(Text);

end;

Note:

first two(2) properties determine the main connection, as usual.

The other three(3) properties determine the secondary source(ListSource),

the field used for the join(KeyField), and the information to display(ListField).

RadioGroup Components

using the radio group is generally easier than using the group box, since the various items are part of a list, as in a list box. This is how you can get the text of the selected item:

Text := RadioGroup1.Items

        [RadioGroup1.ItemIndex];

ListBox Component

The selection of an item in a list box uses the Items and ItemIndex properties as in the code shown above for the RadioGroup control.

Result := List.Items [List.ItemIndex];

for a multiple-selection list box, see the code below:

var

        selItems: string;

        nItem: Integer;

begin

selItems := '';

for nItem := 0 to ListBox1.Items.Count-1 do

    if ListBox1.selected [nItem] then

        selItems := selItems +

        ListBox1.Items[nItem] + '';

        ...

        ..

DBLookupComboBox

If the list of values is extracted from another dataset, then you should use the specific DBLookupListBox or DBLookupComboBox components.

Here is a list of the relevant values:

DataField = 'cust_no'

DataSource = DataSourceOrders

KeyField = 'Cust_no'

ListField = 'company, cust_no'

ListSOurce = DataSourceCustomer

DropDownWidth = 30