listBox selected item

Question

I have three listBoxes:

listBox1 have the following items: Fruit and vegetable.

listBox2 have the following items: Orange, Apple, cucumber and Tomato.

li

Answer 1

You can try something like this, for easy understanding divide the functionality into functions. I designed this code using win forms however you can apply same code on List boxes as well.

    private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
    {
        switch(comboBox1.SelectedItem.ToString())
        {
            case "Fruit":
                FruitSelected();
                break;
            case "Vegetables":
                VegetableSelected();
                break;
            default:
                NoneSelected();
                break;
        }
    }
    private void comboBox2_SelectedIndexChanged(object sender, EventArgs e)
    {
        // Similar code as above
    }
    protected void FruitSelected()
    {
        comboBox2.Items.Clear();
        comboBox2.Items.Add("Orange");
        comboBox2.Items.Add("Apple");
    }
    protected void VegetableSelected()
    {
        comboBox2.Items.Clear();
        comboBox2.Items.Add("Tomato");
        comboBox2.Items.Add("Cucumber");
    }
    protected void NoneSelected()
    {
        comboBox2.Items.Clear();
        comboBox3.Items.Clear();
    }
}

Hope it helps.

Answer 2

you can try

listBox1_SelectedIndexChanged(obj ... , sender e)
{
     if(listBox1.SelectedItem.ToString() == "Fruit")
     {
        listBox2.Items.Add("Orange");
        listBox2.Items.Add("Apple");
      }
     else if()
     {
        // other conditons
      }
}

listBox2_SelectedIndexChanged(obj ... , sender e)
{
     if(listBox2.SelectedItem.ToString() == "Apple")
     {
        listBox3.Items.Add("Red");
        listBox3.Items.Add("Green ");
      ........
      }
     else if()
     {
        // other conditons
      }
}

read http://msdn.microsoft.com/en-us/library/system.windows.forms.listbox.selectedindexchanged.aspx

Answer 3

You would need to define the OnSelectionChanged Event of the comboBoxes.