Amund

Amund

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refering to the right combobox at runtime

Nov 22 2010 4:21 AM
Hi,

I'm having difficulties populating the right combobox when I generate several combobox' at runtime. I've got a windows forms application, where the form consists of a button and a FlowLayoutPanel. By clicking the button, a control combination consisting of a label and two combobox' are added to the Form (to the FlowLayoutPanel). The code so far is given below:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public int counter;
        public ComboBox combB;
        public string[] combValuesShip;
        public string[] combValuesCar;
        public string[] combValuesAirPlane;
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            AddNewComboboxLine();
        }

        private void AddNewComboboxLine()
        {
            counter++;
            Label label = new Label();
            label.Text = "Label " + counter;
            ComboBox combA = new ComboBox();
            string[] combAValues = new string[] { "Ship", "Car", "AirPlane" };
            combA.Items.AddRange(combAValues);
            combB = new ComboBox();
            combA.SelectedIndexChanged += new EventHandler(this.combAChange);

            label.Name = "label" + counter.ToString();
            combA.Name = "combA" + counter.ToString();
            combB.Name = "combB" + counter.ToString();

            flowLayoutPanel1.Controls.Add(label);
            flowLayoutPanel1.Controls.Add(combA);
            flowLayoutPanel1.Controls.Add(combB);

            combValuesShip = new string[] { "Ferry", "OilTanker", "ContainerVessel" };
            combValuesCar = new string[] { "Toyota", "Lada", "Ferrari" };
            combValuesAirPlane = new string[] { "Boeing", "Airbus", "Sailplane" };

        }

        private void combAChange(object sender, EventArgs e)
        {
            MessageBox.Show(((ComboBox)sender).Name);    
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

    }
}

the first combobox in each control combination (combA) is populated with "Ship", "Car", "AirPlane". So far so good. The problem is getting combobox combB to be populated with respective values. I can always add something like this under the eventhandler for combobox combA:

 private void combAChange(object sender, EventArgs e)
        {
            ComboBox currentCombobox = (ComboBox)sender;
            string lastChar = currentCombobox.Name.Substring(currentCombobox.Name.Length - 1, 1);
            if (lastChar == "1")
            {
                combB.Items.Clear();
                combB.Items.AddRange(combValuesShip);
            }

            if (lastChar == "2")
            {
                combB.Items.Clear();
                combB.Items.AddRange(combValuesCar);
            }

            if (lastChar == "3")
            {
                combB.Items.Clear();
                combB.Items.AddRange(combValuesAirPlane);
            }

        }

This works fine if i add one control combination at a time and select the values in the combobox' before adding new. However, editing a previous added combobox is now not possible. I.e. if i have added three lines (each with a label and two combobox'), but now want to change values in the first line, this is not possible.

Any suggestinons would be highly appreciated

-Amund

Answers (3)