Question Re: DropDown box in Windows Form

savoym · March 11th, 2004, 08:14 AM

In creating a dropdown box in a WINDOWS FORM, not a web form, that contains each month of the year I did the following:

//
// lstMonthText
//
this.lstMonthText.Items.AddRange(new object[] {
"January",
"February",
"March",
"April",
"May",
"June",
"July",
"August",
"September",
"October",
"November",
"December"});
this.lstMonthText.Location = new System.Drawing.Point(560, 40);
this.lstMonthText.Name = "lstMonthText";
this.lstMonthText.Size = new System.Drawing.Size(112, 17);
this.lstMonthText.TabIndex = 1;
this.lstMonthText.SelectedIndexChanged += new System.EventHandler(this.lstMonthText_SelectedInde xChanged);

However I am needing now to only list the CURRENT MONTH and the PREVIOUS MONTH in this dropdown list per the customer. In C#, does anyone have any code examples or direct me to a code example that could help me with this? Any help or direction would be appreciated.

Thanks.

KABay · March 11th, 2004, 05:24 PM

To load the list how about ...

Code:

DateTime dtMonth;

dtMonth = DateTime.Now;
this.lstMonthText.Items.Add(dtMonth.ToString("MMMM"));
this.lstMonthText.Items.Add(dtMonth.AddMonths(-1).ToString("MMMM"));
// Select 'this' month as the default 
this.lstMonthText.SelectedIndex = 0;

Then the list will always be current with this month and last month.

savoym · March 11th, 2004, 05:30 PM

KABay,

Thanks a lot. THAT GOT IT!!

Your help is appreciated!!

savoym · March 12th, 2004, 11:45 AM

Ran into a problem. I am needing to pass on the INT value of the month into my stored procedure from these two items listed in KABay's example below.

Is there not a way to assign the INT value associated with the month listed in my LISTBOX like you would in HTML?

Here is the code example:

//
// lstMonthText
//
DateTime dtMonth;
dtMonth = DateTime.Now;

// 3/10/2004 = Per customer, define only the current and previous months in the dropdown.
this.lstMonthText.Items.Add(dtMonth.AddMonths(-1).ToString("MMMM").);
this.lstMonthText.Items.Add(dtMonth.ToString("MMMM "));

//Select 'this' month as the default
this.lstMonthText.SelectedIndex = 0;
this.lstMonthText.Location = new System.Drawing.Point(560, 40);
this.lstMonthText.Name = "lstMonthText";
this.lstMonthText.Size = new System.Drawing.Size(112, 17);
this.lstMonthText.TabIndex = 1;
this.lstMonthText.SelectedIndexChanged += new System.EventHandler(this.lstMonthText_SelectedInde xChanged);

Thank you.

KABay · March 12th, 2004, 01:59 PM

Sorry this is a little long but it IS fully functional. Just cut and paste (replace) all the code in an empty/new C# Solution.

The key concept here is that you are defining a data source from which to extract the 'value' you are looking for for the month selected.

(This code was 'ripped' from the MSDN Library)

Code:

using System;
using System.Windows.Forms;
using System.Drawing;
using System.Collections;


namespace MyListControlSample
{

    public class MonthItem
    {
        private string myMonthNumber;
        private string myMonthName;

        public  MonthItem(string strMonthName, string strMonthNumber)
        {
            this.myMonthNumber = strMonthNumber;
            this.myMonthName = strMonthName;
        }

        public string MonthNumber
        {
            get
            {
                return myMonthNumber;
            }
        }

        public string MonthName
        {
            get
            {
                return myMonthName;
            }
        }

        public override string ToString()
        {
            return this.MonthName + " - " + this.MonthNumber;
        }
    }

    public class ListBoxWithValue:Form
    {
        private ListBox lstboxMonths = new ListBox();
        private TextBox txtMonthValue = new TextBox();

        [STAThread]
        static void Main() 
        {
            Application.Run(new ListBoxWithValue());
        }

        public ListBoxWithValue()
        {

            this.AutoScaleBaseSize = new Size(5, 13);
            this.ClientSize = new Size(292, 181);
            this.Text = "ListBox Sample3";

            lstboxMonths.Location = new Point(24, 16);
            lstboxMonths.Name = "lstboxMonths";
            lstboxMonths.Size = new Size(232, 130);

            txtMonthValue.Location = new Point(24, 160);
            txtMonthValue.Name = "txtMonthValue";
            txtMonthValue.Size = new Size(240, 24);
            this.Controls.AddRange(new Control[] {lstboxMonths, txtMonthValue});

            // ***************************************
            // Start the really significant stuff
            // ***************************************

            // Populates the list box using DataSource. 
            ArrayList MonthItems = new ArrayList();

            DateTime dtMonth;
            string sMonthName;
            string sMonthValue;

            dtMonth = DateTime.Now;

            sMonthName = dtMonth.ToString("MMMM");
            sMonthValue = dtMonth.ToString("MM");
            MonthItems.Add(new MonthItem(sMonthName, sMonthValue));

            dtMonth = dtMonth.AddMonths(-1);

            sMonthName = dtMonth.ToString("MMMM");
            sMonthValue = dtMonth.ToString("MM");
            MonthItems.Add(new MonthItem(sMonthName, sMonthValue));

            // ***************************************
            // End the really significant stuff
            // ***************************************

            lstboxMonths.SelectedValueChanged += new EventHandler(lstboxMonths_SelectedValueChanged);
            lstboxMonths.DataSource = MonthItems;
            lstboxMonths.DisplayMember = "MonthName";
            lstboxMonths.ValueMember = "MonthNumber";

        }
        private void InitializeComponent()
        {

        }

        private void lstboxMonths_SelectedValueChanged(object sender, EventArgs e)
        {
            if (lstboxMonths.SelectedIndex != -1)
                txtMonthValue.Text = lstboxMonths.SelectedValue.ToString();
        }
    }
}

savoym · March 15th, 2004, 09:10 AM

KABay,

thanks for taking the time to come up with this code. I will try it out this morning.

Again, your help and time are very much appreciated.