listbox sorting?

[vbMarkO]

I am loading Dates into a listbox....

 

At the moment I have dtPick.value which is 8/4/2006 12:39 AM

 

OK but what I want is Friday, August 04, 2006

 

The problem is I think is this is not as easy to keep in a sorted order

 

I am sure this has been asked before but cant find anything specific but will keep looking.

 

Anyway, Is there a way somehow to do a comparison beofer the date is added to the listbox so that it places it in the right order or is there a easier way to do it that I am just not aware of?

 

vbMarkO

[MrPaul]

To control formatting, I would wrap the date value in a custom object:

 

private class ListboxDateItem
{
   //Fields
   public readonly DateTime Date;

   //Constructors
   public ListboxDateItem(DateTime date)
   {
       Date = date;
   }

   //Methods
   public override string ToString()
   {
       return Date.ToString("dddd, MMMM MM, yyyy");
   }
}

 

Then when adding a date, I would suggest iterating through the collection until a later date is encountered, and insert the new date before that item:

 

private void AddDate(DateTime newdate)
{
   int index = 0;

   foreach (ListboxDateItem lbd in listBox1.Items) {
       if (lbd.Date > newdate) break;
       index++;
   }

   listBox1.Items.Insert(index, new ListboxDateItem(newdate));
}

 

Good luck :cool:

[MrPaul]

Playing for the other team...

 

Apologies, I forgot you are using Visual Basic. Here is a translation.

 

        Private Class ListboxDateItem
           'Fields
           Public ReadOnly [Date] As DateTime

           'Constructors
           Public Sub New(ByVal thedate As DateTime)
               [Date] = thedate
           End Sub

           'Methods
           Public Overrides Function ToString() As String
               Return [Date].ToString("dddd, MMMM MM, yyyy")
           End Function
       End Class

       Private Sub AddDate(ByVal newdate As DateTime)
           Dim index As Integer = 0

           For Each ldi As ListboxDateItem In Listbox1.Items
               If (ldi.Date > newdate) Then Exit For
               index = index + 1
           Next

           Listbox1.Items.Insert(index, New ListboxDateItem(newdate))
       End Sub

 

Good luck :cool:

[vbMarkO]

Forgive my ignorance but how would I execute this code from a button click event

 

my button is btnVisit

 

vbMarkO

[Cags]

On a button click you just have

' where DateTime.Now is the time you wish to add
AddDate(DateTime.Now)

[vbMarkO]

OK tried this and this is what I got

 

I put AddDate(DateTIme.Now) int he btnVisit_Click event

 

result was this; Unable to cast object of type 'System.String' to type 'ListboxDateItem'.

 

The dates being added to the listbox are from a DatePicker

 

User selects Date in dtPick <--- DatePicker

 

the btnVisit click event then adds the date that is in the dtPick.Text field

 

The dates added to lstDates are in this format Friday, August 04, 2006

 

What I am needing is to make sure the dates stay in a sorted order...

 

vbMarkO

[Cags]

Try using the Value property of the DateTimePicker, not the Text property.

[MrPaul]

This method will only work if every item in the listbox is an instance of ListboxDateItem. Judging by the exception you're seeing, I would guess that there are items in the listbox which have been inserted as strings.