Custom ListBox with columns

CodeGuru content and product recommendations are editorially independent. We may make money when you click on links to our partners. Learn More.

Download Source Code and Example

This article describes a custom a list box with columns. I will explain how
the program works, but for a better understanding you should read the source
code. This source is part of a big project that has to do with pizzas and
that’s why it contains the pizza word in several places.

1. In the OnInitDialog() function I am initializing the ClientsLB,
   which is of type CDBListBox. I am getting the positions of some
   dialog controls and I am using this information to position my
   list box at the correct place. The actual initialization of the
   ClientsLB is done by calling:

   
   
      ClientsLB.Init( 20, tmpRect2, this, IDC_CLIENTLB );
   
   

   The first parameter is the height of the list box items
   The second its position
   The third the parent window
   The last is the controls id

   Then I am adding tab stops to the control, meaning that I am
   telling the control where to put each column. This is done by calling

   
   
      SetTabStop( short ColumnIndex, short ColumnPosition )
   
   

   In this application I am using the position of the edit controls
   above my list box in order to set the tabs position.

2. The control is now ready to accept data. This is done by calling the
   CListBox::AddString() but the string must have a special format. It
   contains all the columns seperated by #. For example:

   
   
      AddString( “column1#column2#column3” )
   
   

   The control will extract every column and will display it at the
   appropriate position, as given by SetTabStop().

   The control has a function called GetCurrentID(). This function
   returns the first column of the selected item as a CString, it is
   assumed that this is an id column. If there is no current selection
   in the list box, it returns “NS”.

   It also has a function called ExtractString(). You must call this
   function twice. The first time with CMD_RESET as the first parameter
   and a string to analyze as the second. The string is copied to the
   internall buffer and then by calling the function again with CMD_NEXT
   as the first parameter we are getting the extracted CString in the
   second. Every time called it returns the next column of the
   given string. The function returns the index of the extracted column
   or -1 if there is not another column in the given string.

   So by using the AddString we are adding data to the listbox and
   by using GetText we are getting a string from it. By calling ExtractString
   we are getting the columns of the above string.

3. The list box is connected to the edit controls above it. This is done
   by handling the ON_LBN_SELCHANGE() event. You can read the
   CPizzaDlg::OnSelchange() in order to understand how we can use
   ExtractString().

   You can read the CPizzaDlg::OnAddNew() in order to see how we can
   format the strings we add to the list box.

4. I am using the AddNew() and Update() to add a record to my database
   I am using SQL commands to delete, modify and find records. I am using
   CDaoRecordset because when I used CRecordset I found that there was
   a problem when I used LIKE ‘*’ in my SQL question. CDatabase was
   searching for the * in my database, didn’t used it as a balanter.

5. CPizzaDlg::PopulateLB() is an example of how you can populate the
   list box with database records.

6. The sample application is a simple addresser. To find a record you
   give an id or any other information ( SurName, SecondName, … ), you
   can give only the first letters. If you give the id the other fields
   are ignored. Then press find. When pressing the Add Button, you are
   adding a record, and Delete deletes it. You can also modify the
   selected record. If you want to see all the records just leave the
   edit boxes empty and press the find button.

   Last updated: 4 July 1998