Few months ago I encounter a problem with my windows form bound using a DataSet. When I open the form the first time, it seems that everything is fine. But when I open it again the second time, the fields are become blank. This happens when you trigger the “PerformClick” of “BindingNavigator” under the Form Load event.

This is not actually the common mistake that I encounter. But maybe, you encounter this problem also if you are used with VB 6.0 before.

Here’s the code to open the windows form the correct way:

After browsing several forum sites I found so many programmers having problem with ComboBox after they bind it to a DataSet.

The problem actually is not cause by a bug or the like. The error is caused by design. Here’s the following question on the internet that I found that will explain this error further:

http://thedailyreviewer.com/dotnet/view/data-bound-combobox-does-not-leave-focus-106127786

In our previous tutorial I discuss on “How to Create Master/Detail Windows Forms” on our Library System Project.

Today we will add MDI Form and create a main menu to open the forms on our project. If you follow closely this tutorial you will have now several Windows Forms on your project.

Please follow the steps below to Add MDI Form and Main Menu on your Library System project.

If you are using SelectedIndexChanged in your ComboBox may be you encounter a problem with events being fired even if you did not click the ComboBox.

This happens when you open and close your Windows Form. The workaround for this is to use RemoveHandler statement.

Here’s an example:

On my last tutorial I discuss on “How to Display Data in Windows Forms”. This time I will teach you on “How to Create Master/Detail Windows Forms”.

Creating a master/detail form still requires the same method as displaying data in windows forms. Except that we use additional control called “DataGridView”. This control will display the related record known as child form.