Connecting controls

The chapter Getting started told you how to set up blueshell Active Tables to let the user edit a table thru a grid view. In a grid view each record of the table is shown as a row of the grid. Each column of the grid belongs to a field of the table. bAt supports an additional mode: Form view. In form view a single record of the table is shown on the form. There are some controls on the form and each control can be bound to a field of the table. Unlike in grid view there can be additional unbound controls, supporting additional information or controlling options like command buttons do.

Binding controls to a data source can also be done in traditional VB programming. There are even wizards that are doing parts of the designer's work for you. If you want to design a framework that supports a grid view and a form view a complex and fragile structure has to be set up:

• You need a data source that hosts the table (like the adodc control)
• You need something like command buttons for insert, store, delete, refresh (and possibly sort and filter) with underlying code
• You need the controls bound to the data source
• You need a grid control bound to the data source
• You need to synchronize the grid and the controls
• You need something that switches between the controls and the grid (like a TabStrip control)

Using bAt live is easier:

• You need an atb control that hosts the table
• You need to put controls for the fields on the atb control in order to support form view

How to do

• Draw a blueshell txt control on the atb control.
• Set the Name of the txt control to a name of a column in the atb control. This already connects the txt control to the atb control. To indicate this, the background of the txt's caption is marked yellow (of course only in design view).

There are several alternatives to connect the txt control to an atb control:

• If the txt control is a child control of the atb control (i.e. it is drawn onto the atb control):
  • Set txt.Name to the name of the column
    or
  • Set txt.DataField to the name of the column
• Else:
  • Set txt.Name to the name of the column and set txt.DataMember to the the name of the atb control
    or
  • Set txt.DataField to the name of the column and set txt.DataMember to the the name of the atb control

  
  We recommend that you're using the Bindings property page to access the DataMember/DataField (and ListDataMember, BoundColumn and ListField when using the cbo control) properties.

Other blueshell controls

chk and cbo controls are working as described above for txt controls.

Other controls

You may implement an IBatControl interface to bind other controls.

Using the bAt Master

Often it is necessary to add a lot of controls to an atb control. As outlined above bAt makes it easy to bind controls, but if you perhaps have to bind 20 or more of them it may be still cumbersome to add and bind them, to provide captions and to position properly. The bAt Master Add-In can help you doing this. Just give it a try!