Overview of the ActiveX Access Method

Overview of the ActiveX Access Method

The ActiveX access method is a set of nine custom controls that enable development environments that support ActiveX to easily access Btrieve data. The interface includes a data source control and eight bound data controls.

The PSQL data source control provides the connection point between your application and a Btrieve data file. In addition to acting as a data source for other data-aware controls, the data control also exposes properties, methods, and events you can use to access data from code in your application—opening, closing, and creating files; and retrieving, updating and deleting records.

The PSQL bound controls, which must be attached to the data source control, include data-aware text box, list box, combo box, check box and option button controls. The list and combo box controls operate either as field-bound controls or as multi-column record list controls. Command button and horizontal and vertical scroll bar controls provide indexed record navigation.

In Microsoft Visual Basic, the PSQL data source control can also act as a record source for data-aware Visual Basic controls, and for third-party data-aware ActiveX controls.

This section features the following subsections:

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Development Environments

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Third-Party Data Bound Controls

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ActiveX Control Objects

Development Environments

The ActiveX access method supports the following environments:

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Visual Basic 5.0 and higher

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Delphi 3.0 and higher

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Visual C++ 5.0 and higher

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Embarcadero C++ Builder 3.0 and higher

Note: Several other development environments and applications also provide support for ActiveX control extensions. However, Actian Corporation has not tested its ActiveX access method in any programming environments, languages, or applications not specifically listed above.

Third-Party Data Bound Controls

The ActiveX access method can bind data from Sheridan, APEX, GreenTree, and Microsoft Controls. Actian Corporation only recommends using these third-party products when they have formatting or presentation functionality not present in the ActiveX access method.

Because Actian Corporation cannot control the development of third-party software, it does not support all of the functionality of these controls. For the same reason, it cannot offer technical support on these products.

Note: Data binding to third-party data-aware controls is not supported in any environment other than Microsoft Visual Basic.

ActiveX Control Objects

The ActiveX control objects included with the ActiveX access method are listed in the following table:

Table 1

Included ActiveX Control Objects

The data source control provides your application source code and PSQL Bound Controls access to a data file.

Check box can be bound to boolean (True/False) type fields.

Data-bound combo box can be bound to one field in a record, allowing the user to select a value for the field from a predetermined set of values. It can also serve as a record list control, or as a list of available index fields.

VACommandButton

Data-bound command button can execute record retrieval, update, or delete operations.

VAHScrollBar

VAVScrollBar

Data-bound scroll bars allow the user to scan through records along an index path.

The list box control allows the user to select a field value from a predetermined set of values. It can also serve as a multi-column record list control.

The option button may be bound to a boolean (True/False) type field.

The data-aware text box can automatically display and permit modification of any field. It also can be used in search mode to seek matching records from a file as text is entered.