Modifying a
DataWindow object
During execution, you can modify the appearance and behavior of a
DataWindow object by doing one of the following:
-
Changing the values of its properties
-
Adding or deleting controls from the DataWindow object
Changing property values
You can use the Modify method or a property expression to set
property values. This lets you change settings that you ordinarily specify
during development in the DataWindow painter.
Before changing a property, you might want to get the current value
and save it in a variable so that you can restore the original value
later. To obtain information about the current properties of a DataWindow
object or a control in a DataWindow object, use the Describe method or a
property expression.
Using expressions in property
values
With some DataWindow properties, you can assign a value through an
expression that the DataWindow evaluates during execution, instead of
having to assign a value directly. For example, the following statement
displays a salary in red if it is less than $12,000, and in black
otherwise:
|
1 2 |
dw_1.Modify("salary.Color & = '0 ~t if(salary <12000,255,0)' ") |
For more information
The syntax is different for expressions in code versus expressions
specified in the DataWindow painter. For the correct syntax and
information about which properties can be assigned expressions, see the
the section called “Using DataWindow expressions as property values” in DataWindow Reference.
For more information about property expressions and DataWindow
object properties and examples of using Describe and Modify methods, see
the the section called “PowerBuilder: Modify and Describe methods for properties” in DataWindow Reference.
Adding and deleting controls within the
DataWindow object
You can also use the Modify method to:
-
Create new objects in a DataWindow object
This lets you add DataWindow controls (such as text, bitmaps,
and graphic controls) dynamically to the DataWindow object.For how to get a good idea of the correct Create syntax, see
Specifying the DataWindow
object syntax. -
Destroy controls in a DataWindow object
This lets you dynamically remove controls you no longer
need.
PowerBuilder tool for easier coding of
DataWindow syntax
PowerBuilder only
Included with PowerBuilder is DW Syntax, a tool that makes it easy
to build the correct syntax for property expressions, Describe, Modify,
and SyntaxFromSQL statements. You click buttons to specify which
properties of a DataWindow you want to use, and DW Syntax automatically
builds the appropriate syntax, which you can copy and paste into your
application code.
See Using DWSyntax for more
information.
Viewing DataWindow object properties in
PowerBuilder
PowerBuilder only
You can use the PowerBuilder Browser to get a list of DataWindow
properties: on the DataWindow tab, select a DataWindow object in the left
pane and Properties in the right pane. To see the properties for a control
in a DataWindow object, double-click the DataWindow object name, then
select the control.