Message object properties

Table 20-3 lists the properties of the Message object and the datatype and uses of each. The first four properties of the Message object correspond to the first four properties of the Microsoft Windows message structure.

Table 20-3: Message object properties

Property

Datatype

Use

Handle

Integer

The handle of the window or control.

Number

Integer

The number that identifies the event (this number comes from Windows).

WordParm

UnsignedInt

The word parameter for the event (this parameter comes from Windows). The parameter’s value and meaning are determined by the event.

LongParm

Long

The long parameter for the event (this number comes from Windows). The parameter’s value and meaning are determined by the event.

DoubleParm

Double

A numeric or numeric variable.

StringParm

String

A string or string variable.

PowerObjectParm

PowerObject

Any PocketBuilder object type, including structures.

Processed

Boolean

A boolean value set in the script for the user-defined event:

  • true – the script processed the event. Do not call the default window Proc (DefWindowProc) after the event has been processed.

  • false (default) – call DefWindowProc after the event has been processed.

ReturnValue

Long

The value you want returned to Windows when Message.Processed is true.

When Message.Processed is false, this attribute is ignored.

Use the values in the Message object in the event script that caused the Message object to be populated. For example, suppose the FileExists event contains the following script. OpenWithParm displays a response window that asks the user if it is OK to overwrite the file. The return value from FileExists determines whether the file is saved:

OpenWithParm( w_question, &
   "The specified file already exists. " + &
   "Do you want to overwrite it?" )
IF Message.StringParm = "Yes" THEN
   RETURN 0  // File is saved
ELSE
   RETURN -1 // Saving is canceled
END IF

When processing messages, Windows CE supports both system-defined messages and application-defined messages. Windows CE does not support hooking messages. For information on Microsoft message types, see the MSDN library.