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.
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:
|
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.