Properties

About this topic

This topic describes the following properties:

•

Blocking

•	ControlPicture

Blocking

VARIANT_BOOL Blocking

Description

Determines whether methods should block until completion or return immediately for asynchronous operation.

Acceptable values

•	VARIANT_TRUE (C++) or True (Visual Basic .NET). The ActiveX control is forced to block or wait until a method completes before it returns control to the caller.

•	VARIANT_FALSE (C++) or False (Visual Basic .NET). Returns control to the application immediately, and the caller should handle the events accordingly.

Default value

VARIANT_FALSE (C++) or False (Visual Basic .NET)

Blocking affects some methods differently. See each method’s description for the effect. Unless otherwise noted:

•	In non-blocking mode (Block = VARIANT_FALSE or False), a method:

–	Starts another thread of execution to perform the given method, returning control to the application immediately.

–	Returns 0 on launching a new thread successfully; otherwise, returns nonzero, and an Error event is fired.

–	If the method is successful, an event indicating completion is fired; if unsuccessful, an Error event is fired.

•	In blocking mode (Block = VARIANT_TRUE or True), a method:

–	Is executed.

–	Returns 0 if it completes successfully; returns nonzero otherwise.

•	Error message can be reviewed by calling GetLastError().

Visual C++ Example

// set the MiniHub in blocking mode

VARIANT_BOOL blocking=VARIANT_TRUE;

m_Minihub.PutBlocking (blocking);

// set the MiniHub in non-blocking mode

blocking=VARIANT_FALSE;

m_Minihub.PutBlocking (blocking);

// returns the blocking value

blocking = m_Minihub.GetBlocking ( );

// user should handle events if non-blocking!

Visual Basic .NET Example

‘set Labware MiniHub in blocking mode

Minihub1.Blocking=True

‘set Labware MiniHub in non-blocking mode

Minihub1.Blocking=False

‘returns the blocking value

Dim bMode as Boolean

bMode = Minihub1.Blocking

‘user should handle events if non-blocking!

ControlPicture

IPictureDisp*ControlPicture

Description

A read-only picture of the Labware MiniHub that can be used in the container’s application.

Parameters

None

Visual C++ Example

/* the CPicture class will be imported into your project

when the ActiveX is installed */

CButton button;

// create a button

CPicture MinihubPic;

// retrieve the picture

MinihubPic = m_Minihub.GetControlPicture();

// paint the bitmap onto the button

button.SetBitmap((HBITMAP) MinihubPic.GetHandle());

Visual Basic .NET Example

Dim iPicture As System.Drawing.Image = Minihub1.ControlPicture()

button.BackgroundImage = iPicture

Related information

 

For information about...	See...
MiniHub ActiveX control	About the Labware MiniHub ActiveX control
Integrating the MiniHub ActiveX control	Installation instructions in the release notes
MiniHub ActiveX methods	Methods
MiniHub ActiveX events	Events