To set the Picture property of an ActiveX control, you can
use the Component Gallery to insert an ActiveX control into an
AppWizard-generated application with control container support. If the control
has a picture property, the wrapper classes generated by the Component Gallery
will contain the SetPicture() and GetPicture() methods. The More Information
section contains details that explain how to use the picture property of
an ActiveX control.
Using the Grid Control (Grid32.ocx is shipped with Visual
C++ 4.x) as an example, you can implement the SetPicture() and GetPicture()
methods in the control classes provided by the Component Gallery by using this
code:
void CGridCtrl::SetPicture(LPDISPATCH propVal)
{
SetProperty(0x15, VT_DISPATCH, propVal);
}
CPicture CGridCtrl::GetPicture()
{
LPDISPATCH pDispatch;
GetProperty(0x15, VT_DISPATCH, (void*)&pDispatch);
return CPicture(pDispatch);
}
It is not intuitively clear how to use these methods to get or set the
picture property. The following steps show how to set the picture property of
an ActiveX control successfully in an AppWizard-generated application. The
particular control used in this example is the Microsoft Grid Control, and its
picture property is being set to the toolbar bitmap provided by AppWizard.
- Generate a new non-dialog based AppWizard application. Be
sure to select both Container and Control support in AppWizard Step 3.
- Add the Grid Control from the OLE Controls tab (or
Registered ActiveX Controls in VC++ 5.0) in the Component Gallery.
- Add Afxctl.h to the list of pre-compiled header files in
Stdafx.h.
- Add a Grid Control object to the About Dialog box in the
dialog editor.
- Using ClassWizard, add a control member variable called
m_grid to the Grid Control in the About Dialog box.
- Override the container's initialization routine to create
and initialize a CPictureHolder object. Call the SetPicture() method for the
control, passing in the CPictureHolder's dispatch pointer. SetPicture calls
SetProperty() for the control. Here's an example:
BOOL CAboutDlg::OnInitDialog()
{
CDialog::OnInitDialog();
// Create and Initialize the CPictureHolder variable with the
// toolbar resource
CPictureHolder pictholder;
pictholder.CreateFromBitmap(IDR_MAINFRAME);
//Pass dispatch pointer to CPictureHolder
m_grid.SetPicture(pictholder.GetPictureDispatch());
// NOTE: GetPictureDispatch() QI()'s for the IPictureDisp
// interface, so the picture object will remain alive until
// the property is reset or the control is destroyed. When
// pictholder goes out of scope, it calls Release() on the
// picture object, but the previously mentioned QI() will have
// bumped the ref count, allowing it to remain alive until the
// control itself releases the picture object.
return TRUE;
}
For Visual C++ 4.xx: OLE Control Containers: Programming
OLE Controls in an OLE Control Container - Visual C++ Books Online, MFC
Encyclopedia.
OLE Controls: Using Pictures in an OLE Control -
Visual C++ Books Online, MFC Encyclopedia.
For Visual C++ 5.0:
ActiveX Control Containers: Programming ActiveX Controls in an ActiveX Control
Container - Visual C++ Books Online, Visual C++ Programmer's Guide.
ActiveX Controls: Using Pictures in an ActiveX Control - Visual C++ Books
Online, Visual C++ Programmer's Guide.
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