HOWTO: Display and Use the OLE Insert Object Dialog Box in VB

• Microsoft Visual Basic Learning, Professional, and Enterprise Editions for Windows, versions 5.0, 6.0

SUMMARY

The Insert Object dialog box is used widely in OLE based applications. This article shows you how to display the standard Insert Object dialog box using Visual Basic. It also demonstrates the use of the OLE APIs that need to pass LPOLESTR * from Visual Basic.

MORE INFORMATION

The following example displays an Insert Object dialog box and inserts what you select in a rich text box.

Steps to Create the Sample

1. Create a Visual Basic Standard EXE project. Form1 is created by default.



2. From the Projects menu, choose Components then select the Microsoft Rich Text Control x.x. Click OK.



3. Add a rich text box and a command button to Form1.



4. Add the following code to the General Declarations section of Form1:
   

   
      Option Explicit
   
      ' This is the main API used to display the Insert Obj DlgBox
      Private Declare Function OleUIInsertObject Lib "oledlg.dll" _
      Alias "OleUIInsertObjectA" (inParam As Any) As Long
   
      ' This is used to get the ProgID from Class ID.
      ' Note that this API need us to pass LPOLESTR * from Visual Basic.
      Private Declare Function ProgIDFromCLSID Lib "ole32.dll" _
      (clsid As Any, strAddess As Long) As Long
   
      ' The memory allocated OLE way need to be released OLE way
      ' with this API.
      Private Declare Sub CoTaskMemFree Lib "ole32.dll" (ByVal pvoid As Long)
   
      ' Widely used CopyMemory API.
      Private Declare Sub CopyMemory Lib "kernel32" Alias _
      "RtlMoveMemory" (Destination As Any, Source As Any, _
      ByVal Length As Long)
   
      ' Note that you need to get the strlength of the UNICODE string.
      Private Declare Function lstrlenW Lib "kernel32" _
      (ByVal lpString As Long) As Long
   
      ' Constants used in the dwFlags of OleUIInsertObjectType.
      Const IOF_SHOWHELP = &H1
      Const IOF_SELECTCREATENEW = &H2
      Const IOF_SELECTCREATEFROMFILE = &H4
      Const IOF_CHECKLINK = &H8
      Const IOF_CHECKDISPLAYASICON = &H10
      Const IOF_CREATENEWOBJECT = &H20
      Const IOF_CREATEFILEOBJECT = &H40
      Const IOF_CREATELINKOBJECT = &H80
      Const IOF_DISABLELINK = &H100
      Const IOF_VERIFYSERVERSEXIST = &H200
      Const IOF_DISABLEDISPLAYASICON = &H400
      Const IOF_HIDECHANGEICON = &H800
      Const IOF_SHOWINSERTCONTROL = &H1000
      Const IOF_SELECTCREATECONTROL = &H2000
   
      ' Return codes from OleUIInsertObject
      Const OLEUI_FALSE = 0
      Const OLEUI_SUCCESS = 1               ' No error, same as OLEUI_OK.
      Const OLEUI_OK = 1                    ' OK button pressed.
      Const OLEUI_CANCEL = 2                ' Cancel button pressed.
   
      ' GUID, IID, CLSID, etc
      Private Type GUID
          Data1 As Long
          Data2 As Integer
          Data3 As Integer
          Data4(0 To 7) As Byte
      End Type
   
      ' Main UDT used in OleUIInsertObject.
      Private Type OleUIInsertObjectType
      ' These IN fields are standard across all OLEUI dialog box functions.
          cbStruct As Long
          dwFlags As Long
          hWndOwner As Long
          lpszCaption  As String    ' LPCSTR
          lpfnHook As Long          ' LPFNOLEUIHOOK
          lCustData As Long         ' LPARAM
          hInstance  As Long
          lpszTemplate As String    ' LPCSTR
          hResource As Long         ' HRSRC
          clsid As GUID
    
      ' Specifics for OLEUIINSERTOBJECT.
          lpszFile As String        ' LPTSTR
          cchFile As Long
          cClsidExclude As Long
          lpClsidExclude As Long    ' LPCLSID
          IID As GUID
    
      ' Specifics to create objects if flags say so.
          oleRender As Long
          lpFormatEtc As Long       ' LPFORMATETC
          lpIOleClientSite As Long  ' LPOLECLIENTSITE
          lpIStorage As Long        ' LPSTORAGE
          ppvObj As Long            ' LPVOID FAR *
          sc As Long                ' SCODE
          hMetaPict As Long         ' HGLOBAL
      End Type
   
      Private Sub Command1_Click()
      Dim UIInsertObj As OleUIInsertObjectType
      Dim retValue As Long
      Dim lpolestr As Long
      Dim strsize As Long
      Dim ProgId As String
   
      On Error GoTo err
   
      ' Prepare the OleUIInsertObjectType.
      UIInsertObj.cbStruct = LenB(UIInsertObj)
      UIInsertObj.dwFlags = IOF_SELECTCREATENEW
      UIInsertObj.hWndOwner = Me.hWnd
      UIInsertObj.lpszFile = String(256, " ")
      UIInsertObj.cchFile = Len(UIInsertObj.lpszFile)
   
      ' Call the API to display the dialog box.
      retValue = OleUIInsertObject(UIInsertObj)
   
      If (retValue = OLEUI_OK) Then
          ' If we select to insert from a new object
          If ((UIInsertObj.dwFlags And IOF_SELECTCREATENEW) = _
                    IOF_SELECTCREATENEW) Then
   
          ' You need to get the ProgID.
          ' Note that we pass in a long byref.
            retValue = ProgIDFromCLSID(UIInsertObj.clsid, lpolestr)
   
          ' The size you need to initialize is the strlen + 1.
            strsize = lstrlenW(lpolestr) + 1
            ProgId = String(strsize, 0)
   
          ' Copy the string to BSTR. Notice the StrPtr function.
          ' Also notice that every UNICODE char is 2 bytes.
            CopyMemory ByVal StrPtr(ProgId), ByVal lpolestr, strsize * 2
   
          ' We need to free the memory allocated by ProgIDFromCLSID API.
            CoTaskMemFree lpolestr
           
            RichTextBox1.OLEObjects.add , , "", ProgId
   
          Else  ' If we select to insert from file
            RichTextBox1.OLEObjects.add , , UIInsertObj.lpszFile
          End If
         End If
   
      Exit Sub
   
      err:
          MsgBox err.Description
      End Sub 




5. Press F5 to run the project. Click the command button and a dialog box displays. Select an insertable object from the list and click OK. The object is inserted into your rich text box.

REFERENCES

For more information on the constants used in this sample, please refer to the Oledlg.h file that ships with Microsoft Visual C++.

There are many other APIs in oledlg.dll that you can use in your project to display standard dialog boxes. For more information on these APIs, search for OLEUI* in the Visual Studio MSDN.

For more information on how to get the address of variables in Visual Basic, please see the following article in the Microsoft Knowledge Base:

Q199824 HOWTO: Get the Address of Variables in Visual Basic

Additional query words:

Keywords : kbole kbAPI kbKernBase kbVBp kbVBp500 kbVBp600 kbGrpVB
Version : WINDOWS:5.0,6.0
Platform : WINDOWS
Issue type : kbhowto