FILE: DDP_Text Not implemented for COleDateTime and COleCurrency

ID: Q168298

The information in this article applies to:

The Microsoft Foundation Classes (MFC), included with:
- Microsoft Visual C++, 32-bit Editions, version 5.0

SUMMARY

DDP_Text functions for COleCurrency and COleDateTime are not implemented in MFC. However code that uses these functions is added to DoDataExchange when ClassWizard is used to associate a CURRENCY or DATE property with a control on a property page. This results in the following compilation errors.

For CURRENCY property:

<filename(lineno)> : error C2665: 'DDP_Text' : none of the 9 overloads
can convert parameter 3 from type 'class COleCurrency'

For DATE property:

<filename(lineno)> : error C2665: 'DDP_Text' : none of the 9 overloads
can convert parameter 3 from type 'class COleDateTime'

You must the DDP functions for COleCurrency and COleDateTime in order to associate a control on a property page with a property of one of these types.

The DdpText.exe sample extracts a Visual C++ 5.0 ActiveX control project; it contains code for overrides of DDP_Text for COleCurrency and COleDateTime.

MORE INFORMATION

The following file is available for download from the Microsoft Software Library:

DdpText.exe

For more information about downloading files from the Microsoft Software Library, please see the following article in the Microsoft Knowledge Base:

Q119591 How to Obtain Microsoft Support Files from Online Services

When you associate CURRENCY and DATE properties with edit controls on a property page, ClassWizard adds the following member variables to the COlePropertyPage derived class:


   COleCurrency m_Currency;
   COleDateTime m_Date;

It adds the following to the DoDataExchange for the property page:


   DDP_Text(pDX, IDC_CURRENCY, m_Currency, _T("CurrencyProp") );
   DDX_Text(pDX, IDC_CURRENCY, m_Currency);
   DDP_Text(pDX, IDC_DATE, m_Date, _T("DateProp") );
   DDX_Text(pDX, IDC_DATE, m_Date);

This results in a compile error because the compiler cannot find overrides of DDP_TEXT for COleCurrency and COleDateTime.

To use the code in the sample it is necessary to derive your code from CMyOlePropertyPage instead of COlePropertyPage. The project also has code for CMyOlePropertyPage.

MyPropPg.h and MyPropPg.cpp have the code required to add code for DDP_Text to your project. Add these files to your project.

Use ClassWizard to associate properties with controls on your property page. Now modify the property page class so that it is derived from CMyOlePropertyPage. The following steps are required:

Add the following line to your property page header file:
```
      #include "MyPropPg.h" 
```

Replace all instances of COlePropertyPage in the header and .CPP file for your project with CMyOlePropertyPage.

Additional query words:


Keywords          : kbcode kbfile kbole kbMFC kbVC kbVC500 kbVC600 
Version           : 5.0
Platform          : NT WINDOWS 
Issue type        :

Last Reviewed: July 30, 1999