How To DDP_Text Not implemented for COleDateTime and COleCurrency (168298)

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 implement 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 files are available for download from the Microsoft Download Center:

DdpText.exe

For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base:

119591 How to Obtain Microsoft Support Files from Online Services

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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.