When executing a DDE transaction with Internet Explorer (16-bit or 32- bit), Internet Explorer does not seem to communicate to the application as expected.

Internet Explorer's DDE implementation is based upon the Spyglass SDI spec, which mandates that all specified quoted strings use the \" character combination. Not correctly prefixing a string with the \" character combination when IE expects a quoted string, could cause this problem.

When specifying a quoted string, whether as an application, topic, item name, or as an argument, always use the \" character combination.

This behavior is by design.

The Spyglass SDI specification defines a standard notation to indicate argument types. Specifically, all names prefixed with qs, indicating a quoted string, should use the \" character combination to embed a quote character within a quoted string.

To obtain more information on the standard notation for various other argument types, please refer to the "Notation" section of the Spyglass SDI specification.

Steps to Reproduce Behavior

1. Establish a DDE communication with Internet Explorer, specifying the following:

   application Name: iexplore
   topicName:        WWW_RegisterURLEcho
   						

2. Note how the Spyglass SDI specification specifies the arguments for this particular topic:

   RegisterURLEcho ( TO Web browser )
   Topic: WWW_RegisterURLEcho
   Item: qsApplication
   Transaction: XTYP_REQUEST
   Data: bSuccess
   						

   Note how the ItemName specified is prefixed with qs, indicating a quoted string, as described above.
3. Set up an XTYP_REQUEST transaction with DdeClientTransaction, specifying:

   itemName: \"DDESERVER\"
   						

   This should cause the DDESERVER application to be notified of URLEcho events, as specified in the Spyglass SDI specification. Note That incorrectly specifying "DDESERVER" without the \" character combination required of quoted strings causes no such notifications to be sent to the DDESERVER application.

For the WWW_OpenUrl topic, where specifying a URL string should cause IE to navigate to the specified URL, incorrectly specifying the string (that is, without the expected \" character combination) causes IE to not interpret the parameters correctly, thereby not causing it to navigate to the URL.

For additional information, please see the following article in the Microsoft Knowledge Base: