The user initiates the conversation by supplying the name of the application (Quote) that will supply the data and the particular topic of interest (NYSE). The resulting DDE conversation is used to request quotes on specific stocks.The following example illustrates two cooperating Windows DDE applications, as seen from the user's point of view.
A Microsoft Excel spreadsheet user wants to track the price of a particular stock on the New York Stock Exchange. The user has a Windows application called Quote that in turn has access to NYSE data. The DDE conversation between Microsoft Excel and Quote takes place as follows:
The user initiates the conversation by supplying the name of the application (Quote) that will supply the data and the particular topic of interest (NYSE). The resulting DDE conversation is used to request quotes on specific stocks.
Microsoft Excel broadcasts the application and topic names to all DDE applications currently running in the system. Quote responds, establishing a conversation with Excel about the NYSE topic.
The user can then create a spreadsheet formula in a cell that requests that the spreadsheet be automatically updated whenever a particular stock quotation changes. For example, the user could request an automatic update whenever a change in the selling price of ZAXX stock occurs, by specifying the following Microsoft Excel formula:
='Quote'|'NYSE'!ZAXXThe user can terminate the automatic updating of the ZAXX stock quotation at any time. Other data links that were established separately (such as for quotations for other stocks) still will remain active under the same NYSE conversation.
The user can also terminate the entire conversation between Excel and Quote on the NYSE topic, so that no specific data links may be subsequently established on that topic without initiating a new conversation.