You can use the DDESend function to initiate a dynamic data exchange (DDE) conversation with another application and send an item of information to that application from a control on a form or report.
Use the DDESend function in the ControlSource property setting of a text box, option group, check box, or combo box on a form.
For example, you can use the DDESend function in the ControlSource property of a text box to send the data displayed in that text box to a specified cell in a Microsoft Excel spreadsheet.
DDESend(application, topic, item, data)
The DDESend function has the following arguments.
| Argument | Description |
| application | String expression identifying an application that can participate in a DDE conversation. Usually, application is the name of an .exe file (without the .exe extension) for a Microsoft Windows-based application, such as Microsoft Excel. For example, to initiate a DDE conversation with Microsoft Excel, type “Excel” for the application argument. |
| topic | String expression that is the name of a topic recognized by application. Topic is often a document or data file. Check the other application’s documentation for a list of possible topics. |
| item | String expression that is the name of a data item recognized by application. Check the other application’s documentation for a list of possible items. |
| data | String or expression containing the data to send to application. |
The DDESend function initiates a DDE conversation with application and topic, and identifies item as the data item which will receive data. For example, if application is Microsoft Excel, topic might be "Sheet1", and item might be a row-and-column identifier, such as "R1C1", or the name of a range of cells.
The data argument specifies the information you want to send. It can be a literal string, such as "Report prepared by John". Or it can be an expression that includes the result of a function that creates a string, such as "Prepared on " & Date(). If item refers to more than one piece of information, such as a named range in a Microsoft Excel worksheet that contains multiple cells, DDESend sends data to the first entry.
In the following example, the DDESend function sends the string "Some text" to the cell at Row 1, Column 1 in a Microsoft Excel worksheet. You can enter this expression for a text box control in the ControlSource property box on the control’s property sheet.
= DDESend("Excel", "Sheet1", "R1C1", "Some text")
Suppose you want to send data from a bound control on a Microsoft Access form to a cell on a Microsoft Excel spreadsheet. The ControlSource property of the bound control already contains a field name or expression. You can create another text box or combo box, and set its ControlSource property an expression including DDESend, where data is the name of the bound control. For instance, if you have a bound text box called Last Name, you can create another text box and set its ControlSource property to the following.
= DDESend("Excel", "Sheet1", "R1C1", [LastName])
This intermediary control must be either a text box or a combo box. You can’t use the name of a bound control as the data argument for a check box or option group.
You can use the DDESend function only in the ControlSource property setting of a text box, option group, check box, or combo box on a form. You cannot call the DDESend function from Visual Basic.
When you use DDESend, the control becomes read-only in Form view and Print Preview. Because the ControlSource property is also read-only in Form view and Print Preview, changes to the control must be made in Design view.
The maximum number of DDE conversations that can be open simultaneously is determined by Microsoft Windows and your computer’s memory and resources. If the conversation can’t be initiated because application isn’t running or doesn’t recognize topic or if the maximum number of conversations has already been reached, DDESend returns a Null.
Note The other application may be configured to ignore your DDE conversation. If so, DDESend returns a Null. Similarly, you can set Microsoft Access to ignore requests from other applications: click Options on the Tools menu, and on the Advanced tab of the Options dialog box, under DDE Operations, select Ignore DDE Requests.
Tip If you need to manipulate another application’s objects from Microsoft Access, you may want to consider using OLE Automation.
The following table illustrates how DDESend behaves when you use it with each of the controls.
| Control | Remarks |
| Text box |
Because the text box appears blank in
Form view and Print Preview, you may want to set its Visible
property to False. The data argument can refer to another control. The following example shows how you can send the contents of a control called LastName to a Microsoft Excel worksheet. = DDESend("Excel", "Sheet1", "R1C1", [LastName]) |
| Combo box |
Because the combo box appears blank in
Form view and Print Preview, you may want to set its Visible
property to False. The data argument can refer to another control. The following example shows how you can send the contents of a control called LastName to a Microsoft Excel worksheet. = DDESend("Excel", "Sheet1", "R1C1", [LastName]) |
| Option group |
None of the option buttons in the option
group is selected in Form view and Print Preview. You may
want to make the option group (and its buttons) invisible
by setting its Visible property to False. The data argument must contain numeric data, such as "2". If the data argument isn’t numeric, DDESend doesn’t send the information and item isn’t changed. |
| Check box |
The check box is dimmed in Form view and
Print Preview. You may want to make it invisible by
setting its Visible property to False. The data argument must contain numeric data, such as "2". If the data argument isn’t numeric, DDESend doesn’t send the information and item isn’t changed. |
DDE Function; DDEExecute Statement; DDEInitiate Function; DDEPoke Statement; DDERequest Function; DDETerminate Statement; DDETerminateAll Statement; Enabled, Locked Properties.
See the DDE function example.