How Do I Allow Drag and Drop Only Within Magic xpa so that External Applications Cannot Retrieve the Data? (Magic xpa 4.x)
External applications will not read dropped data unless the data format matches a data format they know how to handle. Each application handles the various data formats differently, and if the application does not recognize a given data format, it will not allow the drop.
So, if you use format 0, the “User-defined format”, then no external application will recognize the data format and drop will not be allowed.
Note: The user format must be defined in the Drop Data supported user formats environment setting.
In this example, we used DragSetData() to set the format to zero. We also set Propagate to No, so the built-in drag function won’t work.
Once we do this, the data will not drag to another field in Magic xpa either, unless we use the same user format within the Drop handler.
The Online Samples project (program HG08)
