Since Android Emulator 2.0 this should be supported:
Drag & Drop With the new emulator, you can not only drag and drop APKs for quick installation, but you can also drag and drop any file to your emulator’s internal SD card to help in testing. link
I have the following problem. When I drop something (like pdf, image or apk) to the emulator at my workplace it won´t work, the mouse icon changes see screenshot.
It also won´t work for my colleague. But at home at my personal computer it works like charm.
I already changed the avd, to phone, another apk level, with devices frame, nothing works. Drag and drop in gernal works on my pc though, if I drag something into chrome (pdf) it will open it as intented.
