Eclipse develops Android projects, the solution that emulator control is gray cannot be used!

I want to use the Emulator Control tab in DDMS, but the result is gray and cannot be operated. What should I do? Look at the picture below~

Click directly on the marked part, and the dialog box that pops up will have what you want to find.

Reference: https://blog.csdn.net/asdfsfsdgdfgh/article/details/51851406