Flutter出现Build failed with an exception。

The error is as follows:

I also searched on the Internet, and what I found could not solve my problem, but I suddenly thought that this problem occurred when I used Android before, so I tried that method Really solved.

Solution

1. The first step: turn off android studio

2. The second one: find the address of your project and delete the build

If you find it is occupied, you can open the task manager and close the dart.exe file

3. You can restart android studio and click the run button.