一开始我运行我的代码没有问题，但是在我关闭模拟器并尝试重新运行之后，它给了我这样的信息：
Installation failed with message device 'emulator-5554' not found.
It is possible that this issue is resolved by uninstalling an existing version of the apk if it is present, and then re-installing.
WARNING: Uninstalling will remove the application data!
Do you want to uninstall the existing application?
我该怎么办？请帮忙。