我已经在Ubuntu16.04x64上安装了AndroidStudio。当开始新项目时，我在setContentView(R.layout.activity_main);中得到未解析的“R”。gradle输出还说:Configurationondemandisanincubatingfeature.Incrementaljavacompilationisanincubatingfeature.:cleanUP-TO-DATE:app:clean:app:preBuildUP-TO-DATE:app:preDebugBuildUP-TO-DATE:app:checkDebugManife