“无法解析符号R”在Android Studio

In every instance in all of my classes where I reference R.id.something, the R is in red and it says "cannot resolve symbol R". Also every time there is R.layout.something it is underlined in red and says "cannot resolve method setContentView(?)". The project always builds fine. It is annoying to see this all the time. I have read many other questions on here about something similar but most involved importing projects from Eclipse. I am using what I believe to be the most recent version of Android Studio and the project was created with Android Studio and worked without any "cannot resolve R" problems. I would like to know what causes this if anyone knows.

当前回答

我也遇到了这个问题，我用这种方法解决了它。首先进入Gradle，点击clean。其次，单击Build。

确保不要从android studio清洁

2018-10-14 15:34:36

其他回答

修复“无法解析符号r”的错误。试试这些解决方案。

Build ->清洁项目。 Build -> Build Project。 Build ->制作项目。工具栏左起第三个图标->同步项目与gradle文件。 File ->使缓存失效并重新启动。确保您在应用级gradle文件中使用兼容的gradle版本。

例如:“classpath 'com.android.tools.build:gradle:X.X.X'”。

我希望这些解决方案能帮助到你。

感谢阅读。

2019-02-26 11:51:42

只需清理你的项目和同步项目与Gradle文件。