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

在我的例子中,导入应用程序域名后跟“。R解决了这个问题。例子:

import com.example.myapp.R;

其他回答

我有我的XML文件在一个布局文件夹,而不是菜单文件夹。

这是我们从Eclipse转移到Android Studio的结果。

解决方案对我来说很简单……将XML文件移动到MENU文件夹并重新编译。

考虑以下IDE功能:

用gradle文件同步项目 Build ->清洁项目 Build ->重建项目 File ->使缓存失效


我的简单解决方案是:

Check that there is no error line in the dependencies of the build.gradle of the app or in all the resource files in the /res directory; where some common errors are when the attribute values are left without references when using: "@string/.." "@style/.." Make sure you are not getting an error of the type Android resource linking failed when the project is rebuilt. Open the file that contains the line with the error Cannot resolve symbol 'R' Scrolling to the last line of the class with said error line Click on a position to the right of the closing key } of the class

通过这种方式,IDE警告对话框将执行r类的导入。

GL

你们最近更新了SDK工具吗?启动android SDK管理器,确保你有最新的SDK工具,现在是独立于平台工具。当我第一次更新我的SDK管理器时,我也遇到了同样的问题,SDK构建工具包在安装/更新时没有出现,直到我关闭并重新打开SDK管理器。

我在可绘制资源中添加了一些图像,其中一个图像被命名为“super.jpg”,这是一个原因。

重命名图像并在此之后将项目与gradle文件同步修复了错误。

上面的答案对我没有帮助。我最终意识到问题在于Android Studio中缺少“build”文件夹。我在项目“iml”文件中发现了一些行,不包括“build/*”。删除这些错误后,生成文件就出现了,错误就消失了。