Android Error: Unable to open class file R.java

You’ve just installed Eclipse , and attempted to create your first Android Application. When clicking create, you see an error similar to this: "Error: Unable to open class file R.java "

如果出现 “Error: Unable to open class file R.java No such file or directory”。

Solution:解决方法：

The “Build Path” for your Java environment is not setup correctly in Eclipse. To fix this, follow these steps:

1) Open the Preferences Window by clicking “Window -> Preferences”

2) Find the “Java” section and expand it

3) Select “Build Path ”

4) Change the value of Source and output folder from Folders to “Project ”

5) Click Apply and then “OK ”

Your problem should be resolved!