The project cannot be built until&n

解决方法：修改.classpath

修改之前的.classpath

<?xml version="1.0" encoding="UTF-8"?> 
  <classpath> 
    <classpathentry kind="src" path="src"/>   
    <classpathentry kind="con" path="com.android.ide.eclipse.adt.ANDROID_FRAMEWORK"/>   
    <classpathentry kind="con" path="org.eclipse.pde.core.requiredPlugins"/>   
    <classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/jre6"/>   
    <classpathentry kind="src" path="gen"/> 
    <classpathentry kind="output" path="bin"/> 
</classpath> 

修改之后：

<?xml version="1.0" encoding="UTF-8"?>   
  <classpath>