只需更新ADT插件。这对我很管用!!

Start Eclipse, then select Help > Install New Software. Click Add, in the top-right corner. In the Add Repository dialog that appears, enter "ADT Plugin" for the Name and the following URL for the Location: https://dl-ssl.google.com/android/eclipse/ Note: The Android Developer Tools update site requires a secure connection. Make sure the update site URL you enter starts with HTTPS. Click OK. In the Available Software dialog, select the checkbox next to Developer Tools and click Next. In the next window, you'll see a list of the tools to be downloaded. Click Next. Read and accept the license agreements, then click Finish. If you get a security warning saying that the authenticity or validity of the software can't be established, click OK. When the installation completes, restart Eclipse

希望有帮助!

我尝试了以上所有的方法，但没有一个对我有效。我想出了一个永远有效的方法。基本上，罪魁祸首是ADT处理“libs”文件夹的方式，所以我放弃使用“libs”文件夹。相反，我创建了一个“libraries”文件夹并使用它。

你可以这样做，它总是工作-即使ADT应该改变它如何改变它处理“libs”文件夹在未来:

Create a "libraries" folder. Create a sub-folder under it for each library. Put all of the files for each library in the appropriate folder (java jar file, source jar file, javadoc jar file, etc). Add the java jar file for each project in the "Libraries" tab for the Java Build Path by clicking on the Add Jars... button to add the jar from the library sub-folder in the "libraries" folder. Attach the source/javadocs to each project by opening the project in the "Libraries" tab, selecting the desired item, and clicking on the Edit... button to add the source/javadocs from the library sub-folder in the "libraries" folder. Check the checkbox for each project in the "Order and Export" tab for the Java Build Path. After verifying that all libraries have been moved delete the "libs" folder.

按照上面的步骤，你的项目会有这样的文件夹:

你的Java构建路径看起来像这样:

在Order和Export中，库被勾选:

我知道这个问题已经很老了，但是当我昨天遇到同样的问题时，上面发布的解决方案对我来说太烦人了，我发现可以很容易地在项目的.classpath文件中添加源路径定义。然后Eclipse将对其进行改编，您就可以浏览源代码了。

之前的类路径条目:

<classpathentry kind="lib" path="[PATH_TO_MY_JAR]"/>

将路径添加到源后

<classpathentry kind="lib" path="[PATH_TO_MY_JAR]" sourcepath="[PATH_TO_MY_SOURCE_JAR]"/>

希望这能有所帮助

答案来自http://code.google.com/p/android/issues/detail?id=27490#c21

在你的libs文件夹中，你必须有:

doc(folder)
    foo_doc(folder)
        index.html
        ...
        ...
foo.jar
foo.jar.properties

在你的罐子里。属性，只需输入doc=./doc/foo_doc

也许你将不得不刷新你的项目，清理它，关闭它并重新打开它。

这对我很管用!

只需更新ADT插件。这对我很管用!!

Start Eclipse, then select Help > Install New Software. Click Add, in the top-right corner. In the Add Repository dialog that appears, enter "ADT Plugin" for the Name and the following URL for the Location: https://dl-ssl.google.com/android/eclipse/ Note: The Android Developer Tools update site requires a secure connection. Make sure the update site URL you enter starts with HTTPS. Click OK. In the Available Software dialog, select the checkbox next to Developer Tools and click Next. In the next window, you'll see a list of the tools to be downloaded. Click Next. Read and accept the license agreements, then click Finish. If you get a security warning saying that the authenticity or validity of the software can't be established, click OK. When the installation completes, restart Eclipse

希望有帮助!

在ADT 22上，我无法访问common -io- 2.4.4 .jar和android-support-v4.jar的Javadoc

这是我解决它的方法:

前提条件:这两个库都列在“参考库”下。 右键单击commons-io-2.4.jar并选择Properties。此窗口显示:

commons-io-2.4.jar与commons-io-2.4-javadoc.jar捆绑在一起，因此我在归档外部文件路径中指定了Javadoc。

我对支持库做了同样的事情:右键单击android-support-v4.jar并选择Properties。此屏幕显示:

这一次，我指定了源目录的路径。