关于android：The connection to adb is down, and a severe error has occured.

点击项目run，报了这样的错，前几天都好好的：

[2013-09-14 15:27:13 - QualityPicture_Client1.3.1.9.7.1] ------------------------------

[2013-09-14 15:27:13 - QualityPicture_Client1.3.1.9.7.1] Android Launch!
[2013-09-14 15:27:13 - QualityPicture_Client1.3.1.9.7.1] The connection to adb is down, and a severe error has occured.
[2013-09-14 15:27:13 - QualityPicture_Client1.3.1.9.7.1] You must restart adb and Eclipse.

[2013-09-14 15:27:13 - QualityPicture_Client1.3.1.9.7.1] Please ensure that adb is correctly located at 'D:\adt-bundle-windows-x86\sdk\platform-tools\adb.exe' and can be executed.

其实很简单，你要改一下系统的环境变量path，由'D:\adt-bundle-windows-x86\sdk\tools改成了'D:\adt-bundle-windows-x86\sdk\platform-tools

你查看\tools目录发现多了一个adb_has_moved.txt文件，里面明确告诉了原因：The adb tool has moved to platform-tools。原来从SDK R8以后，SDK需要有一个新的组件支持，这个组件叫做Platform-tools，adb已经迁移到这个目录下去了。并且 adb_has_moved.txt文件也说明需要在PATH环境变量中增加\platform-tools路径，以便能够从任何地方启动adb.exe。  

然后重启电脑，启动eclipse，点击run，又报如下错误：

[2013-09-14 15:27:13 - QualityPicture_Client1.3.1.9.7.1]  ADB server didn't ACK
[2013-09-14 15:27:13 - QualityPicture_Client1.3.1.9.7.1] * failed to start daemon *
 
于是我就百度，参考了该篇文章(http://www.cnblogs.com/longqi293/archive/2012/06/19/2554801.html点击打开链接)。可是我没有出现那样的情况。但我还是照着上面的操作，杀死服务，然后启动服务。然后我就重启一下，就可以了。

还有人说按如下图片的方法：