升級adt插件后，eclipse突然出現Unable to build: the file dx.jar was not loaded from the SDK folder 錯誤

升級adt插件后，eclipse突然出現Unable to build: the file dx.jar was not loaded from the SDK folder 錯誤 Unknown error: Unable to build: the file dx.jar ...

Unable to build: the file dx.jar was not loaded from the SDK folder

eclipse 運行 android 時失敗了，提示 Unable to build: the file dx.jar was not loaded from the SDK folder! 解決辦法就是 確保dx.jar這個文件在platform-tools\lib和選擇的開發版本lib中 ...