參考：https://blog.csdn.net/lvshuchangyin/article/details/53785494

匯入第三方庫的時候出現的問題

Error:Error converting bytecode to dex:
Cause: com.android.dex.DexException: Multiple dex files define Lcom/alibaba/android/arouter/routes/ARouter$$Group$$user;
Error:com.android.dex.DexException: Multiple dex files define Lcom/alibaba/android/arouter/routes/ARouter$$Group$$user;
Error:	at com.android.dx.merge.DexMerger.readSortableTypes(DexMerger.java:661)
Error:	at com.android.dx.merge.DexMerger.getSortedTypes(DexMerger.java:616)
Error:	at com.android.dx.merge.DexMerger.mergeClassDefs(DexMerger.java:598)
Error:	at com.android.dx.merge.DexMerger.mergeDexes(DexMerger.java:171)
Error:	at com.android.dx.merge.DexMerger.merge(DexMerger.java:198)
Error:	at com.android.builder.dexing.DexArchiveMergerCallable.call(DexArchiveMergerCallable.java:61)
Error:	at com.android.builder.dexing.DexArchiveMergerCallable.call(DexArchiveMergerCallable.java:36)
Error:	at java.util.concurrent.ForkJoinTask$AdaptedCallable.exec(ForkJoinTask.java:1424)
Error:	at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289)
Error:	at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056)
Error:	at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1692)
Error:	at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:157)
Error:Execution failed for task ':app:transformDexArchiveWithDexMergerForDebug'.
> com.android.build.api.transform.TransformException: com.android.dex.DexException: Multiple dex files define Lcom/alibaba/android/arouter/routes/ARouter$$Group$$user;
 

解決方法：

在build.gradle裡新增設定(如果使用模組化開發，在主模組的build.gradle新增)：

defaultConfig {
        ...

        //Enabling multidex support.
        multiDexEnabled true
    }


dependencies {
    ...
    compile 'com.android.support:multidex:1.0.1'


}