我的代碼是正確的。如何解決com.android.ide.common.internal.LoggedErrorException
錯誤：執行任務'：app：dexDebug'失敗。
com.android.ide.common.internal.LoggedErrorException: Failed to run command: C:\Users\mohammed\AppData\Local\Android\sdk2\build-tools\21.1.2\dx.bat --dex --no-optimize --output C:\Users\mohammed\AndroidStudioProjects\Test4\app\build\intermediates\dex\debug --input-list=C:\Users\mohammed\AndroidStudioProjects\Test4\app\build\intermediates\tmp\dex\debug\inputList.txt Error Code: 2 Output: UNEXPECTED TOP-LEVEL EXCEPTION: com.android.dex.DexException: Multiple dex files define Lcom/android/volley/VolleyError; at com.android.dx.merge.DexMerger.readSortableTypes(DexMerger.java:596) at com.android.dx.merge.DexMerger.getSortedTypes(DexMerger.java:554) at com.android.dx.merge.DexMerger.mergeClassDefs(DexMerger.java:535) at com.android.dx.merge.DexMerger.mergeDexes(DexMerger.java:171) at com.android.dx.merge.DexMerger.merge(DexMerger.java:189) at com.android.dx.command.dexer.Main.mergeLibraryDexBuffers(Main.java:454) at com.android.dx.command.dexer.Main.runMonoDex(Main.java:303) at com.android.dx.command.dexer.Main.run(Main.java:246) at com.android.dx.command.dexer.Main.main(Main.java:215) at com.android.dx.command.Main.main(Main.java:106)