Android multiple DEX error multiple Dex files define landroid/support/v7/app/actionbar$displayoptions;

Today, when I wrote the program, my Android Studio suddenly compiled the error (the error is as follows:) and then after my several times to find out that every time you have to clear project and then build on it, if you build the second time to error. Then I found the strongest teacher (Google) to try to solve! Unfortunately, what I see on Google is the solution on eclipse. Didn't find the answer I wanted, do I have to clear project every time I build? Finally, after a couple of times, I found an option in Project Structure--->app--->properties called: Incremental Dex (added DEX) has a value of true, I've created a new project. The default value is NULL, and the problem of changing this to a null value is completely solved! Even now I don't know what the use of this option is.

Error message:

information:gradle tasks [: App:assembledebug]:app:prebuild up-to-DATE:app:preDebugBuild up-to-DATE:app:checkDebugManifest:app:preReleaseBuild up-to-DATE:app:prepareComAndroidSupportAnimatedVectorDrawable2330Library up-to-DATE:app:prepareComAndroidSupportAppcompatV72330Library up-to-DATE:app:prepareComAndroidSupportSupportV42330Library up-to-DATE:app:prepareComAndroidSupportSupportVectorDrawable2330Library up-to-DATE:app:prepareDebugDependencies:app:compileDebugAidl up-to-DATE:app:compileDebugRenderscript up-to-DATE:app:generateDebugBuildConfig up-to-DATE:app:generateDebugAssets up-to-DATE:app:mergeDebugAssets up-to-DATE:app:generateDebugResValues up-to-DATE:app:generateDebugResources up-to-DATE:app:mergeDebugResources up-to-DATE:app:processDebugManifest up-to-DATE:app:processDebugResources up-to-DATE:app:generateDebugSources up-to-DATE:app:processDebugJavaRes up-to-DATE:APP:COMPILEDEBUGJAVAWITHJAVAC:APP:COMPILEDEBUGNDK up-to-DATE:app:compileDebugSources:app:preDexDebug up-to-DATE:app:dexDebugUNEXPECTED TOP-Level EXCEPTION:com.android.dex.DexException:Multiple dex files define landroid/support/v7/app/actionbar$displayoptions; At Com.android.dx.merge.DexMerger.readSortableTypes (Dexmerger.java:591) at Com.android.dx.merge.DexMerger.getSortedTypes (Dexmerger.java:546) at Com.android.dx.merge.DexMerger.mergeClassDefs (Dexmerger.java:528) at Com.android.dx.merge.DexMerger.mergeDexes (Dexmerger.java:164) at Com.android.dx.merge.DexMerger.merge (Dexmerger.java:188) at Com.android.dx.command.dexer.Main.mergeLibraryDexBuffers (Main.java:504) at Com.android.dx.command.dexer.Main.runMonoDex (Main.java:334) at Com.android.dx.command.dexer.Main.run (Main.java:277) at Com.android.dx.command.dexer.Main.main (Main.java:245) at Com.android.dx.command.Main.main (Main.java:106) Error:execution failed forTask': App:dexdebug'.> com.android.ide.common.process.ProcessException:org.gradle.process.internal.ExecException:
Process'Command'C:\Program Files\java\jdk1.8.0_73\bin\java.exe"'Finished with Non-zero exit value2

Workaround:

Android multiple DEX error multiple Dex files define landroid/support/v7/app/actionbar$displayoptions;