一、前言：

android studio升级到4.0.1版本, 各种报错, 代码各种修改.

其中有一个这样的错误, 没有见过, 后来在StackOverflow看到了一样的报错,找到了解决方法;

报错信息

(androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
Duplicate class android.support.v4.app.INotificationSideChannel$Stub found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
Duplicate class android.support.v4.app.INotificationSideChannel$Stub$Proxy found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
Duplicate class android.support.v4.graphics.drawable.IconCompatParcelizer found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
Duplicate class android.support.v4.os.IResultReceiver found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
Duplicate class android.support.v4.os.IResultReceiver$Stub found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
Duplicate class android.support.v4.os.IResultReceiver$Stub$Proxy found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
Duplicate class android.support.v4.os.ResultReceiver found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
Duplicate class android.support.v4.os.ResultReceiver$1 found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
Duplicate class android.support.v4.os.ResultReceiver$MyResultReceiver found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
Duplicate class android.support.v4.os.ResultReceiver$MyRunnable found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
Duplicate class androidx.core.graphics.drawable.IconCompatParcelizer found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
Duplicate class androidx.core.internal.package-info found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
Duplicate class androidx.versionedparcelable.CustomVersionedParcelable found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
Duplicate class androidx.versionedparcelable.NonParcelField found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
Duplicate class androidx.versionedparcelable.ParcelField found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
Duplicate class androidx.versionedparcelable.ParcelImpl found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
Duplicate class androidx.versionedparcelable.ParcelImpl$1 found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
Duplicate class androidx.versionedparcelable.ParcelUtils found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
Duplicate class androidx.versionedparcelable.VersionedParcel found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
Duplicate class androidx.versionedparcelable.VersionedParcel$1 found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
Duplicate class androidx.versionedparcelable.VersionedParcel$ParcelException found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
Duplicate class androidx.versionedparcelable.VersionedParcelParcel found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
Duplicate class androidx.versionedparcelable.VersionedParcelStream found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
Duplicate class androidx.versionedparcelable.VersionedParcelStream$FieldBuffer found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
Duplicate class androidx.versionedparcelable.VersionedParcelStream$InputBuffer found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
Duplicate class androidx.versionedparcelable.VersionedParcelable found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
Duplicate class androidx.versionedparcelable.VersionedParcelize found in modules class

解决方法:

# 需要在gradle.properties中添加下面两行代码
# 这是因为混合支持库。通过添加这些行选择androidX作为您的支持库
 
android.useAndroidX=true
android.enableJetifier=true