java.lang.RuntimeException: Unable to get provider android.support.v4.content.FileProvider

项目运行到其他手机没发现问题，运行到OPPOR8107时报以下错误：

java.lang.RuntimeException: Unable to get provider android.support.v4.content.FileProvider: java.lang.ClassNotFoundException: Didn't find class "android.support.v4.content.FileProvider" on path: DexPathList[[zip file "/data/app/***.apk"],nativeLibraryDirectories=[/data/app-lib/***-1, /vendor/lib, /system/lib]]                                                       at android.app.ActivityThread.installProvider(ActivityThread.java:4892)                                                       at android.app.ActivityThread.installContentProviders(ActivityThread.java:4484)                                                       at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4424)                                                       at android.app.ActivityThread.access$1500(ActivityThread.java:143)                                                       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1269)                                                       at android.os.Handler.dispatchMessage(Handler.java:102)                                                       at android.os.Looper.loop(Looper.java:136)                                                       at android.app.ActivityThread.main(ActivityThread.java:5120)                                                       at java.lang.reflect.Method.invokeNative(Native Method)                                                       at java.lang.reflect.Method.invoke(Method.java:515)                                                       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:818)                                                       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:634)                                                       at dalvik.system.NativeStart.main(Native Method)                                                    Caused by: java.lang.ClassNotFoundException: Didn't find class "android.support.v4.content.FileProvider" on path: DexPathList[[zip file "/data/app/***-1.apk"],nativeLibraryDirectories=[/data/app-lib/***-1, /vendor/lib, /system/lib]]                                                       at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)                                                       at java.lang.ClassLoader.loadClass(ClassLoader.java:497)                                                       at java.lang.ClassLoader.loadClass(ClassLoader.java:457)                                                       at android.app.ActivityThread.installProvider(ActivityThread.java:4877)                                                       at android.app.ActivityThread.installContentProviders(ActivityThread.java:4484)                                                        at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4424)                                                        at android.app.ActivityThread.access$1500(ActivityThread.java:143)                                                        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1269)                                                        at android.os.Handler.dispatchMessage(Handler.java:102)                                                        at android.os.Looper.loop(Looper.java:136)                                                        at android.app.ActivityThread.main(ActivityThread.java:5120)                                                        at java.lang.reflect.Method.invokeNative(Native Method) 

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本来以为是引入聊天sdk的问题，后来发现是MultiDex未初始化的问题：
1）首先修改Gradle配置文件，启用MultiDex并包含MultiDex支持：

defaultConfig {             multiDexEnabled true        }

2）在Application中重写attachBaseContext方法

@Override    protected void attachBaseContext(Context base) {        super.attachBaseContext(base);        MultiDex.install(base);    }

问题解决。