android studio中的未知錯誤：無法運行應用程序

無法運行應用程序。該應用程序成功地編譯，但是崩潰與此異常android studio中的未知錯誤：無法運行應用程序

FATAL EXCEPTION: main Process: com.example.myapplication, PID: 15209 java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.myapplication/com.example.myapplication.MainActivity}: java.lang.ClassNotFoundException: Didn't find class "com.example.myapplication.MainActivity" on path: DexPathList[[zip file "/data/app/com.example.myapplication-2/base.apk"],nativeLibraryDirectories=[/vendor/lib, /system/lib]] at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2426) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2601) at android.app.ActivityThread.access$800(ActivityThread.java:178) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1470) at android.os.Handler.dispatchMessage(Handler.java:111) at android.os.Looper.loop(Looper.java:194) at android.app.ActivityThread.main(ActivityThread.java:5637) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:960) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755) Caused by: java.lang.ClassNotFoundException: Didn't find class "com.example.myapplication.MainActivity" on path: DexPathList[[zip file "/data com.example.myapplication-2/base.apk"],nativeLibraryDirectories=[/vendor/lib, /system/lib]] at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56) at java.lang.ClassLoader.loadClass(ClassLoader.java:511) at java.lang.ClassLoader.loadClass(ClassLoader.java:469) at android.app.Instrumentation.newActivity(Instrumentation.java:1071) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2601) at android.app.ActivityThread.access$800(ActivityThread.java:178) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1470) at android.os.Handler.dispatchMessage(Handler.java:111) at android.os.Looper.loop(Looper.java:194) at android.app.ActivityThread.main(ActivityThread.java:5637) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:960) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755) Suppressed: java.lang.ClassNotFoundException: com.example.myapplication.MainActivity at java.lang.Class.classForName(Native Method) at java.lang.BootClassLoader.findClass(ClassLoader.java:781) at java.lang.BootClassLoader.loadClass(ClassLoader.java:841) at java.lang.ClassLoader.loadClass(ClassLoader.java:504) ... 13 more Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack available

這是我的Android清單。

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
package="com.example.myapplication"> 

<application 
    android:allowBackup="true" 
    android:icon="@mipmap/ic_launcher" 
    android:label="@string/app_name" 
    android:supportsRtl="true" 
    android:theme="@style/AppTheme"> 
    <activity android:name=".MainActivity"> 
     <intent-filter> 
      <action android:name="android.intent.action.MAIN" /> 

      <category android:name="android.intent.category.LAUNCHER" /> 
     </intent-filter> 
    </activity> 
</application> 

</manifest>

MainActivity

package com.example.myapplication; 

import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.widget.ImageView; 
import android.view.View; 
public class MainActivity extends AppCompatActivity { 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

    } 
}

我的gradle產出，建立

apply plugin: 'com.android.application' 

    android { 
    compileSdkVersion 24 
    buildToolsVersion "24.0.2" 

    defaultConfig { 
     applicationId "com.example.myapplication" 
     minSdkVersion 15 
     targetSdkVersion 24 
     versionCode 1 
     versionName "1.0" 
    } 
    buildTypes { 
     release { 
      minifyEnabled false 
      proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' 
     } 
    } 
} 

dependencies { 
    compile fileTree(dir: 'libs', include: ['*.jar']) 
    testCompile 'junit:junit:4.12' 
    compile 'com.android.support:appcompat-v7:24.2.0' 
}

// Top-level build file where you can add configuration options common to all sub-projects/modules. 

buildscript { 
repositories { 
    jcenter() 
} 
dependencies { 
    classpath 'com.android.tools.build:gradle:2.1.3' 

    // NOTE: Do not place your application dependencies here; they belong 
    // in the individual module build.gradle files 
    } 
} 

allprojects { 
repositories { 
    jcenter() 
} 
} 

task clean(type: Delete) { 
delete rootProject.buildDir 
}

這是我第一次體驗。我做了幾個沒有任何錯誤的項目。我也試過重建和清潔。我在stackOverflow中嘗試了這些帖子。但是沒有用

Class not found error, but class definitely exists

Android app ClassNotFoundException for main activity

來源

2016-09-04 Pzy64

您是否嘗試從設備上卸載應用程序並進行清理，重建，然後重新安裝？ –

從所有xmls和java文件複製您的代碼，創建一個新項目並將代碼粘貼到其中。它應該工作。 – user6657161