在空白的Android活动上找不到类错误 [英] Class not found errors on blank Android Activity

问题描述

当我在Android Studio 2.0中创建空白活动并尝试在API 16上运行该活动时，它将正确编译.当我在具有API 23的仿真器上运行它时，它运行无误.当我在API 16上运行它时，在应用启动时会给我很多错误.见下文.奇怪的是，该应用程序运行正常.

When I create a blank activity in Android Studio 2.0 and try to run it on API 16 it compiles without errors. When I run it on an emulator with API 23 it runs without errors. When I run it on API 16 it gives me a bunch of errors when the app starts. See below. The weird thing is that the app runs OK.

这可能是什么原因?

在Android Studio中，我无效并清除了缓存.还清理了项目并重建了它.

In Android Studio I invalidated and cleared the cache. Also cleaned the project and rebuilt it.

代码以供参考:

AndroidManifest.xml

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

MainActivity.Java

package nl.myapp.test;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

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

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="nl.myapp.test.MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!" />
</RelativeLayout>

2.0.0版构建文件build.gradle(模块应用程序)

apply plugin: 'com.android.application'

android {
    compileSdkVersion 23
    buildToolsVersion "23.0.3"

    defaultConfig {
        applicationId "nl.myapp.test"
        minSdkVersion 16
        targetSdkVersion 23
        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-v7:23.3.0'
}

该应用在API 16上启动时的logcat错误

04-10 18:29:29.945 23899-23899/nl.myapp.test E/dalvikvm: Could not find class 'android.app.ActivityManager$TaskDescription', referenced from method nl.myapp.test.MainActivity.access$super
04-10 18:29:29.945 23899-23899/nl.myapp.test E/dalvikvm: Could not find class 'android.os.UserHandle', referenced from method nl.myapp.test.MainActivity.access$super
04-10 18:29:29.945 23899-23899/nl.myapp.test E/dalvikvm: Could not find class 'android.os.UserHandle', referenced from method nl.myapp.test.MainActivity.access$super
04-10 18:29:29.945 23899-23899/nl.myapp.test E/dalvikvm: Could not find class 'android.app.SharedElementCallback', referenced from method nl.myapp.test.MainActivity.access$super
04-10 18:29:29.945 23899-23899/nl.myapp.test E/dalvikvm: Could not find class 'android.os.PersistableBundle', referenced from method nl.myapp.test.MainActivity.access$super
04-10 18:29:29.945 23899-23899/nl.myapp.test E/dalvikvm: Could not find class 'android.transition.TransitionManager', referenced from method nl.myapp.test.MainActivity.access$super
04-10 18:29:29.945 23899-23899/nl.myapp.test E/dalvikvm: Could not find class 'android.app.SharedElementCallback', referenced from method nl.myapp.test.MainActivity.access$super
04-10 18:29:29.945 23899-23899/nl.myapp.test E/dalvikvm: Could not find class 'android.os.UserHandle', referenced from method nl.myapp.test.MainActivity.access$super
04-10 18:29:29.945 23899-23899/nl.myapp.test E/dalvikvm: Could not find class 'android.os.UserHandle', referenced from method nl.myapp.test.MainActivity.access$super
04-10 18:29:29.945 23899-23899/nl.myapp.test E/dalvikvm: Could not find class 'android.app.assist.AssistContent', referenced from method nl.myapp.test.MainActivity.access$super
04-10 18:29:29.945 23899-23899/nl.myapp.test E/dalvikvm: Could not find class 'android.view.SearchEvent', referenced from method nl.myapp.test.MainActivity.access$super
04-10 18:29:29.945 23899-23899/nl.myapp.test E/dalvikvm: Could not find class 'android.os.UserHandle', referenced from method nl.myapp.test.MainActivity.access$super
04-10 18:29:29.945 23899-23899/nl.myapp.test E/dalvikvm: Could not find class 'android.os.PersistableBundle', referenced from method nl.myapp.test.MainActivity.access$super

推荐答案

在Android Studio中，我转到了文件->项目结构->项目.

In Android Studio I went to File -> Project Structure -> Project.

首先，我将Gradle升级到 2.11 ，并将Android插件版本升级到 2.0.0 . 接下来，我同步了项目并对其进行了编译.错误仍然存​​在.

First I upgraded Gradle to 2.11 and the Android Plugin Version to 2.0.0. Next I synced the project and compiled it. The errors were still there.

此后，我将Android插件版本降级为 1.5.0 .

After this I downgraded the Android Plugin Version to 1.5.0.

现在，当我编译并运行项目时，错误消失了.

Now when I compile and run the project the errors are gone.

这篇关于在空白的Android活动上找不到类错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！