找不到類異常Android應用程序（Android Studio）

Question

我已經看過有關此問題的其他問題，但是我找不到原因，為什么當我在真實設備上啟動我的應用程序時，它崩潰並得到ClassNotFoundException。 有沒有人有關於如何消除該錯誤的解決方案？ 注釋是否需要其他數據。 日志貓

    Caused by: java.lang.ClassNotFoundException: Didn't find class "com.example.trucktracker.MainActivity" on path: DexPathList[[zip file "/data/app/com.example.trucktracker-2.apk"],nativeLibraryDirectories=[/data/app-lib/com.example.trucktracker-2, /vendor/lib, /system/lib, /vendor/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.Instrumentation.newActivity(Instrumentation.java:1079)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2505)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2653)
            at android.app.ActivityThread.access$800(ActivityThread.java:156)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1355)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:157)
            at android.app.ActivityThread.main(ActivityThread.java:5872)
            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:852)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:668)
            at dalvik.system.NativeStart.main(Native Method)

爪哇

 package com.example.trucktracker;

import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.os.StrictMode;
import android.annotation.TargetApi;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Typeface;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.TextView;
import android.os.Build;

import com.example.trucktracker.Locator;

public class MainActivity extends ActionBarActivity
{
    protected TextView question;
    protected Button continuebtn;
    static String className;
    Spinner options;
    public void clickedContinue(View view)
    {
        Log.d(className, "ClickedContinueButton");
        Intent intent = new Intent(this, Locator.class);
        startActivity(intent);
    }
    @TargetApi(Build.VERSION_CODES.KITKAT) @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if (savedInstanceState == null)
        {
            getSupportFragmentManager().beginTransaction()
                    .add(R.id.container, new PlaceholderFragment())
                    .commit();

        }
        options = (Spinner) findViewById(R.id.optionselect);
        ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
                R.array.options, android.R.layout.simple_spinner_item);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        options.setAdapter(adapter);
        TextView refrigeratedtruck = (TextView) findViewById (R.id.question);
        Typeface typeFace=Typeface.createFromAsset(getAssets(),"Fonts/Roboto-Thin.ttf");
        refrigeratedtruck.setTypeface(typeFace);
        TextView temperature = (TextView) findViewById(R.id.tempquestion);
        temperature.setTypeface(typeFace);
    }

    public void  onItemSelected(AdapterView<?> options, View view,int position, long id)
    {
        TextView tempquestion1 = (TextView) findViewById(R.id.tempquestion);
        EditText temperaturein = (EditText) findViewById(R.id.tempin);
        if(position==0)
                {
            temperaturein.setVisibility(View.VISIBLE);
            tempquestion1.setVisibility(View.VISIBLE);
                }
        else
        {
            temperaturein.setVisibility(View.GONE);
            tempquestion1.setVisibility(View.GONE);
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu)
    {
        Log.d(className, "Showing menu.");
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;

    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item)
    {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    /**
     * A placeholder fragment containing a simple view.
     */
    public static class PlaceholderFragment extends Fragment
    {

        public PlaceholderFragment()
        {
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_main, container, false);
            return rootView;

        }
    }

}

表現

<?xml version="1.0" encoding="utf-8"?>
<manifest 
    xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.trucktracker"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="19" />

    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.CALL_PHONE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_PHONE_STATE" />

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

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name="com.example.trucktracker.Locator"
            android:label="@string/title_activity_locator" >
        </activity>
    </application>

</manifest>

Answer 1

好吧，你的道路似乎是正確的。 如果我沒記錯的話； 這可能是幻影錯誤，實際上並不存在。 嘗試清理項目/重新啟動Eclipse，然后在設備上進行測試。