android - java.lang.RuntimeException : Unable to instantiate activity ComponentInfo/is not accessible from class 错误

Question

我正在尝试运行一个应用程序，但当我选择一个菜单项时，该应用程序立即停止工作，并且出现以下错误:

logcat:
     03-23 19:54:11.029: E/AndroidRuntime(1316): FATAL EXCEPTION: main
03-23 19:54:11.029: E/AndroidRuntime(1316): Process: com.example.testcalnd2, PID: 1316
03-23 19:54:11.029: E/AndroidRuntime(1316): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.testcalnd2/com.example.testcalnd2.ActivityDiaryEdit}: java.lang.IllegalAccessException: class com.example.testcalnd2.ActivityDiaryEdit is not accessible from class android.app.Instrumentation
03-23 19:54:11.029: E/AndroidRuntime(1316):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2236)
03-23 19:54:11.029: E/AndroidRuntime(1316):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2390)
03-23 19:54:11.029: E/AndroidRuntime(1316):     at android.app.ActivityThread.access$800(ActivityThread.java:151)
03-23 19:54:11.029: E/AndroidRuntime(1316):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
03-23 19:54:11.029: E/AndroidRuntime(1316):     at android.os.Handler.dispatchMessage(Handler.java:102)
03-23 19:54:11.029: E/AndroidRuntime(1316):     at android.os.Looper.loop(Looper.java:135)
03-23 19:54:11.029: E/AndroidRuntime(1316):     at android.app.ActivityThread.main(ActivityThread.java:5257)
03-23 19:54:11.029: E/AndroidRuntime(1316):     at java.lang.reflect.Method.invoke(Native Method)
03-23 19:54:11.029: E/AndroidRuntime(1316):     at java.lang.reflect.Method.invoke(Method.java:372)
03-23 19:54:11.029: E/AndroidRuntime(1316):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
03-23 19:54:11.029: E/AndroidRuntime(1316):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
03-23 19:54:11.029: E/AndroidRuntime(1316): Caused by: java.lang.IllegalAccessException: class com.example.testcalnd2.ActivityDiaryEdit is not accessible from class android.app.Instrumentation
03-23 19:54:11.029: E/AndroidRuntime(1316):     at java.lang.Class.newInstance(Class.java:1591)
03-23 19:54:11.029: E/AndroidRuntime(1316):     at android.app.Instrumentation.newActivity(Instrumentation.java:1066)
03-23 19:54:11.029: E/AndroidRuntime(1316):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2226)
03-23 19:54:11.029: E/AndroidRuntime(1316):     ... 10 more
03-23 19:54:20.399: I/Process(1316): Sending signal. PID: 1316 SIG: 9

MainActivity 类:

package com.example.testcalnd2;

import android.app.Activity;
import android.app.ListActivity;
import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.support.v4.widget.SimpleCursorAdapter;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ListView;

public class MainActivity extends ListActivity {
      private static final int ACTIVITY_CREATE = 0;
      private static final int ACTIVITY_EDIT = 1;

      private static final int INSERT_ID = Menu.FIRST;
      private static final int DELETE_ID = Menu.FIRST + 1;

      private DiaryDbAdapter mDbHelper;
      private Cursor mDiaryCursor;

      @Override
      public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.diary_list);
        mDbHelper = new DiaryDbAdapter(this);
        mDbHelper.open();
        renderListView();

      }

      private void renderListView() {
        mDiaryCursor = mDbHelper.getAllNotes();
        startManagingCursor(mDiaryCursor);
        String[] from = new String[] { DiaryDbAdapter.KEY_TITLE,
            DiaryDbAdapter.KEY_CREATED };
        int[] to = new int[] { R.id.text1, R.id.created };
        SimpleCursorAdapter notes = new SimpleCursorAdapter(this,
            R.layout.diary_now, mDiaryCursor, from, to);
        setListAdapter(notes);
      }

      @Override
      public boolean onCreateOptionsMenu(Menu menu) {
        super.onCreateOptionsMenu(menu);
        menu.add(0, INSERT_ID, 0, R.string.menu_insert);
        menu.add(0, DELETE_ID, 0, R.string.menu_delete);
       return true;
     }

      @Override
      public boolean onMenuItemSelected(int featureId, MenuItem item) {
        switch (item.getItemId()) {
        case INSERT_ID:
          createDiary();
          return true;
        case DELETE_ID:
          mDbHelper.deleteDiary(getListView().getSelectedItemId());
          renderListView();
          return true;
        }
        return super.onMenuItemSelected(featureId, item);
      }

      private void createDiary() {
        Intent i = new Intent(this, ActivityDiaryEdit.class);
        startActivityForResult(i, ACTIVITY_CREATE);
      }

      @Override

      protected void onListItemClick(ListView l, View v, int position, long id) {
        super.onListItemClick(l, v, position, id);
        Cursor c = mDiaryCursor;
        c.moveToPosition(position);
        Intent i = new Intent(this, ActivityDiaryEdit.class);
        i.putExtra(DiaryDbAdapter.KEY_ROWID, id);
        i.putExtra(DiaryDbAdapter.KEY_TITLE, c.getString(c
            .getColumnIndexOrThrow(DiaryDbAdapter.KEY_TITLE)));
        i.putExtra(DiaryDbAdapter.KEY_BODY, c.getString(c
            .getColumnIndexOrThrow(DiaryDbAdapter.KEY_BODY)));
        startActivityForResult(i, ACTIVITY_EDIT);
      }

      @Override
      protected void onActivityResult(int requestCode, int resultCode,
          Intent intent) {
        super.onActivityResult(requestCode, resultCode, intent);
        renderListView();
      }
    }


package com.example.testcalnd2;

import android.app.ListActivity;
import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;

DiaryDbAdapter:

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

import java.util.Calendar;
import java.util.Date;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

 class DiaryDbAdapter {

  public static final String KEY_TITLE = "title";
  public static final String KEY_BODY = "body";
  public static final String KEY_ROWID = "_id";
  public static final String KEY_CREATED = "created";

  private static final String TAG = "DiaryDbAdapter";
  private DatabaseHelper mDbHelper;
  private SQLiteDatabase mDb;

  private static final String DATABASE_CREATE = "create table diary (_id integer primary key autoincrement, "
      + "title text not null, body text not null, created text not null);";

  private static final String DATABASE_NAME = "database";
  private static final String DATABASE_TABLE = "diary";
  private static final int DATABASE_VERSION = 1;

  private final Context mCtx;

  private static class DatabaseHelper extends SQLiteOpenHelper {

    DatabaseHelper(Context context) {
      super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
      db.execSQL(DATABASE_CREATE);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
      db.execSQL("DROP TABLE IF EXISTS diary");
      onCreate(db);
    }
  }

  public DiaryDbAdapter(Context ctx) {
    this.mCtx = ctx;
  }

  public DiaryDbAdapter open() throws SQLException {
    mDbHelper = new DatabaseHelper(mCtx);
    mDb = mDbHelper.getWritableDatabase();
    return this;
  }

  public void closeclose() {
    mDbHelper.close();
  }

  public long createDiary(String title, String body) {
    ContentValues initialValues = new ContentValues();
    initialValues.put(KEY_TITLE, title);
    initialValues.put(KEY_BODY, body);
    Calendar calendar = Calendar.getInstance();
    String created = calendar.get(Calendar.YEAR) + ""
        + calendar.get(Calendar.MONTH) + ""
        + calendar.get(Calendar.DAY_OF_MONTH) + ""
        + calendar.get(Calendar.HOUR_OF_DAY) + ""
        + calendar.get(Calendar.MINUTE) + "";
    initialValues.put(KEY_CREATED, created);
    return mDb.insert(DATABASE_TABLE, null, initialValues);
  }

  public boolean deleteDiary(long rowId) {

    return mDb.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0;
  }

  public Cursor getAllNotes() {

    return mDb.query(DATABASE_TABLE, new String[] { KEY_ROWID, KEY_TITLE,
        KEY_BODY, KEY_CREATED }, null, null, null, null, null);
  }

  public Cursor getDiary(long rowId) throws SQLException {

    Cursor mCursor =

    mDb.query(true, DATABASE_TABLE, new String[] { KEY_ROWID, KEY_TITLE,
        KEY_BODY, KEY_CREATED }, KEY_ROWID + "=" + rowId, null, null,
        null, null, null);
    if (mCursor != null) {
      mCursor.moveToFirst();
    }
    return mCursor;

  }

  public boolean updateDiary(long rowId, String title, String body) {
    ContentValues args = new ContentValues();
    args.put(KEY_TITLE, title);
    args.put(KEY_BODY, body);
    Calendar calendar = Calendar.getInstance();
    String created = calendar.get(Calendar.YEAR) + ""
        + calendar.get(Calendar.MONTH) + ""
        + calendar.get(Calendar.DAY_OF_MONTH) + ""
        + calendar.get(Calendar.HOUR_OF_DAY) + ""
        + calendar.get(Calendar.MINUTE) + "";
    args.put(KEY_CREATED, created);

    return mDb.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId, null) > 0;
  }
}

ActivityDiaryEdit Activity :

 class ActivityDiaryEdit extends Activity {

  private EditText mTitleText;
  private EditText mBodyText;
  private Long mRowId;
  private DiaryDbAdapter mDbHelper;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    mDbHelper = new DiaryDbAdapter(this);
    mDbHelper.open();
    setContentView(R.layout.diary_edit);

    mTitleText = (EditText) findViewById(R.id.title);
    mBodyText = (EditText) findViewById(R.id.body);

    Button confirmButton = (Button) findViewById(R.id.confirm);

    mRowId = null;
    Bundle extras = getIntent().getExtras();
    if (extras != null) {
      String title = extras.getString(DiaryDbAdapter.KEY_TITLE);
      String body = extras.getString(DiaryDbAdapter.KEY_BODY);
      mRowId = extras.getLong(DiaryDbAdapter.KEY_ROWID);

      if (title != null) {
        mTitleText.setText(title);
      }
      if (body != null) {
        mBodyText.setText(body);
      }
    }

    confirmButton.setOnClickListener(new View.OnClickListener() {
      public void onClick(View view) {
        String title = mTitleText.getText().toString();
        String body = mBodyText.getText().toString();
        if (mRowId != null) {
          mDbHelper.updateDiary(mRowId, title, body);
        } else
          mDbHelper.createDiary(title, body);
        Intent mIntent = new Intent();
        setResult(RESULT_OK, mIntent);
        finish();
      }

    });
  }
}

list :

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.testcalnd2"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="14"
        android:targetSdkVersion="22" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".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=".DiaryDbAdapter"
            android:label="@string/title_activity_diary_db_adapter" >
        </activity>
        <activity
                android:name="com.example.testcalnd2.ActivityDiaryEdit">

</activity>

    </application>

</manifest>

Answer 1

像这样公开你的类ActivityDiaryEdit:

public class ActivityDiaryEdit extends Activity {
    ...

希望这对您有所帮助!