getWritableDatabase 无法解析

Question

我正在关注一个关于如何为 android 应用程序制作 sqlite 数据库的 youtube 视频，但我遇到了这个问题：

mSQLiteDb =  mMyHelper.getWritableDatabase();

在这一行它说getWritableDatabase() 无法解决

谁能帮我解决这个问题？

MainActivity.java

package com.example.sqlitedb;

import android.database.sqlite.SQLiteDatabase;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;

public class MainActivity extends AppCompatActivity {

private EditText mNameEt;
private EditText mPhoneEt;
private Object mMyHelper;
private SQLiteDatabase mSQLiteDb;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mNameEt = (EditText)findViewById(R.id.editText);
    mPhoneEt = (EditText)findViewById(R.id.editText2);
    mMyHelper = new MyHelper(MainActivity.this,"STUDDB",null,1);
    mSQLiteDb =  mMyHelper.getWritableDatabase();
}

public void insertData(View view) {

}

public void readData(View view) {
}
}

MyHelper.java

package com.example.sqlitedb;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class MyHelper extends SQLiteOpenHelper {
public MyHelper(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {
    super(context, name, factory, version);
}

@Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {
    sqLiteDatabase.execSQL("create table student(_id integer primary key, name text, phone text)");
}

@Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {

}
}

谢谢

Answer 1

替换：

private Object mMyHelper;

与：

private MyHelper mMyHelper;