运行效果

文件结构

主要代码

MainActivity

package cn.edu.sicnu.sqlitedemo;import android.content.ContentValues;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.CursorAdapter;import android.widget.EditText;import android.widget.ListView;import android.widget.SimpleCursorAdapter;public class MainActivity extends AppCompatActivity {    EditText editText_name,editText_age;    ListView listView;    //操作数据库游标适配器    SimpleCursorAdapter cursorAdapter;    SQLiteDatabase db;    MySQLHelper dbhelper;    Cursor cursor;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        editText_name = findViewById(R.id.editText_name);        editText_age = findViewById(R.id.editText_age);        listView = findViewById(R.id.listView);        dbhelper = new MySQLHelper(this,"lgy.db",null,1);        db = dbhelper.getWritableDatabase();//        cursor = db.rawQuery("select * from person",null);        cursor = db.query("person",null,null,null,null,null,null);        cursorAdapter = new SimpleCursorAdapter(this,android.R.layout.simple_list_item_2,cursor,new String[]{"name","age"},new int[]{android.R.id.text1,android.R.id.text2}, CursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER);        listView.setAdapter(cursorAdapter);    }    public void add(View view){//        db.execSQL("insert into person(name,age) values(?,?)",new Object[]{editText_name.getText().toString(),editText_age.getText().toString()});        ContentValues contentValues = new ContentValues();        contentValues.put("name",editText_name.getText().toString());        contentValues.put("age",editText_age.getText().toString());        db.insert("person",null,contentValues);        cursor = db.query("person",null,null,null,null,null,null);        cursorAdapter.swapCursor(cursor);        clearEdit();    }    public void delete(View view){//        db.execSQL("delete from person where name=?",new Object[]{editText_name.getText().toString()});        db.delete("person","name=?",new String[]{editText_name.getText().toString()});        cursor = db.query("person",null,null,null,null,null,null);        cursorAdapter.swapCursor(cursor);        clearEdit();    }    public void update(View view){//        db.execSQL("update person set age=? where name=?",new Object[]{editText_age.getText().toString(),editText_name.getText().toString()});        ContentValues contentValues = new ContentValues();        contentValues.put("age",editText_age.getText().toString());        db.update("person",contentValues,"name=?",new String[]{editText_name.getText().toString()});        cursor = db.query("person",null,null,null,null,null,null);        cursorAdapter.swapCursor(cursor);        clearEdit();    }    public void query(View view){        cursor = db.query("person",null,null,null,null,null,null);        cursorAdapter.swapCursor(cursor);    }    public void clearEdit(){        editText_name.setText("");        editText_age.setText("");        editText_name.requestFocus();    }}

MySQLHelper

package cn.edu.sicnu.sqlitedemo;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteOpenHelper;/** * Created by liguiyang on 2018/5/3. */public class MySQLHelper extends SQLiteOpenHelper {    public MySQLHelper(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {        super(context, name, factory, version);    }    @Override    public void onCreate(SQLiteDatabase db) {        db.execSQL("create table person(_id integer primary key autoincrement,name text,age integer)");    }    @Override    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {    }}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?><android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="cn.edu.sicnu.sqlitedemo.MainActivity">    <EditText        android:id="@+id/editText_name"        android:layout_width="0dp"        android:layout_height="wrap_content"        android:layout_marginBottom="1dp"        android:layout_marginEnd="16dp"        android:layout_marginStart="16dp"        android:layout_marginTop="3dp"        android:ems="10"        android:hint="Input your name?"        android:inputType="textPersonName"        app:layout_constraintBottom_toTopOf="@+id/editText_age"        app:layout_constraintEnd_toEndOf="parent"        app:layout_constraintStart_toStartOf="parent"        app:layout_constraintTop_toTopOf="parent" />    <EditText        android:id="@+id/editText_age"        android:layout_width="353dp"        android:layout_height="wrap_content"        android:ems="10"        android:hint="Input your age?"        android:inputType="number"        app:layout_constraintBottom_toTopOf="@+id/button"        app:layout_constraintEnd_toEndOf="@+id/button2"        app:layout_constraintStart_toEndOf="@+id/button2"        app:layout_constraintTop_toBottomOf="@+id/editText_name" />    <Button        android:id="@+id/button"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginBottom="8dp"        android:onClick="add"        android:text="add"        app:layout_constraintBottom_toTopOf="@+id/listView"        app:layout_constraintEnd_toStartOf="@+id/button2"        app:layout_constraintHorizontal_chainStyle="packed"        app:layout_constraintStart_toStartOf="parent"        app:layout_constraintTop_toBottomOf="@+id/editText_age" />    <Button        android:id="@+id/button2"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:onClick="delete"        android:text="delete"        app:layout_constraintBottom_toBottomOf="@+id/button"        app:layout_constraintEnd_toStartOf="@+id/button3"        app:layout_constraintStart_toEndOf="@+id/button" />    <Button        android:id="@+id/button3"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:onClick="update"        android:text="update"        app:layout_constraintBottom_toBottomOf="@+id/button2"        app:layout_constraintEnd_toStartOf="@+id/button4"        app:layout_constraintStart_toEndOf="@+id/button2" />    <Button        android:id="@+id/button4"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:onClick="query"        android:text="query"        app:layout_constraintBottom_toBottomOf="@+id/button3"        app:layout_constraintEnd_toEndOf="parent"        app:layout_constraintStart_toEndOf="@+id/button3" />    <ListView        android:id="@+id/listView"        android:layout_width="368dp"        android:layout_height="0dp"        android:layout_marginBottom="8dp"        app:layout_constraintBottom_toBottomOf="parent"        app:layout_constraintEnd_toEndOf="@+id/button2"        app:layout_constraintStart_toEndOf="@+id/button2"        app:layout_constraintTop_toBottomOf="@+id/button" />android.support.constraint.ConstraintLayout>

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