Android高级-Android操作SQL数据管理，增删改查

　　已经学了好几天SQL了，昨天刚接触到Android操作SQL数据库，作了一个小demo，效果图如下

分别是，主界面，和修改，添加，以及删除界面

首先我们先来实现布局 MainActivity.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"

    tools:context="wuxianedu.com.sqllistview.MainActivity">

    <ListView android:id="@+id/lv_liebiao"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
    </ListView>
</RelativeLayout>

布局很简洁，只有一个ListView,

下面是List列表的item布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal" android:layout_width="match_parent"
    android:layout_height="match_parent">
    <LinearLayout   android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="5">
    <TextView android:id="@+id/tv_name"
        android:layout_width="0dp" android:layout_gravity="center_vertical"
        android:layout_height="wrap_content"
        android:text="aaa" android:layout_weight="1"
        android:gravity="center"/>

    <TextView android:id="@+id/tv_age"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" android:layout_gravity="center_vertical"
        android:text="aaa" android:layout_weight="1"
        android:gravity="center"/>
    <TextView android:id="@+id/tv_sex"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" android:layout_gravity="center_vertical"
        android:text="aaa" android:layout_weight="1"
        android:gravity="center"/>
    </LinearLayout>
    <Button android:id="@+id/but_name"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="修改" android:layout_weight="1"
        android:gravity="center"/>

    <Button android:id="@+id/but_delete"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="删除" android:layout_weight="1"
        android:gravity="center"/>
</LinearLayout>

之后是修改和添加界面的XML代码

UpdateActivity.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:orientation="vertical"
    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="wuxianedu.com.sqllistview.UpdateActivity">

    <EditText android:id="@+id/ed_name"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入姓名"/>

    <EditText android:id="@+id/ed_age"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入年龄"
        android:layout_below="@+id/ed_name"/>

    <EditText android:id="@+id/ed_sex"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入性别"
        android:layout_below="@+id/ed_age"/>

    <Button android:id="@+id/but_queding"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:hint="修改用户"
        android:layout_below="@+id/ed_sex"/>

    <Button android:id="@+id/but_tianjia"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="添加用户"
        android:layout_below="@+id/ed_sex"/>


</RelativeLayout >

　　这里要说一下，添加数据和修改数据用的是一个布局，在JAva文件中通过判断来确定是修改还是添加，

　　下面贴出JAVA代码

package wuxianedu.com.sqllistview;

import android.content.ContentValues;
import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ListView;

import java.util.List;

import wuxianedu.com.sqllistview.DB.DBauxiliary;

public class MainActivity extends AppCompatActivity {

    private MainAdapter mainAdapter;//构建数据源
    private List list;//接收数据的LIST
    private DBauxiliary db;//数据库操作类的实例

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ListView listView = (ListView) findViewById(R.id.lv_liebiao);
        db = DBauxiliary.getInstance(this);
         list= db.select();
        //构建数据源
        mainAdapter = new MainAdapter(this,list);
        //添加数据
        listView.setAdapter(mainAdapter);
    }
    //Activity创建或者从被覆盖、后台重新回到前台时被调用  
    @Override
    protected void onResume() {
        super.onResume();
        //重新获取list数据
        list = db.select();
        //给list赋值 更新
        mainAdapter.setList(list);
    }

    @Override //菜单的点击事件
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu,menu);
        menu.findItem(R.id.add).setOnMenuItemClickListener(new MenuItem.OnMenuItemClickListener() {
            @Override
            public boolean onMenuItemClick(MenuItem item) {
                //点击添加跳转
                Intent intent=new  Intent(MainActivity.this,UpdateActivity.class);
                startActivityForResult(intent,5);
                return false;
            }
        });
        return super.onCreateOptionsMenu(menu);

    }
}

MainAdapter.java
此文件用来填充Adapter数据

package wuxianedu.com.sqllistview;

import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.support.v7.app.AlertDialog;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import java.util.List;

import wuxianedu.com.sqllistview.DB.DBauxiliary;

/**
 * Created by Administrator on 2016/9/20.
 */
public class MainAdapter extends BaseAdapter {
    private Context context;
    private List<JavaBean> list;//接收数据的LIST
    private DBauxiliary db;//数据库操作类的实例
    //适配器
    public MainAdapter(Context context,List<JavaBean> list){
        this.context = context;
        this.list = list;
    }
    //更新集合用
    public void setList(List<JavaBean> list) {
        this.list = list;
        notifyDataSetChanged();
    }

    @Override
    public int getCount() {
        return list.size();
    }

    @Override
    public Object getItem(int position) {
        return list.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
       final HUi hui;
        if(convertView == null){
            hui = new HUi();
            final int wo ;
            wo = position;
            db = DBauxiliary.getInstance(context);
            convertView = LayoutInflater.from(context).inflate(R.layout.item_lie, null);
            hui.name = (TextView) convertView.findViewById(R.id.tv_name);
            hui.age = (TextView) convertView.findViewById(R.id.tv_age);
            hui.sex = (TextView) convertView.findViewById(R.id.tv_sex);
            hui.update = (Button) convertView.findViewById(R.id.but_name);
            hui.delete = (Button) convertView.findViewById(R.id.but_delete);

            //
            //修改按钮
            hui.update.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Intent intent = new Intent(context,UpdateActivity.class);
                    int on = (int) hui.update.getTag();
                    JavaBean javabean = list.get(on);
                    intent.putExtra("name",javabean);
                    context.startActivity(intent);

                }
            });
            convertView.setTag(hui);
        }else{
            hui = (HUi) convertView.getTag();
        }

        final JavaBean java = list.get(position);
        hui.update.setTag(position);
        hui.name.setText(java.getName());
        hui.age.setText(String.valueOf(java.getAge()));
        hui.sex.setText(java.getSex());
        final String naaa = java.getName();
        //构建删除对话框
        hui.delete.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                AlertDialog.Builder builder = new  AlertDialog.Builder(context);
                builder.setMessage("确定删除吗？");
                builder.setPositiveButton("取消",null);
                builder.setNegativeButton("确定", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        db.delete(naaa);
                        list = db.select();
                        setList(list);
                        notifyDataSetChanged();
                        Toast.makeText(context,"删除成功",Toast.LENGTH_SHORT).show();
                    }
                }).show();

            }
        });
        return convertView;
    }

    class HUi {
        TextView name,age,sex;
        Button update,delete;
    }
}

UpdateActivity.java
用于添加和修改数据

package wuxianedu.com.sqllistview;

import android.content.ContentValues;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import wuxianedu.com.sqllistview.DB.DBauxiliary;

public class UpdateActivity extends AppCompatActivity implements View.OnClickListener {

    private DBauxiliary db;
    private EditText ed_name,ed_sex,ed_age;
    private JavaBean com;
    private Button xiugai,shanchu;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_update);
        ed_name= (EditText) findViewById(R.id.ed_name);
        ed_age = (EditText) findViewById(R.id.ed_age);
        ed_sex = (EditText) findViewById(R.id.ed_sex);
        xiugai = (Button) findViewById(R.id.but_tianjia);
        shanchu = (Button) findViewById(R.id.but_queding);
        Intent on = getIntent();
         com = (JavaBean) on.getSerializableExtra("name");
        if(com == null){
            shanchu.setVisibility(View.GONE);
        }else{
            xiugai.setVisibility(View.GONE);
            ed_name.setText(com.getName()+"");
            ed_age.setText(String.valueOf(com.getAge())+"");
            ed_sex.setText(com.getSex()+"");
        }
        db = DBauxiliary.getInstance(UpdateActivity.this);
/*        ed_name.setText(com.getName()+"");
        ed_age.setText(String.valueOf(com.getAge())+"");
        ed_sex.setText(com.getSex()+"");*/
        xiugai.setOnClickListener(this);
        shanchu.setOnClickListener(this);

    }
    private void SqlInsert(){
        ContentValues contentValues = new ContentValues();
        contentValues.put("name",ed_name.getText().toString());
        contentValues.put("age",ed_age.getText().toString());
        contentValues.put("sex",ed_sex.getText().toString());
        db.insert(contentValues);
        Toast.makeText(UpdateActivity.this,"添加成功",Toast.LENGTH_SHORT).show();
    }
    //删除数据
    private void SqlUpdate(){
        ContentValues contentValues = new ContentValues();
        contentValues.put("name",ed_name.getText().toString());
        contentValues.put("age",ed_age.getText().toString());
        contentValues.put("sex",ed_sex.getText().toString());
        db.update(contentValues,com.getName());
        Toast.makeText(UpdateActivity.this,"修改成功",Toast.LENGTH_SHORT).show();
    }
    //判断
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
            if(requestCode != 5){

            }
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.but_queding:
                SqlUpdate();
                break;
            case R.id.but_tianjia:
                SqlInsert();
                break;
        }
    }
}

到这里所有功能就都写完了，我都写上注释了，如果有不明白的也可以留言，也可以加我Q,1171628833，本人刚安卓，小白一个，有同是小白的可以一起交流，共同成长，其他有一个Menu菜单，我没有写，因为不太明白，