SQLite数据库操作详解-优快云博客

本文链接：https://blog.youkuaiyun.com/Wandering_sea/article/details/102557864

@[toc] 10.14作业

sqlite

package com.example.day1014_homework.SQLBean;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.support.annotation.Nullable;

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

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL("create table user (id integer primary key autoincrement , name varchar(20),address varchar(30))");

        db.beginTransaction();

        for (int i = 0; i < 100; i++) {
            db.execSQL("insert into user values (null,'张三','北京')");
        }
        db.setTransactionSuccessful();
        db.endTransaction();

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    }
}

package com.example.day1014_homework;

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.Toast;

import com.example.day1014_homework.SQLBean.MySqlHelper;

public class MainActivity extends AppCompatActivity {

    private MySqlHelper sqlHelper;
    private SQLiteDatabase database;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        sqlHelper = new MySqlHelper(this, "User.db", null, 1);

        database = sqlHelper.getReadableDatabase();


    }

    //添加数据
    public void insert(View view) {
        //原生
        String sql = "insert into user values (?,?,?)";
        database.execSQL(sql, new Object[]{null, "李四", "南京"});

        //自带的
        ContentValues values = new ContentValues();
        values.put("name", "王五");
        values.put("address", "赵六");

        database.insert("user", null, values);


    }

    //更新数据
    public void update(View view) {
       //原生
        String sql = "update user set address = ? where id = ?";
        database.execSQL(sql, new Object[]{"上海", 1});

        //自带
        ContentValues values = new ContentValues();
        values.put("address", "天津");
        database.update("user", values, "id = ?", new String[]{"2"});

    }

    //查询数据
    public void search(View view) {
        //原生
        String sql = "select * from user";
        Cursor cursor = database.rawQuery(sql, new String[]{});
        if(cursor != null){
            while (cursor.moveToNext()){
                int id = cursor.getInt(cursor.getColumnIndex("id"));
                String name = cursor.getString(cursor.getColumnIndex("name"));
                String address = cursor.getString(cursor.getColumnIndex("address"));
                Toast.makeText(this, id+"+"+name+"+"+address+"+"+1, Toast.LENGTH_SHORT).show();
            }
        }else {
            Toast.makeText(this, "空", Toast.LENGTH_SHORT).show();
        }

        //自带

        Cursor user = database.query("user", null, null, null, null, null, null);
        if(user != null){
            while (user.moveToNext()){
                int id = user.getInt(user.getColumnIndex("id"));
                String name = user.getString(user.getColumnIndex("name"));
                String address = user.getString(user.getColumnIndex("address"));
                Toast.makeText(this, id+"+"+name+"+"+address, Toast.LENGTH_SHORT).show();
            }
        }else {
            Toast.makeText(this, "空", Toast.LENGTH_SHORT).show();
        }

    }

    //删除数据
    public void delete(View view) {
        //原生
        String sql = "delete from user where id = ?";
        database.execSQL(sql,new Object[]{3});


        //自带
        database.delete("user","id = ?",new String[]{"4"});
    }
}

引导页

activity

package com.example.app2;

import android.content.Intent;
import android.os.Handler;
import android.os.Message;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;

import com.example.app2.fragment.Wel_Fragment;

import java.util.ArrayList;
import java.util.List;
import java.util.Timer;
import java.util.TimerTask;

public class MainActivity extends AppCompatActivity {

    private ViewPager viewPager;
    private List<Fragment> lists = new ArrayList<>();
    private List<ImageView> imageViewList = new ArrayList<>();
    private TextView textView;
    private Button button;
    private Timer timer ;
    private LinearLayout linearLayout;
    private Timer timer_change ;
    private int index = 0;
    private int flag = 5;

    Handler handler = new Handler(){
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            if(msg.what == 100){
                viewPager.setCurrentItem(index);
                index++;
                if(index == lists.size()){
                    index = 0;
                    timer.cancel();
                    timerget();
                }
            }else if(msg.what == 101){
                flag--;
                textView.setText("倒计时："+flag+"秒");

                if(flag == 0){
                    Intent intent = new Intent(MainActivity.this,Main2Activity.class);
                    startActivity(intent);
                    timer_change.cancel();
                    finish();
                }
            }
        }
    };

    private void timerget() {
        timer_change = new Timer();
        timer_change.schedule(new TimerTask() {
            @Override
            public void run() {
                handler.sendEmptyMessage(101);
            }
        },0,1000);
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        viewPager = findViewById(R.id.viewpageer);
        textView = findViewById(R.id.text_title);
        button = findViewById(R.id.button);
        linearLayout = findViewById(R.id.linear);




        for (int i = 0; i < 3; i++) {
            Wel_Fragment fragment = new Wel_Fragment();
            ImageView imageView = new ImageView(this);
            imageView.setImageResource(R.drawable.circle_gary);
            linearLayout.addView(imageView);
            imageViewList.add(imageView);
            lists.add(fragment);
        }
        viewPager.setAdapter(new FragmentStatePagerAdapter(getSupportFragmentManager()) {
            @Override
            public Fragment getItem(int i) {
                return lists.get(i);
            }

            @Override
            public int getCount() {
                return lists.size();
            }
        });
        viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int i, float v, int i1) {

            }

            @Override
            public void onPageSelected(int i) {
                if(i == 2){
                    textView.setVisibility(View.VISIBLE);
                    button.setVisibility(View.VISIBLE);
                }else {
                    textView.setVisibility(View.GONE);
                    button.setVisibility(View.GONE);
                }


                for (int i1 = 0; i1 < lists.size(); i1++) {
                    if(i == 0){
                        imageViewList.get(0).setImageResource(R.drawable.circle);
                    }else {
                        imageViewList.get(i1).setImageResource(R.drawable.circle_gary);
                    }
                    if(i == i1){
                        imageViewList.get(i1).setImageResource(R.drawable.circle);
                    }else {
                        imageViewList.get(i1).setImageResource(R.drawable.circle_gary);
                    }

                }
            }

            @Override
            public void onPageScrollStateChanged(int i) {

            }
        });

        timer = new Timer();
        timer.schedule(new TimerTask() {
            @Override
            public void run() {
                handler.sendEmptyMessage(100);
            }
        },0,1000);






    }

    public void click(View view) {
        Intent intent = new Intent(MainActivity.this,Main2Activity.class);
        startActivity(intent);
        timer_change.cancel();
        finish();
    }
}

fragment (引导页和后面公用一个fragment)

package com.example.app2.fragment;


import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import com.example.app2.R;

/**
 * A simple {@link Fragment} subclass.
 */
public class Wel_Fragment extends Fragment {


    public Wel_Fragment() {
        // Required empty public constructor
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View inflate = inflater.inflate(R.layout.fragment_wel_, container, false);
        TextView textView = inflate.findViewById(R.id.wel_Tv);
        Bundle bundle = getArguments();
        if(bundle != null){
            String msg = bundle.getString("msg");
            textView.setText(msg);
        }
        return inflate;
    }

}

fragment 和 TabLayout 联动


package com.example.app2;

import android.support.annotation.Nullable;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import com.example.app2.fragment.Wel_Fragment;

import java.util.ArrayList;
import java.util.List;

public class Main2Activity extends AppCompatActivity {

    private TabLayout tabl;
    private ViewPager viewPager;
    private List<Fragment> list_fm = new ArrayList<>();
    private List<String> stringList = new ArrayList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);


        tabl = (TabLayout) findViewById(R.id.tabl);
        viewPager = (ViewPager) findViewById(R.id.view_pager);

        for (int i = 0; i < 3; i++) {
            Wel_Fragment fragment = new Wel_Fragment();
            Bundle bundle = new Bundle();
            bundle.putString("msg","这是第"+i+"个fragment");
            fragment.setArguments(bundle);
            stringList.add("第"+i+"个");
            list_fm.add(fragment);
        }

        tabl.setupWithViewPager(viewPager);
        viewPager.setAdapter(new FragmentStatePagerAdapter(getSupportFragmentManager()) {
            @Override
            public Fragment getItem(int i) {
                return list_fm.get(i);
            }

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

            @Nullable
            @Override
            public CharSequence getPageTitle(int position) {
                return stringList.get(position);
            }
        });

    }
}