SQLite数据库和ListView控件相关案例

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 界面管理数据库

运行界面

这里写图片描述

 要实现这个功能要监听删除按钮的点击事件 监听对话框的确认按钮点击事件 ListView的Item设置点击监听事件

这里写图片描述

单击向上箭头会给相应数据的金额+1实现这个功能要在BaseAdapter的 getView() 方法中监听该图片的点击事件

界面交互代码

MainActivity

ListView 的 setOnItemClickListener() 方法

用于监听Item的点击事件使用时需要传入一个OnItemClickListener 实现类对象且需要实现onItemClick() 方法

ListView 的 setSelection() 方法

设置当前选中的条目

package product.itcast.cn.productshow;import android.accounts.Account;import android.content.DialogInterface;import android.net.Uri;import android.support.v7.app.AlertDialog;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.view.ViewGroup;import android.widget.AdapterView;import android.widget.BaseAdapter;import android.widget.EditText;import android.widget.ImageView;import android.widget.ListView;import android.widget.TextView;import android.widget.Toast;import com.google.android.gms.appindexing.Action;import com.google.android.gms.appindexing.AppIndex;import com.google.android.gms.appindexing.Thing;import com.google.android.gms.common.api.GoogleApiClient;import java.util.List;import product.itcast.cn.productshow.dao.AccountDao;public class MainActivity extends AppCompatActivity {    private List<product.itcast.cn.productshow.bean.Account> list;    private AccountDao dao;    private EditText nameET;    private EditText balanceET;    private MyAdapter adapter;    private ListView accountLV;    /**     * ATTENTION: This was auto-generated to implement the App Indexing API.     * See https://g.co/AppIndexing/AndroidStudio for more information.     */    private GoogleApiClient client;    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initView();        dao = new AccountDao(this);        list = dao.queryAll();        adapter = new MyAdapter();        accountLV.setAdapter(adapter);        // ATTENTION: This was auto-generated to implement the App Indexing API.        // See https://g.co/AppIndexing/AndroidStudio for more information.        client = new GoogleApiClient.Builder(this).addApi(AppIndex.API).build();    }    private void initView() {        accountLV = (ListView) findViewById(R.id.accountLV);        nameET = (EditText) findViewById(R.id.nameET);        balanceET = (EditText) findViewById(R.id.balanceET);        accountLV.setOnItemClickListener(new MyOnItemClickListener());    }    public void add(View v) {        String name = nameET.getText().toString().trim();        String balance = balanceET.getText().toString().trim();        product.itcast.cn.productshow.bean.Account a = new product.itcast.cn.productshow.bean.Account(name, balance.equals("") ? 0                : Integer.parseInt(balance));        dao.insert(a);        list.add(a);        adapter.notifyDataSetChanged();        accountLV.setSelection(accountLV.getCount() - 1);        nameET.setText("");        balanceET.setText("");    }    /**     * ATTENTION: This was auto-generated to implement the App Indexing API.     * See https://g.co/AppIndexing/AndroidStudio for more information.     */    public Action getIndexApiAction() {        Thing object = new Thing.Builder()                .setName("Main Page") // TODO: Define a title for the content shown.                // TODO: Make sure this auto-generated URL is correct.                .setUrl(Uri.parse("http://[ENTER-YOUR-URL-HERE]"))                .build();        return new Action.Builder(Action.TYPE_VIEW)                .setObject(object)                .setActionStatus(Action.STATUS_TYPE_COMPLETED)                .build();    }    @Override    public void onStart() {        super.onStart();        // ATTENTION: This was auto-generated to implement the App Indexing API.        // See https://g.co/AppIndexing/AndroidStudio for more information.        client.connect();        AppIndex.AppIndexApi.start(client, getIndexApiAction());    }    @Override    public void onStop() {        super.onStop();        // ATTENTION: This was auto-generated to implement the App Indexing API.        // See https://g.co/AppIndexing/AndroidStudio for more information.        AppIndex.AppIndexApi.end(client, getIndexApiAction());        client.disconnect();    }    private class MyAdapter extends BaseAdapter {        public int getCount() {            return list.size();        }        public Object getItem(int position) {            return list.get(position);        }        public long getItemId(int position) {            return position;        }        public View getView(int position, View convertView, ViewGroup parent) {            View item = convertView != null ? convertView : View.inflate(getApplicationContext(), R.layout.item, null);            TextView idTV = (TextView) item.findViewById(R.id.idTV);            TextView nameTV = (TextView) item.findViewById(R.id.nameTV);            TextView balanceTV = (TextView) item.findViewById(R.id.balanceTV);            //final Account a = list.get(position);            final product.itcast.cn.productshow.bean.Account a = list.get(position);            //idTV.setText(a.getId + "");            idTV.setText(a.getId()+"");            nameTV.setText(a.getName());            balanceTV.setText(a.getBalance() + "");            ImageView upIV = (ImageView) item.findViewById(R.id.upIV);            ImageView downIV = (ImageView) item.findViewById(R.id.downIV);            ImageView deleteIV = (ImageView) item.findViewById(R.id.deleteIV);            upIV.setOnClickListener(new View.OnClickListener() {                public void onClick(View v) {                    a.setBalance(a.getBalance() + 1);                    notifyDataSetChanged();                    dao.update(a);                }            });            downIV.setOnClickListener(new View.OnClickListener() {                public void onClick(View v) {                    a.setBalance(a.getBalance() - 1);                    notifyDataSetChanged();                    dao.update(a);                }            });            deleteIV.setOnClickListener(new View.OnClickListener() {                public void onClick(View v) {                    DialogInterface.OnClickListener listener = new DialogInterface.OnClickListener() {                        public void onClick(DialogInterface dialog, int which) {                            list.remove(a);                            dao.delete(a.getId());                            notifyDataSetChanged();                        }                    };                    AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);                    builder.setTitle("确定要删除么?");                    builder.setPositiveButton("确定", listener);                    builder.setNegativeButton("取消", null);                    builder.show();                }            });            return item;        }    }    private class MyOnItemClickListener implements AdapterView.OnItemClickListener {        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {            Account a = (Account) parent.getItemAtPosition(position);            Toast.makeText(getApplicationContext(), a.toString(), Toast.LENGTH_SHORT).show();        }    }}

Account类

package product.itcast.cn.productshow.bean;/** * Created by Administrator on 2017/4/17. */public class Account {    private Long id;    private String name;    private Integer balance;    public Long getId(){        return id;    }    public void setId(Long id){        this.id = id;    }    public String getName(){        return name;    }    public void setName(String name){        this.name = name;    }    public Integer getBalance(){        return balance;    }    public void setBalance(Integer balance){        this.balance = balance;    }    public Account (Long id, String name, Integer balance){        super();        this.id = id;        this.name = name;        this.balance = balance;    }    public Account(String name, Integer balance){        super();        this.name = name;        this.balance = balance;    }    public Account(){        super();    }    public String toString(){        return "[序号:"+id+",商品名称:"+name+", 余额:"+balance+"]";    }}

AccountDao类

用于操作数据

androidpackage product.itcast.cn.productshow.dao;import android.content.ContentValues;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import java.util.ArrayList;import java.util.List;import product.itcast.cn.productshow.bean.Account;/** * Created by Administrator on 2017/4/17. */public class AccountDao {    private MyHelper helper;    public AccountDao(Context context) {        helper = new MyHelper(context);    }    public void insert(Account account) {        SQLiteDatabase db = helper.getWritableDatabase();        ContentValues values = new ContentValues();        values.put("name", account.getName());        values.put("balance", account.getBalance());        long id = db.insert("account", null, values);        account.setId(id);        db.close();    }    public int delete(long id) {        SQLiteDatabase db = helper.getWritableDatabase();        int count = db.delete("account", "_id=?", new String[]{id + ""});        db.close();        return count;    }    public int update(Account account) {        SQLiteDatabase db = helper.getWritableDatabase();        ContentValues values = new ContentValues();        values.put("name", account.getName());        values.put("balance", account.getBalance());        int count = db.update("account", values, "_id=?", new String[]{account.getId() + ""});        db.close();        return count;    }    public List<Account> queryAll() {        SQLiteDatabase db = helper.getReadableDatabase();        Cursor c = db.query("account", null, null, null, null, null, "balance DESC");        List<Account> list = new ArrayList<Account>();        while (c.moveToNext()) {            long id = c.getLong(c.getColumnIndex("_id"));            String name = c.getString(1);            int balance = c.getInt(2);            list.add(new Account(id, name, balance));        }        c.close();        db.close();        return list;    }}

MyHelper类

androidpackage product.itcast.cn.productshow.dao;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteOpenHelper;/** * Created by Administrator on 2017/4/17. */public class MyHelper extends SQLiteOpenHelper {    public MyHelper (Context context) {        super(context,"itcast.db",null,2);    }    public  void onCreate(SQLiteDatabase db) {        System.out.println("onCreate");        db.execSQL("CREATE TABLE account(_id INTEGER PRIMARY KEY AUTOINCREMENT,name VARCHAR(20),balance INTEGER)");    }    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {        System.out.println("onUpgrade");    }}

布局文件

Activity_main.xml

android<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:id="@+id/activity_main"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:layout_margin="8dp"    android:orientation="vertical"    tools:context="product.itcast.cn.productshow.MainActivity">    <LinearLayout        android:id="@+id/addLL"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:orientation="horizontal">        <EditText            android:id="@+id/nameET"            android:layout_width="0dp"            android:layout_height="wrap_content"            android:layout_weight="1"            android:hint="商品展示"            android:inputType="textPersonName" />        <EditText            android:id="@+id/balanceET"            android:layout_width="0dp"            android:layout_height="wrap_content"            android:layout_weight="1"            android:hint="金额"            android:inputType="number" />        <ImageView            android:id="@+id/addIV"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:onClick="add"            android:src="@android:drawable/ic_input_add" />    </LinearLayout>    <ListView        android:id="@+id/accountLV"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:layout_below="@id/addLL"></ListView></LinearLayout>

item.xml

TextView用于显示数据库中的某条数据的详细信息
ImageView用于增加减少金额和删除金额

android<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:orientation="horizontal"    android:padding="10dp">    <TextView        android:id="@+id/idTV"        android:layout_width="0dp"        android:layout_height="wrap_content"        android:layout_weight="1"        android:text="13"        android:textColor="#000000"        android:textSize="20sp"/>    <TextView        android:id="@+id/nameTV"        android:layout_width="0dp"        android:layout_height="wrap_content"        android:layout_weight="2"        android:singleLine="true"        android:text="PQ"        android:textColor="#000000"        android:textSize="20sp"/>    <LinearLayout        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:orientation="vertical">        <ImageView            android:id="@+id/upIV"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_marginBottom="2dp"            android:src="@android:drawable/arrow_up_float"/>        <ImageView            android:id="@+id/downIV"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:src="@android:drawable/arrow_down_float"/>    </LinearLayout>    <TextView        android:id="@+id/balanceTV"        android:layout_width="0dp"        android:layout_height="wrap_content"        android:layout_weight="2"        android:singleLine="true"        android:text="12345"        android:textColor="#000000"        android:textSize="20sp"/>    <ImageView        android:id="@+id/deleteIV"        android:layout_width="25dp"        android:layout_height="25dp"        android:src="@android:drawable/ic_menu_delete"/></LinearLayout>

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