SQLite数据库和ListView控件相关案例
界面管理数据库
运行界面
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
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
android
package 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
android
package 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>