android listview综合使用示例_结合数据库操作和listitem单击长按等事件处理

本示例说明:

1.自定义listview条目样式,自定义listview显示列数的多少,灵活与数据库中字段绑定.

2.实现对DB的增删改查,并且操作后listview自动刷新.

3.响应用户操作点击事件,示例中展示单击时取出主键Id和其他内容.

4.响应用户操作长按事件,示例中展示长按时根据主键Id来编辑和删除数据.

5.表现层与数据处理层分开,不依赖于cursor(使用cursor不易表现和业务分离),支持接口编程.

6.使用数据库处理框架AHibernate灵活操作sqlite数据库,详见: http://blog.csdn.net/lk_blog/article/details/7455992

 

本示例效果图:

list.xml:

<?xml version="1.0" encoding="UTF-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/child"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="#E3D25E"
    android:orientation="horizontal" >

    <!-- 若想隐藏id加入此属性: android:visibility="gone",这样做有点类似于Html中hidden域 -->

    <TextView
        android:id="@+id/idTo"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="#ff0000" />

    <TextView
        android:id="@+id/nameTo"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:paddingBottom="5px"
        android:paddingLeft="50px"
        android:paddingTop="5px"
        android:text="No data"
        android:textColor="#0000ff"
        android:textSize="20sp" />

    <TextView
        android:id="@+id/ageTo"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:paddingBottom="5px"
        android:paddingLeft="50px"
        android:paddingTop="5px"
        android:text="No data"
        android:textColor="#00ff00"
        android:textSize="20sp" />

</LinearLayout>

2.MainActivity.java:

package com.tgb.lk.listview;

import java.util.List;
import java.util.Map;

import com.tgb.lk.demo.dao.StudentDao;
import com.tgb.lk.demo.dao.impl.StudentDaoImpl;
import com.tgb.lk.demo.model.Student;

import com.tgb.lk.listview.R;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.ContextMenu;
import android.view.MenuItem;
import android.view.View;
import android.view.ContextMenu.ContextMenuInfo;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.AdapterView.AdapterContextMenuInfo;
import android.widget.AdapterView.OnItemClickListener;
/**
 * 欢迎访问我的博客进行对代码交流: http://blog.csdn.net/lk_blog
 * 数据库处理使用AHibernate框架,详见:http://blog.csdn.net/lk_blog/article/details/7455992
 * @author likun
 */
public class MainActivity extends Activity {
    private static final int ITEM_MODIFY = 1;
    private static final int ITEM_DELETE = 2;

    // 定义接口
    private StudentDao dao = null;
    private ListView lv = null;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        // 添加
        Button btnAdd = (Button) findViewById(R.id.btnAdd);
        btnAdd.setOnClickListener(listener);
        // 显示前3条数据
        Button btnShow = (Button) findViewById(R.id.btnShow);
        btnShow.setOnClickListener(listener);
        // 删除数据
        Button btnClear = (Button) findViewById(R.id.btnClear);
        btnClear.setOnClickListener(listener);

        lv = (ListView) findViewById(R.id.lvStudent);
        // 设置在条目上单击监听器
        lv.setOnItemClickListener(itemListener);
        // 设置长按事件
        registerForContextMenu(lv);

        // 显示所有数据
        showData(-1);
    }

    // 显示数据,num小于等于0时显示所有数据,num大于0时显示前N条.
    private void showData(int num) {
        dao = (dao == null ? new StudentDaoImpl(this) : dao);
        List<Map<String, String>> data = null;
        if (num <= 0) { // 显示所有学生,调用dao层接口
            data = dao.queryAllStudent();
        } else {// 显示前N个学生,调用dao层接口
            data = dao.queryTopN(num);
        }
        SimpleAdapter adapter = buildListAdapter(this, data);
        lv.setAdapter(adapter);

    }

    // 构建adapter.
    public SimpleAdapter buildListAdapter(Context context,
            List<Map<String, String>> data) {
        SimpleAdapter adapter = new SimpleAdapter(context, data, R.layout.list,
                new String[] { "_id", "name", "age" }, new int[] { R.id.idTo,
                        R.id.nameTo, R.id.ageTo });
        return adapter;
    }

    // 初始化数据
    OnClickListener listener = new OnClickListener() {
        @Override
        public void onClick(View v) {
            dao = (dao == null ? new StudentDaoImpl(MainActivity.this) : dao);
            switch (v.getId()) {
            case R.id.btnAdd:
                // 添加学生
                Student student1 = new Student();
                student1.setName("lk");
                student1.setAge(26);
                dao.insert(student1);

                Student student2 = new Student();
                student2.setName("cls");
                student2.setAge(26);
                dao.insert(student2);

                Student student3 = new Student();
                student3.setName("lb");
                student3.setAge(27);
                dao.insert(student3);
                showData(-1);

                break;
            case R.id.btnShow:
                // 显示前3条数据
                showData(3);
                break;
            case R.id.btnClear:
                // 删除所有数据
                dao.deleteData();

                // 显示所有数据
                showData(-1);
                break;
            default:
                break;
            }

        }
    };

    // 条目上单击处理方法.
    OnItemClickListener itemListener = new OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position,
                long id) {
            // 这里的view是我们在list.xml中定义的LinearLayout对象.
            // 所以可以通过findViewById方法可以找到list.xml中定义的它的子对象,如下:
            TextView stuId = (TextView) view.findViewById(R.id.idTo);
            TextView stuName = (TextView) view.findViewById(R.id.nameTo);
            TextView stuAge = (TextView) view.findViewById(R.id.ageTo);

            toastShow("学号:" + stuId.getText().toString() + "; 姓名:"
                    + stuName.getText().toString() + "; 年龄:"
                    + stuAge.getText().toString());
        }
    };

    // 封装Toast,一方面调用简单,另一方面调整显示时间只要改此一个地方即可.
    public void toastShow(String text) {
        Toast.makeText(MainActivity.this, text, 1000).show();
    }

    // 长按时显示的菜单
    @Override
    public void onCreateContextMenu(ContextMenu menu, View v,
            ContextMenuInfo menuInfo) {
        menu.setHeaderTitle("请选择操作");
        menu.add(0, ITEM_MODIFY, 0, "编辑");
        menu.add(0, ITEM_DELETE, 1, "删除");
    }

    // 响应编辑和删除事件处理
    public boolean onContextItemSelected(MenuItem item) {
        AdapterContextMenuInfo info = (AdapterContextMenuInfo) item
                .getMenuInfo();
        // info.targetView得到list.xml中的LinearLayout对象.
        String stuId = ((TextView) info.targetView.findViewById(R.id.idTo))
                .getText().toString();
        if (!TextUtils.isEmpty(stuId)) {
            int id = Integer.parseInt(stuId);
            dao = (dao == null ? new StudentDaoImpl(this) : dao);
            switch (item.getItemId()) {
            case ITEM_MODIFY:
                // 编辑数据
                toastShow("编辑" + stuId);
                // 此方法定义在AHibernate中.更多使用示例见http://blog.csdn.net/lk_blog/article/details/7455992
                Student student = dao.get(id);
                student.setName("李坤");
                student.setAge(26);
                dao.update(student); // 此方法定义在AHibernate中.
                break;
            case ITEM_DELETE:
                // 删除数据
                toastShow("删除" + stuId);
                dao.delete(id);// 此方法定义在AHibernate中.
                break;
            default:
                break;
            }
        }
        showData(-1);
        return false;
    }

}

3.数据库处理层:StudentDaoImpl.java:

package com.tgb.lk.demo.dao.impl;

import java.util.List;
import java.util.Map;

import com.tgb.lk.ahibernate.dao.impl.BaseDaoImpl;
import com.tgb.lk.demo.dao.StudentDao;
import com.tgb.lk.demo.model.Student;
import com.tgb.lk.demo.util.DBHelper;
import android.content.Context;

//本文数据库处理引用jar包AHibernate处理.
//AHibernate的详细使用教程示例地址: http://blog.csdn.net/lk_blog/article/details/7455992
//AHibernate源码交流地址: http://blog.csdn.net/lk_blog/article/details/7456125
//AHibernate jar包下载及源代码下载地址: http://download.csdn.net/detail/lk_blog/4222048
public class StudentDaoImpl extends BaseDaoImpl<Student> implements StudentDao {
    public StudentDaoImpl(Context context) {
        super(new DBHelper(context));
    }

    // 返回一个List,List中的对象是以sql中的列的小写形式为key的Map.(本例中 _id,name,age为key)
    public List<Map<String, String>> queryAllStudent() {
        String sql = "select _id, name,age from t_student";
        return super.query2MapList(sql, null);
    }

    // 返回一个List,List中的对象是以sql中的列的小写形式为key的Map.(本例中 _id,name,age为key)
    public List<Map<String, String>> queryTopN(int num) {
        String sql = "select _id, name,age from t_student limit ?";
        return super.query2MapList(sql, new String[] { String.valueOf(num) });
    }

    public void deleteData() {
        String sql = "delete from t_student";
        super.execSql(sql, null);
    }
}

本示例源代码下载地址:  http://download.csdn.net/detail/lk_blog/4278055

文章转载于 http://blog.csdn.net/lk_blog/article/details/7537200