Android实战简易教程-第二十四枪（基于Baas的用户表查询功能实现！）

接着上一篇，我们注册了几个用户，用户表如下：

下面我们用ListView将表中数据显示出来吧！

首先看一下main.xml：

<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" >

    <Button
        android:id="@+id/btn_query"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="查询所有用户" />

    <ListView
        android:id="@+id/lv_users"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@+id/btn_query" >
    </ListView>

</RelativeLayout>

然后MainActivity.java:

package com.example.listviewdemo;

import java.util.List;

import cn.bmob.v3.Bmob;
import cn.bmob.v3.BmobQuery;
import cn.bmob.v3.listener.FindListener;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;

public class MainActivity extends Activity {
  private Button mButtonQuery;
  private ListView mListViewUsers;
  private ListViewAdapter adapter;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Bmob.initialize(this, "8f3ffb2658d8a3366a70a0b0ca0b71b2");// 初始化Bmob
    mButtonQuery = (Button) findViewById(R.id.btn_query);
    mListViewUsers = (ListView) findViewById(R.id.lv_users);

    mButtonQuery.setOnClickListener(new OnClickListenerImpl());

  }

  private class OnClickListenerImpl implements OnClickListener {

    @Override
    public void onClick(View v) {
      BmobQuery<User> query = new BmobQuery<User>();// 查询类
      query.findObjects(MainActivity.this, new FindListener<User>() {

        @Override
        public void onSuccess(List<User> list) {

          adapter = new ListViewAdapter(MainActivity.this, list);// 实例化
          mListViewUsers.setAdapter(adapter);
        }

        @Override
        public void one rror(int arg0, String arg1) {
          Toast.makeText(MainActivity.this, "查询失败！", 3).show();
        }
      });
    }

  }

}

ListViewAdapter.java:

package com.example.listviewdemo;

import java.util.List;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

public class ListViewAdapter extends BaseAdapter {
  private Context context;
  private List<User> list;
  private LayoutInflater inflater;

  public ListViewAdapter(Context context, List<User> list) {
    this.context = context;
    this.list = list;
    inflater = LayoutInflater.from(context);

  }

  @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(int position, View convertView, ViewGroup parent) {
    ViewHolder viewHolder = null;
    if (convertView == null) {
      viewHolder = new ViewHolder();
      convertView = inflater.inflate(R.layout.listview_item, null);
      viewHolder.tv_idTextView = (TextView) convertView
          .findViewById(R.id.tv_id);
      viewHolder.tv_usernameTextView = (TextView) convertView
          .findViewById(R.id.tv_username);
      viewHolder.tv_userPasswordTextView = (TextView) convertView
          .findViewById(R.id.tv_userpassword);
      viewHolder.tv_timeTextView = (TextView) convertView
          .findViewById(R.id.tv_time);
      convertView.setTag(viewHolder);
    } else {
      viewHolder = (ViewHolder) convertView.getTag();
    }
    viewHolder.tv_idTextView
        .setText(list.get(position).getObjectId() + "|");
    viewHolder.tv_usernameTextView.setText(list.get(position).getUserName()
        + "|");
    viewHolder.tv_userPasswordTextView.setText(list.get(position)
        .getUserPassword() + "|");
    viewHolder.tv_timeTextView.setText(list.get(position).getCreatedAt());
    return convertView;
  }

  class ViewHolder {
    private TextView tv_idTextView;
    private TextView tv_usernameTextView;
    private TextView tv_userPasswordTextView;
    private TextView tv_timeTextView;
  }

}

list_item.xml:

<?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="match_parent"
    android:orientation="horizontal" >

    <TextView
        android:id="@+id/tv_id"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/tv_username"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/tv_userpassword"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/tv_time"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

User.java:

package com.example.logintest;

import cn.bmob.v3.BmobObject;

public class User extends BmobObject {
  private String userPassword;
  public String getUserPassword() {
    return userPassword;
  }
  public void setUserPassword(String userPassword) {
    this.userPassword = userPassword;
  }
  public String getUserName() {
    return userName;
  }
  public void setUserName(String userName) {
    this.userName = userName;
  }
  private String userName;
}

最后配置文件：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.listviewdemo"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.READ_PHONE_STATE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_LOGS" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.listviewdemo.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

看一下文件：

运行实例：

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