Android实战简易教程<二十四>（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：

[html] view
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<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:

[java] view
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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 onError(int arg0, String arg1) {

Toast.makeText(MainActivity.this, "查询失败！", 3).show();

}

});

}



}



}

ListViewAdapter.java:

[java] view
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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:

[html] view
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<?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:

[java] view
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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：

[html] view
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<?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：