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  • 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,我们注冊了几个用户,用户表例如以下:


    以下我们用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="查询全部用户" />
    
        <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 onError(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:


    执行实例:


    喜欢的朋友关注我,谢谢!


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  • 原文地址:https://www.cnblogs.com/llguanli/p/6945902.html
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