使用Android實現接口信息的留言版顯示


      關於這個篇日志,我上周末的時候已經寫好了初稿,但是后來電腦安裝程序的時候,出了問題重裝了。結果沒有備份好,這個星期也在忙着學習新的知識,也就把發表的事情擱置了。今天看到,一些同學上交了作業,都沒有使用老師指定的接口實現。那么,我來分享一下,我的一點點成果。

     看到標題,顧名思義,我今天只是和大家講一下如何實現接口信息的顯示,不包括添加信息。

     接口幫助文檔:http://api.wzhospital.cn/msg/help  

     根據查看接口文檔,我們可以知道接口內部的一些信息結構。

     當然,想要查看具體的信息,是通過此鏈接:http://api.wzhospital.cn/MSG/api/Message/GetList 

     獲取以下信息,來驗證顯示的正確性。

<Messages xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.datacontract.org/2004/07/LYB.Models">

<Data>

<Message>

<Content>我的第一個默認留言</Content>

<CreateTime>2015-07-30 08:29:19</CreateTime>

<Messager>林豪</Messager>

<MessagerAge>22</MessagerAge>

<MessagerSex>女</MessagerSex>

<Receiver>林志玲</Receiver>

</Message>

<Message>

<Content>我的第二個默認留言</Content>

<CreateTime>2015-07-30 08:31:19</CreateTime>

<Messager>林志玲</Messager>

<MessagerAge>18</MessagerAge>

<MessagerSex>女</MessagerSex>

<Receiver>劉德華</Receiver>

</Message>

<Message>

<Content>

我的第三個默認留言我的第三個默認留言我的第三個默認留言我的第三個默認留言我的第三個默認留言我的第三個默認留言我的第三個默認留言我的第三個默認留言我的第三個默認留言我的第三個默認留言我的第三個默認留言

</Content>

<CreateTime>2015-07-30 08:33:19</CreateTime>

<Messager>林豪</Messager>

<MessagerAge>22</MessagerAge>

<MessagerSex>人妖</MessagerSex>

<Receiver>林志玲</Receiver>

</Message>

<Message>

<Content>dd</Content>

<CreateTime>2015-07-30 16:35:57</CreateTime>

<Messager>h</Messager>

<MessagerAge>0</MessagerAge>

<MessagerSex>nn</MessagerSex>

<Receiver>mm</Receiver>

</Message>

<Message>

<Content>content</Content>

<CreateTime>2015-07-30 16:37:49</CreateTime>

<Messager>me</Messager>

<MessagerAge>18</MessagerAge>

<MessagerSex>male</MessagerSex>

<Receiver>you</Receiver>

</Message>

<Message>

<Content>12</Content>

<CreateTime>2015-07-30 16:52:42</CreateTime>

<Messager>sk</Messager>

<MessagerAge>0</MessagerAge>

<MessagerSex>le</MessagerSex>

<Receiver>kd</Receiver>

</Message>

<Message>

<Content>content</Content>

<CreateTime>2015-07-30 17:05:32</CreateTime>

<Messager>me</Messager>

<MessagerAge>0</MessagerAge>

<MessagerSex>youe</MessagerSex>

<Receiver>dddd</Receiver>

</Message>

</Data>

</Messages>

首先,我先給大家看一下界面效果圖(排版難看,大家諒解)。

            1xiaoguo                     222

第一步:先說一下,整個頁面是布局。

           這個頁面由兩部分組成,其一:activity_main.xml中,只包含一個listView.其二:重寫了一個list_message.xml.

                                listview                                                     chongxielistview

                                            activity_main.xml                                                                                                   list_message.xml

            關於為什么重寫一個.xml文件呢,這是因為listview本身比較復雜,重寫一個便於引用顯示。

第二步:根據接口文檔,建立實體類。

               wen

                單擊 GET api/Message/GetList 將獲得接口信息,由於我采用的是json的格式,我只截取這一段代碼。

                         json

                     根據信息分析,我創建了一個message.java的實體類。

package com.example.message.model;

import android.R.string;

public class Message {
    private String content;
    private String creatime;
    private String messager;
    private String messagerAge;
    private String messagerSex;
    private String reciver;
   
    public String getContent() {
        return content;
    }
   
    public void setContent(String content){
        this.content=content;
    }
   
    public String getCreatime() {
        return creatime;
    }
    public void setCreatime(String creatime) {
        this.creatime=creatime;
    }
   
    public String getMessager() {
        return messager;
    }
   
    public void setMessager(String messager) {
        this.messager=messager;
    }
   
    public String getMessagerAge() {
        return messagerAge;
    }
   
    public void setMessagerAge(String messagerAge) {
        this.messagerAge=messagerAge;
    }
   
    public String getMessagerSex() {
        return messagerSex;
    }
    public void setMessagerSex(String messagerSex) {
        this.messagerSex=messagerSex;
    }
   
    public String getReceiver() {
        return reciver;
    }
   
    public void setReceiver(String reciver) {
        this.reciver=reciver;
    }
   
    public String tostring() {
        return "content:"+content+",creatime:"+creatime+",Messager:"+messager+",MessagerAge:"+messagerAge+",MessagerSex:"+messagerSex+",Reciver:"+reciver;
    }
}

      第三步:我們需要做的是如何獲取接口的數據,並且去解析(我將其寫於MainActivity.java中)它,那么我們需要新建一個新類,這個我取名為HttpData.java。它的作用就是獲取接口中的內容。代碼如下

package com.example.message;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.params.HttpParams;

public class HttpData {

    private HttpClient client;//定義HTTP一個客戶端
    private HttpResponse reponse;//定義一個HTTP響應
    private HttpEntity entity;//定義一個HTTP實體
   
    private InputStream in;//定義一個輸入流
    private BufferedReader reader;//定義一個字符流;
   
    private StringBuffer data = new StringBuffer("");//定義一個空的字符串緩沖;
   
    private String url = "http://api.wzhospital.cn/MSG/api/Message/GetList";
    //private String url1="http://api.wzhospital.cn/MSG/api/Message/Add";
    private HttpGet get;//GET:請求的數據隨HTTP請求頭發過去
   
    public StringBuffer getData(){//此方法獲取接口的文本內容,並以字符流的形式return
        client = new DefaultHttpClient();
        get = new HttpGet(url);//url定向
       
        try {
            HttpParams params = new HttpParams() {
               
                public HttpParams setParameter(String arg0, Object arg1) {
                    // TODO Auto-generated method stub
                    return null;
                }
               
                public HttpParams setLongParameter(String arg0, long arg1) {
                    // TODO Auto-generated method stub
                    return null;
                }
               
                public HttpParams setIntParameter(String arg0, int arg1) {
                    // TODO Auto-generated method stub
                    return null;
                }
               
                public HttpParams setDoubleParameter(String arg0, double arg1) {
                    // TODO Auto-generated method stub
                    return null;
                }
               
                public HttpParams setBooleanParameter(String arg0, boolean arg1) {
                    // TODO Auto-generated method stub
                    return null;
                }
               
                public boolean removeParameter(String arg0) {
                    // TODO Auto-generated method stub
                    return false;
                }
               
                public boolean isParameterTrue(String arg0) {
                    // TODO Auto-generated method stub
                    return false;
                }
               
                public boolean isParameterFalse(String arg0) {
                    // TODO Auto-generated method stub
                    return false;
                }
               
                public Object getParameter(String arg0) {
                    // TODO Auto-generated method stub
                    return null;
                }
               
                public long getLongParameter(String arg0, long arg1) {
                    // TODO Auto-generated method stub
                    return 0;
                }
               
                public int getIntParameter(String arg0, int arg1) {
                    // TODO Auto-generated method stub
                    return 0;
                }
               
                public double getDoubleParameter(String arg0, double arg1) {
                    // TODO Auto-generated method stub
                    return 0;
                }
               
                public boolean getBooleanParameter(String arg0, boolean arg1) {
                    // TODO Auto-generated method stub
                    return false;
                }
               
                public HttpParams copy() {
                    // TODO Auto-generated method stub
                    return null;
                }
            };
           
            reponse = client.execute(get);//執行客戶端的get操作
            entity = reponse.getEntity();//獲取響應中是實例
            in = entity.getContent();//獲取實例中的文本內容
            reader = new BufferedReader(new InputStreamReader(in));//讀入字符流
            String line = "";
            while( (line = reader.readLine()) != null ){
                data.append(line);
            }
            return data;
           
        } catch (ClientProtocolException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
       
        return data;   
    }
}

第四步:封裝數據集合(listview),通過視圖繪制,此處采用的是數據適配器繪制。代碼如下:

package com.example.message;

import java.util.List;
import java.util.zip.Inflater;

import com.example.message.model.Message;

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

public class DataAdapter extends BaseAdapter{

    private List<Message> messages;
    private Context context;
   
    private TextView v_content;
    private TextView v_time;
    private TextView v_messger;
    private TextView v_messgerAge;
    private TextView v_messgerSex;
    private TextView v_receiver;
   
    public DataAdapter(List<Message> messages, Context context){
        this.messages = messages;
        this.context = context;
    }
   
    public int getCount() {
        return messages.size();
    }

    public Object getItem(int arg0) {
        return messages.get(arg0);
    }

    public long getItemId(int arg0) {
        // TODO Auto-generated method stub
        return arg0;
    }

    public View getView(int arg0, View arg1, ViewGroup arg2) {

        RelativeLayout layout = (RelativeLayout)LayoutInflater.from(context).inflate(R.layout.list_message, null);
        Message msg = (Message)getItem(arg0);
       
       
        v_content = (TextView)layout.findViewById(R.id.Content);
        v_time = (TextView)layout.findViewById(R.id.CreateTime);
        v_messger = (TextView)layout.findViewById(R.id.Meassger);
        v_receiver = (TextView)layout.findViewById(R.id.Receiver);
        v_messgerAge=(TextView)layout.findViewById(R.id.MessagerAge);
        v_messgerSex=(TextView)layout.findViewById(R.id.MessagerSex);
       
       
        v_content.setText(msg.getContent());
        v_time.setText(msg.getCreatime());
        v_messger.setText(msg.getMessager());
        v_receiver.setText(msg.getReceiver());
        v_messgerAge.setText(msg.getMessagerAge());
        v_messgerSex.setText(msg.getMessagerSex());
       
        return layout;
    }

}
第五步:我們來看一看MainActivity.java是如何調用方法獲取數據,並解析的。此處額外新開了一個子線程,進行操作。代碼如下:

package com.example.message;

import android.os.Bundle;
import android.os.Handler;
import android.app.Activity;
import android.view.Menu;

import java.io.FileOutputStream; 
import java.io.InputStream; 
import java.util.ArrayList;
import java.util.List; 

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
 
import android.app.Activity; 
import android.content.Context; 
import android.os.Bundle; 
import android.util.Log; 
import android.view.View; 
import android.widget.Button; 
import android.widget.ListView;
 
import com.example.message.model.Message; 

public class MainActivity extends Activity {
   
    private List<Message> messages = new ArrayList<Message>(); 
    private DataAdapter myAdapter;  //定義一個自己的適配器,用於繪制
    private Handler handler;//定義一個Handler,Handler 負責在必要時進行信息格式化
    private ListView listView;
    
    public void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.activity_main); 
        listView = (ListView)findViewById(R.id.listView);
       
        handler = new Handler() {
           
            public void handleMessage(android.os.Message msg) {
                if(msg.what == 0x123){
                    System.out.println("接收數據");
                    for(Message g:messages){
                        System.out.println(g.getContent());
                    }
                    myAdapter = new DataAdapter(messages, MainActivity.this);
                    listView.setAdapter(myAdapter);
                }
            };
           
        };
        new Thread(new Runnable() {
           
            public void run() {
                // TODO Auto-generated method stub
                HttpData data = new HttpData();
                StringBuffer str = data.getData();
                System.out.println(str.toString());
                Log.v("msg", str.toString());
                try {
                    JSONObject object = new JSONObject(str.toString());//使用json ,解析數據
                    JSONArray msg = (JSONArray)object.get("Data");
                    for(int i=0; i<msg.length(); i++){
                        JSONObject o = msg.getJSONObject(i);
                        Message message = new Message();
                        message.setContent(o.getString("Content"));
                        message.setCreatime(o.getString("CreateTime"));
                        message.setMessager(o.getString("Messager"));
                        message.setMessagerAge(o.getString("MessagerAge"));
                        message.setMessagerSex(o.getString("MessagerSex"));
                        message.setReceiver(o.getString("Receiver"));
                        messages.add(message);
                    }
                    android.os.Message handlerMsg = new android.os.Message();
                    handlerMsg.what = 0x123;
                    handler.sendMessage(handlerMsg);
                    System.out.println("發送數據");
                } catch (JSONException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }).start();
      
    }

}

以上,就是實現接口留言板的顯示。有以下幾點,是在我寫的時候遇到的問題。

1、個別電腦的虛擬機和電腦設置的問題,程序可能跑不起來,建議使用安卓真機。

2、由於我們的程序存在網絡訪問,需要在網絡訪問配置文件當中加寫權限設置。

3、有關網絡方面的東西,都必須寫在子線程上,這就是為什么我重新開了一個新的線程。

4、控件的更新必須在主線程上,否則將出錯。

5、當我們使用適配器繪制時,其中getCount這個方法必須要寫。

 

以上就是本文的全部內容,這是本人第一次寫博客,不喜勿噴。歡迎指教。微笑


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