點擊條目跳轉

package com.example.day02;

import android.annotation.SuppressLint;
import android.content.Intent;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.Toast;

import com.google.gson.Gson;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    private ListView listview;
    private List<Lei.NewslistBean> list;
    @SuppressLint("HandlerLeak")
    private Handler mhan=new Handler(){
        @Override
        public void handleMessage(Message msg) {
            final List<Lei.NewslistBean> list=(List<Lei.NewslistBean>)msg.obj;
           Ba ba= new Ba(list,MainActivity.this);
            listview.setAdapter(ba);
            listview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                @Override
                public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                    String pic=list.get(i).getPicUrl();
                    if(pic!=null&&pic.length()>0){
                        Intent intent = new Intent(MainActivity.this,Main2Activity.class);
                        intent.putExtra("picdata",pic);
                        startActivity(intent);
                    }else{

                        Toast.makeText(MainActivity.this,"沒有圖片",Toast.LENGTH_SHORT).show();
                    }
                }
            });
        }
    };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        listview = findViewById(R.id.listview);
        new Thread(){
            @Override
            public void run() {
                NexData();
            }
        }.start();



    }

    private void NexData() {
        try {
            URL url=new URL("http://api.tianapi.com/social/?key=af3b2b7acbfd7c08a4c60dbe16674c0b&num=10");
            HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
            urlConnection.setRequestMethod("GET");
            urlConnection.setReadTimeout(5000);
            urlConnection.setConnectTimeout(5000);
            int responseCode = urlConnection.getResponseCode();
            if(responseCode==200){
                InputStream inputStream = urlConnection.getInputStream();
                String s=StringNeDao(inputStream);
                Gson gson = new Gson();
                Lei lei = gson.fromJson(s, Lei.class);
                List<Lei.NewslistBean> result = lei.getNewslist();
                Message msg = Message.obtain();
                msg.obj=result;
                mhan.sendMessage(msg);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private String StringNeDao(InputStream stream) {
        StringBuffer b = new StringBuffer();
        String str;
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(stream));
        try {
            while ((str=bufferedReader.readLine())!=null){
                b.append(str);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return b.toString();
    }
}