<?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="vertical" >

     <ScrollView

         android:id="@+id/scrollView1"

         android:layout_width="match_parent"

         android:layout_height="wrap_content" >

         <LinearLayout

             android:layout_width="match_parent"

             android:layout_height="wrap_content"

             android:orientation="vertical" >

             <TextView

                 android:id="@+id/tv"

                 android:layout_width="match_parent"

                 android:layout_height="wrap_content"

                 android:text="TextView" />

         </LinearLayout>

     </ScrollView>

  </LinearLayout>

 package com.example.mulitthreadactivitydemo;

 import java.io.RandomAccessFile;

 import java.util.ArrayList;

 import java.util.List;

 import android.util.Log;

 public class FileRead {

     boolean readend = false;

     List<String> al = null;

     private static final String Tag = "addfile";

     public class ReadNodesThread extends Thread {// 读取线程

         public void run() {

             al = new ArrayList<String>(100);

             al.clear();

             readend = false;

             int i = 0;

             try {

                 String dirstr = "/storage/sdcard0/DCIM/test.txt";

                 //RandomAccessFile raf = new RandomAccessFile("/sdcard/test.txt","r");

                 RandomAccessFile raf = new RandomAccessFile(dirstr,"r");

                 // try {

                 while (raf.getFilePointer() < raf.length()) {

                     al.add(raf.readLine());

                     Log.i(Tag,"addfile = " + raf.readLine());

                     // sleep(100);//如果测试文件太小，这里休眠是为了测试，

                 }

             } catch (Exception e1) {

                 // TODO Auto-generated catch block

                 e1.printStackTrace();

             }

             readend = true;

         }

     };

 }

 package com.example.mulitthreadactivitydemo;

 import android.app.Activity;

 import android.os.Bundle;

 import android.os.Handler;

 import android.widget.TextView;

 public class MainActivity extends Activity {

     FileRead fr=null;

     Handler mHandler=null;

     int curi=0;

     Runnable updateui=null;

     String[] tmp=null;

     String s="";

     TextView tv=null;

     class ReadListener extends Thread{//监听线程，当数据更新数目大于10条时，更新UI

         public void run()

         {

             int i=0,newi=0;

             while(!fr.readend)

             {

                 newi=fr.al.size();

                 if((newi-i)>10)//新增数据大于10条，更新UI

                 {

                     i=newi;

                     tmp=(String[])fr.al.toArray(new String[fr.al.size()]);

                     mHandler.post(updateui);

                     try {

                         Thread.sleep(100);

                     } catch (InterruptedException e) {

                         // TODO Auto-generated catch block

                         e.printStackTrace();

                     }

                 }

             }

             //数据读完了

             tmp=(String[])fr.al.toArray(new String[fr.al.size()]);

             mHandler.post(updateui);

             try {

                 Thread.sleep(100);

             } catch (InterruptedException e) {

                 // TODO Auto-generated catch block

                 e.printStackTrace();

             }

         }

     };

     @Override

     protected void onCreate(Bundle savedInstanceState) {

         super.onCreate(savedInstanceState);

         setContentView(R.layout.activity_main);

         tv = (TextView) findViewById(R.id.tv);

         fr=new FileRead();

         FileRead.ReadNodesThread readThread = fr.new ReadNodesThread();

         updateui = new Runnable()//更新UI的线程

         {

             @Override

             public void run() {

                 // TODO Auto-generated method stub

                 int i=0;

                 for(i=curi;i<tmp.length;i++)

                 {

                     s+=tmp[i]+"\n";

                 }

                 tv.setText(s);

                 curi=i;

             }};

         readThread.start();

         ReadListener updateThread=new ReadListener();

         mHandler=new Handler();

         updateThread.start();

     }

 }