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如果运行时，可以看到滚动条由条慢慢变短，则说明程序成功了。截图如下，建议选择大点的文件做测试。

   

main.xml

<?xml version="1.0" encoding="utf-8"?>

<ScrollView  xmlns:android="http://schemas.android.com/apk/res/android" android:layout_height="wrap_content" android:id="@+id/scrollView1" android:layout_width="fill_parent">     <LinearLayout android:id="@+id/linearLayout1"      android:orientation="vertical"         android:layout_width="fill_parent"      android:layout_height="wrap_content">  <TextView   android:id="@+id/tv"     android:layout_width="fill_parent"      android:layout_height="wrap_content"         />     </LinearLayout> </ScrollView>

FileRead.java

public class FileRead {

boolean readend=false; List<String> al=null; 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 { RandomAccessFile raf=new RandomAccessFile("/sdcard/test.txt","r"); //try { while(raf.getFilePointer()<raf.length()) { al.add(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; } }; }

MultiThreadActivity.java

public class MultiThreadActivity 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 public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); tv=(TextView)findViewById(R.id.tv); fr=new 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(); } }