Android 采用线程方法动态显示文字

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今天在学习Android的时候，不知怎么就突然想到了一个动态跳出显示内容的法子，感觉不难，想实现它，搜了搜资料，就完成了一个使句子中的字一个个跳出的Demo如下图所示：

句子太长截取了其中一部分

实现此功能需要实现两个步骤：

1 读文件，把文件中的内容显示在组件上

<span style="font-size:18px;">package com.example.jumpword;import java.io.BufferedReader;import java.io.BufferedWriter;import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.io.UnsupportedEncodingException;import android.util.Log;/** * 按字节读 ， 按字符读， 按行读 * @author jsjxy * */public class readword {                      //处理字节流的超类                  /*inputstream , outputstream;                  //处理字符流的抽象类,(但是会把把字符流转化为字节流)                   inputstreamreader, outputstreamwriter*/                /*  缓冲方式文本读取，缓冲方式文本写入                      *  从输入流中读取文本， 从文本写入输出流                      */                 //BufferedReader ， BufferedWriter                                private static final String TAG = null;File  file  ;     //得到地址                 InputStreamReader    inputstream;          //把内存中的内容解析出来                 FileInputStream    fileinputstream;           //把地址所指向的文件内容读取到内存中                 BufferedReader  reader ;                              //输出，转化为IO能够识别的数据                 int    word;                 String  sentence  = "";              public     readword(){              }           //读txt文件的位置，从txt文件中每次读一个字符             public    String  readword (String path) throws IOException{                   file = new  File(path);                   inputstream = new InputStreamReader(new FileInputStream(file),"GBK");                   reader = new BufferedReader(inputstream);                   while(( word = reader.read() )!=-1){                   //     System.out.println((char) word);                  //每次读一个字符                    Log.i(TAG, (char)word+"");                   sentence += (char)word;                   }                   return   sentence;             }                        //写txt文件                 public  void  writeword(String  path) throws IOException{                          file = new File(path);                          FileOutputStream   outputstream  = new  FileOutputStream(file);                         String  content  = "写入文件的方法";                          outputstream.write(content.getBytes());                 }  }</span>

详细的读写文件的方法如下地址：http://www.cnblogs.com/lovebread/archive/2009/11/23/1609122.html(转别人博客写的) ，在此我不做详细的解释。

2 线程实现间隔时间跳出文字

package com.example.jumpword;import java.io.File;import java.io.IOException;import android.support.v7.app.ActionBarActivity;import android.app.Activity;import android.os.Bundle;import android.os.Environment;import android.util.Log;import android.view.Menu;import android.view.MenuItem;import android.widget.TextView;public class MainActivity extends Activity {                 protected static final String TAG = null;private   TextView     Word;                 // 显示一个字      private    readword   read  = new readword();                  //读取文件的对象          private  File  file;      private  String sentence;                    //返回的读取信息      private  String  jiequchuan ;            //截取的字符串      private  int    i = 1;                                  //截取的位置索引  @Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);     file = Environment.getExternalStorageDirectory();   //地址相当于 “/sdcard.....”try {       sentence = read.readword(file + "/hhh.txt");} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();} Word = (TextView)findViewById(R.id.showword);        new Thread(new Runnable() {  @Overridepublic void run() {// TODO Auto-generated method stub  while(i < sentence.length())    {   try {Thread.sleep(300);} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}                     jiequchuan = sentence.substring(0, i);     //截取字符串方法，从0位置到i位置       runOnUiThread(new Runnable() {@Overridepublic void run() {// TODO Auto-generated method stub     Word.setText(jiequchuan);}});    i++;  }}}).start(); }@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}@Overridepublic boolean onOptionsItemSelected(MenuItem item) {// Handle action bar item clicks here. The action bar will// automatically handle clicks on the Home/Up button, so long// as you specify a parent activity in AndroidManifest.xml.int id = item.getItemId();if (id == R.id.action_settings) {return true;}return super.onOptionsItemSelected(item);}}

以上为实现的主要核心方法，源代码地址如下：http://download.csdn.net/detail/danielntz/9405914

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