android阅读器阅读txt文件
浏览数：25 /
时间：2015年06月11日
很早前就想做一个小说阅读器的。最近终于做了下来。
其实很简单，这里只做了一小部分显示部分，还有标签，回翻的部分没有做。
读取文件采用RandomAccessFile对大文件进行操作。
早前使用read(byte[]
b)
进行读取，可是总是有些意外，就是偶尔在一页的最后一行的几个字符出现乱码，导致下一页的前部分也会有乱码。而且这个问题很奇怪，自己在纯java环境中是没有任何的问题，可是只要在android虚拟机中就出现问题了。
后来采用readLine()方法。
一下是全部代码：
package com.duduli.li; import java.io.File; import java.io.FileNotFoundException; import java.io.IOException; import java.io.RandomAccessFile; import android.app.Activity; import android.os.Bundle; import android.view.MotionEvent; import android.view.View; import android.view.View.OnTouchListener; import android.widget.ScrollView; import android.widget.TextView; public class Ibook2Activity extends Activity { private ScrollView sv; private TextView tv; private RandomAccessFile raf; private int scrollViewY = 0; private StringBuilder sb; private long currentPoint; private long fileLeght; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); // sv = (ScrollView) this.findViewById(R.id.scrollView); tv = (TextView) this.findViewById(R.id.textView); sv = (ScrollView) this.findViewById(R.id.scrollView); File file = new File("/sdcard/zhuxian.txt"); try { raf = new RandomAccessFile(file, "r"); fileLeght = raf.length(); System.out.println("文件总长度: "+fileLeght); sb = new StringBuilder(); for(int i=0; i<=50;i++){ if(raf.getFilePointer() != fileLeght){ // string += new String(raf.readLine().getBytes("8859_1"), "gb2312")+("\r\n"); sb.append(new String(raf.readLine().getBytes("8859_1"), "gb2312")+("\r\n")); // break; }else{ break; } } // System.out.println(sb); currentPoint = raf.getFilePointer(); System.out.println(currentPoint); tv.setText(sb); // tv.setText(string); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } sv.setOnTouchListener(new OnTouchListener() { @Override public boolean onTouch(View v, MotionEvent event) { // TODO Auto-generated method stub // string = ""; if(event.getAction() == MotionEvent.ACTION_UP){ if (sv.getScrollY() == 0) { System.out.println("up"); } else if (sv.getScrollY() - scrollViewY < 2 && sv.getScrollY() >= scrollViewY) { try { raf.seek(currentPoint); sb.delete(0, sb.length()); for(int i=0; i<=50;i++){ if(raf.getFilePointer() != fileLeght){ // string += new String(raf.readLine().getBytes("8859_1"), "gb2312")+("\r\n"); sb.append(new String(raf.readLine().getBytes("8859_1"), "gb2312")+("\r\n")); // break; }else{ break; } } // System.out.println(string); currentPoint = raf.getFilePointer(); tv.setText(sb); // tv.setText(string); sv.scrollTo(0, 0); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } else { scrollViewY = sv.getScrollY(); // System.out.println(sv.getScrollY()); } System.out.println("currentPoint: "+currentPoint); System.out.println("ScrollY: "+sv.getScrollY()); } return false; } }); } }
续：下面这个代码加入获得到达底部进行toast提示。
package com.duduli.li; import java.io.File; import java.io.FileNotFoundException; import java.io.IOException; import java.io.RandomAccessFile; import android.app.Activity; import android.os.Bundle; import android.view.MotionEvent; import android.view.View; import android.view.View.OnTouchListener; import android.widget.ScrollView; import android.widget.TextView; import android.widget.Toast; public class Ibook2Activity extends Activity { private ScrollView sv; private TextView tv; private RandomAccessFile raf; private int scrollViewY = 0; private StringBuilder sb; private long currentPoint; private long fileLeght; private boolean flag = true; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); // sv = (ScrollView) this.findViewById(R.id.scrollView); tv = (TextView) this.findViewById(R.id.textView); sv = (ScrollView) this.findViewById(R.id.scrollView); File file = new File("/sdcard/test.txt"); try { raf = new RandomAccessFile(file, "r"); fileLeght = raf.length(); System.out.println("文件总长度: "+fileLeght); sb = new StringBuilder(); for(int i=0; i<=50;i++){ if(raf.getFilePointer() != fileLeght){ // string += new String(raf.readLine().getBytes("8859_1"), "gb2312")+("\r\n"); sb.append(new String(raf.readLine().getBytes("8859_1"), "gb2312")+("\r\n")); // break; }else{ break; } } // System.out.println(sb); currentPoint = raf.getFilePointer(); System.out.println(currentPoint); tv.setText(sb); // tv.setText(string); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } sv.setOnTouchListener(new OnTouchListener() { @Override public boolean onTouch(View v, MotionEvent event) { // TODO Auto-generated method stub // string = ""; if(event.getAction() == MotionEvent.ACTION_UP){ if (sv.getScrollY() == 0) { System.out.println("up"); } else if (sv.getScrollY() - scrollViewY < 2 && sv.getScrollY() >= scrollViewY) { try { if(flag){ System.out.println("begin"); raf.seek(currentPoint); sb.delete(0, sb.length()); for(int i=0; i<=50;i++){ if(raf.getFilePointer() != fileLeght){ // string += new String(raf.readLine().getBytes("8859_1"), "gb2312")+("\r\n"); sb.append(new String(raf.readLine().getBytes("8859_1"), "gb2312")+("\r\n")); // break; }else{ // flag = false; break; } } // System.out.println(string); currentPoint = raf.getFilePointer(); tv.setText(sb); // tv.setText(string); sv.scrollTo(0, 0); } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } else { scrollViewY = sv.getScrollY(); // System.out.println(sv.getScrollY()); } if(!flag && (tv.getHeight() - sv.getScrollY() <= 362)){ Toast.makeText(getApplicationContext(), "本文已结束", Toast.LENGTH_SHORT).show(); } System.out.println(tv.getHeight()); System.out.println(sv.getScrollY()); } return false; } }); } }
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