复制代码 代码如下:

package com.example.sdcardtest;

import java.io.BufferedReader;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.RandomAccessFile;

import android.os.Bundle;

import android.os.Environment;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.EditText;

import android.app.Activity;

public class MainActivity extends Activity {

final String FILE_NAME = "/lxp.bin";

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

Button write = (Button) findViewById(R.id.main_btn1);

Button read = (Button) findViewById(R.id.main_btn2);

final EditText edit1 = (EditText) findViewById(R.id.main_edit1);

final EditText edit2 = (EditText) findViewById(R.id.main_edit2);

write.setOnClickListener(new OnClickListener() {

@Override

public void onClick(View v) {

write(edit1.getText().toString().trim());

edit1.setText("");

}

});

read.setOnClickListener(new OnClickListener() {

@Override

public void onClick(View v) {

edit2.setText(read());

}

});

}

private void write(String content){

try {

if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){

//获取SD卡的目录

File sdCardDir = Environment.getExternalStorageDirectory();

File targetFile = new File(sdCardDir.getCanonicalPath() + FILE_NAME);

//以指定文件创建RandomAccessFile对象

RandomAccessFile raf = new RandomAccessFile(targetFile, "rw");

//将文件记录指针移动到最后

raf.seek(targetFile.length());

//输出文件内容

raf.write(content.getBytes());

raf.close();

}

} catch (Exception e) {

e.printStackTrace();

}

}

private String read(){

try {

if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){

//获得SD卡对应的存储目录

File sdCardDir = Environment.getExternalStorageDirectory();

//获取指定文件对应的输入流

FileInputStream fis = new FileInputStream(sdCardDir.getCanonicalPath() + FILE_NAME);

//将指定输入流包装成BufferReader

BufferedReader br = new BufferedReader(new InputStreamReader(fis));

StringBuilder sb = new StringBuilder("");

String line = null;

//循环读取文件内容

while((line = br.readLine()) != null){

sb.append(line);

}

br.close();

return sb.toString();

}

} catch (Exception e) {

e.printStackTrace();

}

return null;

}

}

最后别忘了在AndroidManafest.xml中增加访问读取SD的权限。

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