Android在外部存储器中读取数据

来源:互联网 发布:张正隆雪白血红知乎 编辑:程序博客网 时间:2024/06/05 20:11
package com.itheima.rwinrom;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.InputStreamReader;

import org.apache.http.entity.InputStreamEntity;

import com.itheima.rwinsd.R;

import android.os.Bundle;
import android.os.Environment;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity {

private EditText et_name;
private EditText et_pass;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

et_name = (EditText) findViewById(R.id.et_name);
et_pass = (EditText) findViewById(R.id.et_pass);

readAccount();

}

public void readAccount(){
if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
File file = new File("sdcard/info.txt");
if(file.exists()){
try {
FileInputStream fis = new FileInputStream(file);
//把字节流转换成字符流
BufferedReader br = new BufferedReader(new InputStreamReader(fis));
//读取txt文件里的用户名和密码
String text = br.readLine();
String[] s = text.split("##");

et_name.setText(s[0]);
et_pass.setText(s[1]);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}

public void login(View v){

String name = et_name.getText().toString();
String pass = et_pass.getText().toString();

CheckBox cb = (CheckBox) findViewById(R.id.cb);
//判断选框是否被勾选
if(cb.isChecked()){
//MEDIA_UNKNOWN:不能识别sd卡
//MEDIA_REMOVED:没有sd卡
//MEDIA_UNMOUNTED:sd卡存在但是没有挂载
//MEDIA_CHECKING:sd卡正在准备
//MEDIA_MOUNTED:sd卡已经挂载,可用
if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){

//返回一个File对象,其路径是sd卡的真实路径
File file = new File(Environment.getExternalStorageDirectory(), "info.txt");
// File file = new File("sdcard/info.txt");
FileOutputStream fos;
try {
fos = new FileOutputStream(file);
fos.write((name + "##" + pass).getBytes());
fos.close();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
else{
Toast.makeText(this, "sd卡不可用哟亲么么哒", 0).show();
}
}

//创建并显示吐司对话框
Toast.makeText(this, "登录成功", 0).show();
}

}
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