Android的文件操作(SD卡)
Android的文件操作(SD卡)
在上次的 中写过直接操作手机自带存储器的程序,这次就接着上次的协议下对sd卡的文件操作。与自带存储不同的是使用sd卡需要用户授权
- <uses-permission Android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
- <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
之后写个方法来保存文件
- public void saveToSD(String filename,String content) throws Exception{
- //getExternalStorageDirectory()可以取得sd卡得路径
- File f=new File(Environment.getExternalStorageDirectory(),filename);
- FileOutputStream out2=new FileOutputStream(f);
- out2.write(content.getBytes());
- out2.close();
- }
- package org.lxh.file;
- import org.lxh.service.FileService;
- import android.app.Activity;
- import android.os.Bundle;
- import android.os.Environment;
- import android.util.Log;
- import android.view.View;
- import android.widget.Button;
- import android.widget.EditText;
- import android.widget.Toast;
- public class FileActivity extends Activity {
- private FileService service;
- public void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.main);
- service=new FileService(this);
- Button button=(Button)findViewById(R.id.button);
- button.setOnClickListener(new View.OnClickListener() {
- public void onClick(View v) {
- EditText filename=(EditText)findViewById(R.id.filename);
- EditText content=(EditText)findViewById(R.id.content);
- try {
- if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
- service.saveToSD(filename.getText().toString(), content.getText().toString());
- Toast.makeText(FileActivity.this, R.string.success, 1).show();
- }else{
- Toast.makeText(FileActivity.this, R.string.sd, 1).show();
- }
- //service.saveFile(filename.getText().toString(), content.getText().toString());
- } catch (Exception e) {
- Toast.makeText(FileActivity.this, R.string.failure, 1).show();
- Log.e("FileActivity", e.getMessage());
- }
- }
- });
- }
- }
- <?xml version="1.0" encoding="utf-8"?>
- <resources>
- <string name="hello">Hello World, FileActivity!</string>
- <string name="app_name">文件的读取</string>
- <string name="filename">输入文件名称</string>
- <string name="content">输入文件内容</string>
- <string name="button">保存</string>
- <string name="success">文件保存成功</string>
- <string name="failure">文件保存失败</string>
- <string name="sd">sd卡不存在或不可用</string>
- </resources>
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