Android存储——SD卡或者文件存储实现
Android存储——SD卡或者文件存储实现
Android存储——SD卡或者文件存储实现。Android实现SD卡和实现内存文件存储的做法基本是一样的。只是取得文件路径的方法不一样,基本上跟java的文件操作是一致的,下面是程序的代码。配置取的位置和实现有所不同,其他是一样的,下面是代码:
main.xml:
- <?xml version="1.0" encoding="utf-8"?>
- <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
- android:orientation="vertical"
- android:layout_width="fill_parent"
- android:layout_height="fill_parent">
- <EditText android:id="@+id/edit1"
- android:layout_width="fill_parent"
- android:layout_height="wrap_content"
- android:lines="4"/>
- <Button android:id="@+id/write"
- android:layout_width="wrap_content"
- android:layout_height="wrap_content"
- android:text="@string/write"/>
- <EditText android:id="@+id/edit2"
- android:layout_width="fill_parent"
- android:layout_height="wrap_content"
- android:editable="false"
- android:cursorVisible="false"
- android:lines="4"/>
- <Button android:id="@+id/read"
- android:layout_width="wrap_content"
- android:layout_height="wrap_content"
- android:text="@string/read"/>
- </LinearLayout>
- <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
- <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
- <string name="read">读取</string>
- lt;string name="write">写入</string>
- package cn.jason.io;
- import java.io.FileInputStream;
- import java.io.FileOutputStream;
- import java.io.IOException;
- import java.io.PrintStream;
- import android.app.Activity;
- import android.os.Bundle;
- import android.view.View;
- import android.view.View.OnClickListener;
- import android.widget.Button;
- import android.widget.EditText;
- public class FileTestActivity extends Activity {
- final String FILE = "jason.bin";
- @Override
- public void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.main);
- Button read = (Button) findViewById(R.id.read);
- Button write = (Button) findViewById(R.id.write);
- final EditText edit1 = (EditText) findViewById(R.id.edit1);
- final EditText edit2 = (EditText) findViewById(R.id.edit2);
- write.setOnClickListener(new OnClickListener() {
- @Override
- public void onClick(View v) {
- write(edit1.getText().toString());
- edit1.setText("");
- }
- });
- read.setOnClickListener(new OnClickListener() {
- @Override
- public void onClick(View v) {
- edit2.setText(read());
- }
- });
- }
- private String read() {
- try {
- FileInputStream fis = openFileInput(FILE);
- byte[] buffer = new byte[1024];
- int hasRead = 0;
- StringBuilder sb = new StringBuilder("");
- while ((hasRead = fis.read(buffer)) > 0) {
- sb.append(new String(buffer, 0, hasRead));
- }
- return sb.toString();
- } catch (IOException e) {
- e.printStackTrace();
- }
- return null;
- }
- private void write(String content)
- {
- try
- {
- // 以追加模式打开文件输出流
- FileOutputStream fos = openFileOutput(FILE, MODE_APPEND);
- // 将FileOutputStream包装成PrintStream
- PrintStream ps = new PrintStream(fos);
- // 输出文件内容
- ps.println(content);
- ps.close();
- }
- catch (Exception e)
- {
- e.printStackTrace();
- }
- }
- }
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