1、工程目录
2、MainActivity.java
package com.example.test_file;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
public class MainActivity extends Activity {
private EditText myEdit01, myEdit02;
private Button myBtn01, myBtn02;
// 文件名称字符串常量
private static final String FILE_NAME = "temp.txt";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
myBtn01 = (Button) findViewById(R.id.button01);
myBtn02 = (Button) findViewById(R.id.button02);
myEdit01 = (EditText) findViewById(R.id.edit01);
myEdit02 = (EditText) findViewById(R.id.edit02);
myBtn01.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
// 写内容
write(myEdit01.getText().toString());
}
});
myBtn02.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
// 读内容
myEdit02.setText(read());
}
});
}
// 读文件方法
private String read() {
try {
// 实例化文件输入流
FileInputStream fis = openFileInput(FILE_NAME);
// 定义缓存数组
byte[] buffer = new byte[fis.available()];
// 读到缓冲区
fis.read(buffer);
System.out.println("读取文件成功");
return new String(buffer);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
// 写文件方法
private void write(String content) {
try {
// 实例化文件输出流
FileOutputStream fos = openFileOutput(FILE_NAME, MODE_APPEND);
// 写内容
fos.write(content.getBytes());
System.out.println("写入文件成功");
// 关闭文件流
fos.close();
} catch (Exception e) {
e.printStackTrace();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
3、main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<EditText
android:id="@+id/edit01"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:lines="4"
android:text="" />
<Button
android:id="@+id/button01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="写入文件" />
<EditText
android:id="@+id/edit02"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:lines="4"
android:text="" />
<Button
android:id="@+id/button02"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="读取文件" />
</LinearLayout>