android 读写文件

MainActivity.java

package cn.itcast.fileio;

import java.io.FileInputStream;
import java.io.FileOutputStream;


import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.EditText;
import android.widget.Toast;


public class MainActivity extends Activity implements OnClickListener {

private EditText etName;
private EditText etAge;
private EditText etContent;


public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

etName = (EditText) findViewById(R.id.etName);
etAge = (EditText) findViewById(R.id.etAge);
etContent = (EditText) findViewById(R.id.etContent);

findViewById(R.id.btnSaveDisk).setOnClickListener(this);
findViewById(R.id.btnReadDisk).setOnClickListener(this);
}

/**
*
*/
public void onClick(View v) {
try {
int id = v.getId();
//添加
if(id == R.id.btnSaveDisk){
String name = etName.getText().toString();
String age = etAge.getText().toString();
FileOutputStream fos = this.openFileOutput("itcast.txt",Activity.MODE_APPEND);
String cont = "name=" + name + ",age=" + age;
fos.write(cont.getBytes());
fos.close();
Toast.makeText(this, "写入完成", 1).show();
//清空文本框
etName.getText().clear();
etAge.getText().clear();
}
//读取
else if(id == R.id.btnReadDisk){
FileInputStream fis = this.openFileInput("itcast.txt");
byte[] bytes = new byte[fis.available()];
fis.read(bytes);
etContent.setText(new String(bytes));
}
} catch (Exception e) {
Log.i("main",e.getMessage());
}
}

}

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"
>
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="name:"
/>
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:id="@+id/etName"
/>
</LinearLayout>
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="age:"
/>
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:id="@+id/etAge"
/>
</LinearLayout>
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="right"
>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="save"
android:id="@+id/btnSaveDisk"
/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="read"
android:id="@+id/btnReadDisk"
/>
</LinearLayout>
<EditText
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:id="@+id/etContent"
/>
</LinearLayout>