数据存储，actionbar导航，sd卡的file类，StatFs类，Formatter类使用

package com.example.demo1;

import java.io.File;

import android.annotation.SuppressLint;

import android.app.ActionBar;

import android.app.ActionBar.TabListener;

import android.app.Activity;

import android.app.FragmentTransaction;

import android.app.ActionBar.Tab;

import android.content.SharedPreferences;

import android.os.Bundle;

import android.os.Environment;

import android.os.StatFs;

import android.text.format.Formatter;

import android.util.Log;

import android.widget.Toast;

public class MainActivity extends Activity {

private final String Myfoler="MyFolder";

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

ActionBar actionBar=getActionBar();

actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

Tab tab=actionBar.newTab();

tab.setText("第一个");

actionBar.setLogo(R.drawable.small);

tab.setIcon(R.drawable.small);

tab.setTabListener(new TabListener() {

@Override

public void onTabUnselected(Tab tab, FragmentTransaction ft) {

// TODO 自动生成的方法存根

}

@Override

public void onTabSelected(Tab tab, FragmentTransaction ft) {

Toast.makeText(MainActivity.this, "第一个",2000 ).show();

SharedPreferences sharedPreferences=getSharedPreferences(Myfoler,0);

sharedPreferences.edit().putInt("age", 17).putString("name"," 张靖尉").commit();

}

@Override

public void onTabReselected(Tab tab, FragmentTransaction ft) {

// TODO 自动生成的方法存根

}

});

Tab tab2=actionBar.newTab();

tab2.setText("第二个");

tab2.setIcon(R.drawable.small);

tab2.setTabListener(new TabListener() {

@Override

public void onTabUnselected(Tab tab, FragmentTransaction ft) {

// TODO 自动生成的方法存根

}

@Override

public void onTabSelected(Tab tab, FragmentTransaction ft) {

Toast.makeText(MainActivity.this, "第二个",2000 ).show();

SharedPreferences sharedPreferences=getSharedPreferences(Myfoler, 0);

int myage=sharedPreferences.getInt("age",0);

String myname=sharedPreferences.getString("name", " ");

Toast.makeText(MainActivity.this,"我的名字:"+myname+"年龄："+myage,3000).show();

}

@Override

public void onTabReselected(Tab tab, FragmentTransaction ft) {

// TODO 自动生成的方法存根

}

});

Tab tab3=actionBar.newTab();

tab3.setText("第三个");

tab3.setIcon(R.drawable.small);

tab3.setTabListener(new TabListener() {

@Override

public void onTabUnselected(Tab tab, FragmentTransaction ft) {

// TODO 自动生成的方法存根

}

@SuppressLint("NewApi")

@SuppressWarnings("static-access")

@Override

public void onTabSelected(Tab tab, FragmentTransaction ft) {

File path=Environment.getExternalStorageDirectory();

StatFs sFs=new StatFs(path.getPath());

long remaining =sFs.getAvailableBytes();//获取sd卡当前可用字节

long count=sFs.getBlockCountLong();

long size=sFs.getBlockSizeLong();

long capacity=count*size;

//Environment environment=new Environment();

//String ss=path.getAbsolutePath();

String myremaining=Formatter.formatFileSize(MainActivity.this, remaining);

String mycapacity=Formatter.formatFileSize(MainActivity.this, capacity);

Toast.makeText(MainActivity.this,mycapacity,2000).show();

}

@Override

public void onTabReselected(Tab tab, FragmentTransaction ft) {

// TODO 自动生成的方法存根

}

});

actionBar.addTab(tab);

actionBar.addTab(tab2);

actionBar.addTab(tab3);

}

private void ExternalStorageState(){

if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){

Toast.makeText(MainActivity.this,"存在sd卡", 2000).show();

}

else {

Toast.makeText(MainActivity.this,"不存在sd卡", 2000).show();

}

}

}