怎么在Android应用中实现一个查看内存使用情况功能

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package com.itheima28.memorydemo;
 
import Java.io.File;
 
import android.os.Bundle;
import android.os.Environment;
import android.os.StatFs;
import android.support.v7.app.ActionBarActivity;
import android.text.format.Formatter;
import android.widget.TextView;
 
public class MainActivity extends ActionBarActivity {
 
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  
  TextView tvMemoryInfo = (TextView) findViewById(R.id.tv_memory_info);
  
  //获得sd卡的内存状态
  File sdcardFileDir = Environment.getExternalStorageDirectory();
  String sdcardMemory = getMemoryInfo(sdcardFileDir);
 
  //获得手机内部存储控件的状态
  File dataFileDir = Environment.getDataDirectory();
  String dataMemory = getMemoryInfo(dataFileDir);
 
  tvMemoryInfo.setText("SD卡: " + sdcardMemory + "\n手机内部: " + dataMemory);
 }
 
 /**
  * 根据路径获取内存状态
  * @param path
  * @return
  */
 @SuppressWarnings("deprecation")
 private String getMemoryInfo(File path) {
  //获得一个磁盘状态对象
  StatFs stat = new StatFs(path.getPath());
  
  //获得一个扇区的大小
  long blockSize = stat.getBlockSize();
 
  //获得扇区的总数
  long totalBlocks = stat.getBlockCount();
  
  //获得可用的扇区数量
  long availableBlocks = stat.getAvailableBlocks();
 
  //总空间
  String totalMemory = Formatter.formatFileSize(this, totalBlocks * blockSize);
  
  //可用空间
  String availableMemory = Formatter.formatFileSize(this, availableBlocks * blockSize);
  
  return "总空间：" + totalMemory + "\n可用空间：" + availableMemory;
 }
}