Android 小项目之--解析如何获取SDCard 内存

package  com.terry;

import  java.io.File;
import  java.text.DecimalFormat;

import  android.R.integer;
import  android.app.Activity;
import  android.os.Bundle;
import  android.os.Environment;
import  android.os.StatFs;
import  android.view.View;
import  android.view.View.OnClickListener;
import  android.widget.Button;
import  android.widget.ProgressBar;
import  android.widget.TextView;
import  android.widget.Toast;

public   class  getStorageActivity  extends  Activity {
     private  Button myButton;
     /**  Called when the activity is first created.  */
    @Override
     public   void  onCreate(Bundle savedInstanceState) {
         super .onCreate(savedInstanceState);
        setContentView(R.layout.main); 
        findView();
        viewHolder.myButton.setOnClickListener( new  OnClickListener() {
            
            @Override
             public   void  onClick(View arg0) {
                 //  TODO Auto-generated method stub
                getSize();
            }
        });
    }
    
    
     void  findView(){
        viewHolder.myButton = (Button)findViewById(R.id.Button01);
        viewHolder.myBar = (ProgressBar)findViewById(R.id.myProgressBar);
        viewHolder.myTextView = (TextView)findViewById(R.id.myTextView);
    }
    
    
    
     void  getSize(){
        viewHolder.myTextView.setText( "" );
        viewHolder.myBar.setProgress( 0 );
         // 判断是否有插入存储卡
         if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
            File path  = Environment.getExternalStorageDirectory();
             // 取得sdcard文件路径
            StatFs statfs = new  StatFs(path.getPath());
             // 获取block的SIZE
             long  blocSize = statfs.getBlockSize();
             // 获取BLOCK数量
             long  totalBlocks = statfs.getBlockCount();
             // 己使用的Block的数量
             long  availaBlock = statfs.getAvailableBlocks();
            
            String[] total = filesize(totalBlocks * blocSize);
            String[] availale = filesize(availaBlock * blocSize);
             // 设置进度条的最大值 
             int  maxValue = Integer.parseInt(availale[ 0 ])
             * viewHolder.myBar.getMax() / Integer.parseInt(total[ 0 ]);
            viewHolder.myBar.setProgress(maxValue);
            String Text = " 总共： " + total[ 0 ] + total[ 1 ] + " \n "
             + " 可用: " + availale[ 0 ] + availale[ 1 ]; 
            viewHolder.myTextView.setText(Text);
            
        } else   if (Environment.getExternalStorageState().equals(Environment.MEDIA_REMOVED)){
            Toast.makeText(getStorageActivity. this ,  " 没有sdCard " ,  1000 ).show();
        }
    }
    
     // 返回数组，下标1代表大小，下标2代表单位 KB/MB
    String[] filesize( long  size){
        String str = "" ;
         if (size >= 1024 ){
            str = " KB " ;
            size /= 1024 ;
             if (size >= 1024 ){
                str = " MB " ;
                size /= 1024 ;
            }
        }
        DecimalFormat formatter = new  DecimalFormat();
        formatter.setGroupingSize( 3 );
        String result[]  = new  String[ 2 ];
        result[ 0 ] = formatter.format(size);
        result[ 1 ] = str;
         return  result;
    }
}