Android利用StatFs查看SDCard物理信息

package cn.sohu.com;
//1 查看SDCard相关信息的主要使用到的是StatFs类,没有其余难点
//2 从SDCard中读取txt文件要注意
//  第一:txt文件应该要按照UTF-8保存的.因为默认的是ANSI编码的！！！！！
//  第二:不能使用openFileInput(filePath)方法获取输入流.因为此方法的参数要求不能含有路径分隔符.
//       若这么做,报错：………………………………………………cannot contain  path separator
//
//
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.os.StatFs;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class TestSDCardActivity extends Activity {
   private Button SDbutton;
   private Button Filebutton;
   private TextView textView;
   private EditText editText;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);       
        SDbutton=(Button) findViewById(R.id.Button1);
        Filebutton=(Button) findViewById(R.id.Button2);
        textView=(TextView) findViewById(R.id.textView);       
        SDbutton.setOnClickListener(new OnClickListener() {			
			@Override
			public void onClick(View v) {		
				if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){//判断是否安装SDCard
					File SDFile=Environment.getExternalStorageDirectory();
					StatFs statFs=new StatFs(SDFile.getPath());
					long blockSize=statFs.getBlockSize();//块容量
					float blocksCount=statFs.getBlockCount();//块数量					
					int sizeM=(int) ((blockSize*blocksCount)/1024/1024);//总容量
					long ableBlocks=statFs.getAvailableBlocks();//可用容量
					int percent=(int) ((ableBlocks/blocksCount)*100);//可用百分比
					textView.setText("SDCard使用情况如下:\n"+"blockSize="+blockSize+",totalBlocks="+blocksCount+",sizeM="+sizeM+",ableBlocks="+ableBlocks+"\n"+"使用率:\n"+percent+"%");																	
				}else{
					Toast.makeText(getApplicationContext(), "未找到SDCard", 1).show();
				}				
			}
		});
        Filebutton.setOnClickListener(new OnClickListener() {			
			@Override
			public void onClick(View v) {
			       editText =(EditText) findViewById(R.id.editeView);
			       String fileName=editText.getText().toString();
			       String filePath=Environment.getExternalStorageDirectory().toString()+"/"+fileName;			       			       
				   try {
					String result=read(filePath);
					Log.i("Tag", "result="+result);
					textView.setText(result);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		});
    }
    

	public String read(String filePath) throws Exception{
		//openFileInput方法的参数cannot contain  path separator
		File file=new File(filePath);
		FileInputStream inputStream=new FileInputStream(file);
		//FileInputStream inputStream=TestSDCardActivity.this.openFileInput(filePath);//注意这句代码！！！！！
		ByteArrayOutputStream outputStream=new ByteArrayOutputStream();
		byte [] b=new byte[1024];
		int len=0;
		while((len=inputStream.read(b))!=-1){
			outputStream.write(b, 0, len);
			Log.i("Tag", "len="+len);
		}
		outputStream.flush();
		String result=outputStream.toString("UTF-8");
		outputStream.close();
		inputStream.close();
		return result;
	}
}