黑马Android:获取sd卡剩余容量

import java.io.File;

import android.os.Build;
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 {

protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

File path = Environment.getExternalStorageDirectory();
StatFs stat = new StatFs(path.getPath());
long blockSize;
long totalBlocks;
long availableBlocks;

//获取当前系统版本
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2){
blockSize = stat.getBlockSizeLong();
totalBlocks = stat.getBlockCountLong();
availableBlocks = stat.getAvailableBlocksLong();
}   else{
blockSize = stat.getBlockSize();
totalBlocks = stat.getBlockCount();
availableBlocks = stat.getAvailableBlocks();
}

TextView tv = (TextView) findViewById(R.id.tv);
tv.setText(formatSize(availableBlocks * blockSize));
}

private String formatSize(long size) {
return Formatter.formatFileSize(this, size);
}

}

<!--布局文件-->
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="indi.cc.getsdavail.MainActivity" >

<TextView
android:id="@+id/tv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>

</RelativeLayout>