how?

java

我只能做出这样的

import android.os.StatFs;
import android.os.Environment;
import java.io.File;
import android.text.format.Formatter;
public void readStystem(){
File root = Environment.getDataDirectory();
StatFs info = new StatFs(root.getPath());
long size = info.getBlockSize();
long count = info.getBlockCount();
long num = info.getAvailableBlocks();
//全部空间
String a = Formatter.formatFileSize(activity,size*count);
syso(a);
//剩余空间
String b = Formatter.formatFileSize(activity,size*num);
syso(b);
}

多谢