Android SD卡上有多少空闲空间？

import android.os.Environment;
import android.os.StatFs;

public class SDCardUtils {
    public static long getAvailableSpace() {
        String sdCardPath = Environment.getExternalStorageDirectory().getPath();
        StatFs statFs = new StatFs(sdCardPath);
        long blockSize = statFs.getBlockSizeLong();
        long availableBlocks = statFs.getAvailableBlocksLong();
        return availableBlocks * blockSize;
    }
}