Question

我有不同的字符串值，格式为“240.2 KB”，“13.8 MB”，“675字节”等等。

任何人都可以帮我弄清楚如何将这些字符串值转换为数字格式，同时考虑到MB和KB

Answer 1

做这样的事情：

public long ConvertDataSize(string str)
{
    string[] parts = str.Split(' ');

    if (parts.Length != 2)
        throw new Exception("Unexpected input");

    var number_part = parts[0];

    double number = Convert.ToDouble(number_part);

    var unit_part = parts[1];

    var bytes_for_unit = GetNumberOfBytesForUnit(unit_part);

    return Convert.ToInt64(number*bytes_for_unit);

}

private long GetNumberOfBytesForUnit(string unit)
{

    if (unit.Equals("kb", StringComparison.OrdinalIgnoreCase))
        return 1024;

    if (unit.Equals("mb", StringComparison.OrdinalIgnoreCase))
        return 1048576;

    if (unit.Equals("gb", StringComparison.OrdinalIgnoreCase))
        return 1073741824;

    if (unit.Equals("bytes", StringComparison.OrdinalIgnoreCase))
        return 1;

    //Add more rules here to support more units

    throw new Exception("Unexpected unit");
}

现在，您可以像这样使用它：

long result = ConvertDataSize("240.2 KB");

Answer 2

将单位因子存储在字典中：

Dictionary<string, long> units = new Dictionary<string, long>() {
    { "bytes", 1L },
    { "KB", 1L << 10 }, // kilobytes
    { "MB", 1L << 20 }, // megabytes
    { "GB", 1L << 30 }, // gigabytes
    { "TB", 1L << 40 }, // terabytes
    { "PB", 1L << 50 }, // petabytes
    { "EB", 1L << 60 }  // exabytes (who knows how much memory we'll get in future!)
};

我正在使用二进制左移运算符以获得2的幂。不要忘记指定长指示符“L”。否则它将假定为int。

你得到了字节数（为了简单起见我省略了检查）：

private long ToBytes(string s)
{
    string[] parts = s.Split(' ');
    decimal n = Decimal.Parse(parts[0]);
    return (long)(units[parts[1]] * n);
}

将字符串格式的值转换为long

2 个答案: