Question

DriveInfo[] drives = DriveInfo.GetDrives();
for (int i = 0; i < drives.Length; i++)
{
    if (drives[i].IsReady)
    {
        Console.WriteLine("Drive {0} - Has free space of {1} GB",drives[i].ToString(),(drives[i].TotalFreeSpace/1024/1024/1024).ToString("N2"));
    }
}

输出：

Drive C:\ - Has free space of 70,00 GB
Drive D:\ - Has free space of 31,00 GB
Drive E:\ - Has free space of 7,00 GB
Drive F:\ - Has free space of 137,00 GB

所有结果都是00，但我需要显示实际尺寸。那么哪种格式合适？

Answer 1

格式字符串与它没有任何关系。您的整数运算正在丢弃任何余数。

3920139012 / 1024 / 1024  / 1024 // 3

使用m后缀指定小数，如下所示：

3920139012 / 1024m / 1024m / 1024m // 3.6509139575064182281494140625

可替换地：

3920139012 / Math.Pow(1024, 3) // 3.65091395750642

这可能会更清楚一点：

var gb = Math.Pow(1024, 3);
foreach(var drive in DriveInfo.GetDrives())
{   
    if(drive.IsReady)
    {
        Console.WriteLine("Drive {0} - Has free space of {1:n2} GB",
            drive.Name,
            drive.TotalFreeSpace / gb);
    }
}

Answer 2

因为您正在执行整数除法，它会截断小数余数。改为使用浮点除法：

drives[i].TotalFreeSpace/1024.0/1024.0/1024.0

或

drives[i].TotalFreeSpace / (1024.0 * 1024.0 * 1024.0)

带有十进制格式的C＃string.format。

2 个答案: