c# - 格式字符串/数字“NNNNN”

Question

我必须写一个数字的级数，有（每个）5位数字。我的代码是：

int count = 1;
string labelCount = "";
foreach (var directory in folderList)
{
    if (count < 10)
    {
        labelCount = "0000" + count.ToString();
    }
    else if (count < 100)
    {
        labelCount = "000" + count.ToString();
    }
    else if (count < 1000)
    {
        labelCount = "00" + count.ToString();
    }
    else if (count < 10000)
    {
        labelCount = "0" + count.ToString();
    }

    count++;
}

但在我看来，它看起来不太好。有没有办法格式化一个数字（在左边添加 0xN）或者这是唯一的方法？

Answer 1

只需为方法提供格式ToString

var str = count.ToString("00000");

Answer 2

看看String.PadLeft：

string formatted = count.ToString().PadLeft(6, '0');

Answer 3

试试下面的方法，它会帮助你...

labelCount  = string.Format("{0:00000}", count);

有关所有格式，请参见此处：String.Format

Answer 4

就这样去怎么样？

int count = 1;
string labelCount = "";

foreach (var directory in folderList)
{
   int i = 10000;
   while (count < i)
   {
       labelCount += 0;
       i /= 10;
   }

   labelCount += count.ToString();
   count++;
}

Answer 5

您可以通过执行以下操作来实现此目的：

string formatted = count.ToString();
for(int i = 0; i < count - 5; i++)
{
    formatted = "0" + formatted;
}
labelCount.Text = formatted;

编辑：对不起，我的错！应该：

//..
for(int i = 0; i < 5 - count.ToString().Length; i++)
//..