如何在C＃中将'int'转换为'char'？

Question

I have a string variable which has a mixture of numbers and letters. I want to create a new string that only has int values of the previous string variable. So I found two ways to cast int to char . However, they do not work. Here's what I've tried

string onlyNumberString = "";
foreach (char onlyNum in puzzleData)
{
    for (int i = 1; i < 10; i++)
    {
        if (onlyNum == (char)i)
        {
            onlyNumberString += onlyNum;
        }
    }
}

and

string onlyNumberString = "";
foreach (char onlyNum in puzzleData)
{
    for (int i = 1; i < 10; i++)
    {
        if (onlyNum == Convert.ToChar(i))
        {
            onlyNumberString += onlyNum;
        }
    }
}

Answer 1

Use Char.IsDigit instead, far simpler.

StringBuilder onlyNumber = new StringBuilder();
foreach (char onlyNum in puzzleData)
{
    if (Char.IsDigit(onlyNum))
    {
        onlyNumber.Append(onlyNum);
    }
}

Answer 2

You can just cast an int to a char it directly:

var myChar = (char)20;

But to do what you want I suggest using a regular expression:

var onlyNumerals = Regex.Replace(myString, @"[^0-9]", "");

The above will replace any character that is not 0-9 with an empty space.

An alternative, using LINQ and char.IsDigit :

 var onlyNumeral = new string(myString.Where(c => Char.IsDigit(c)).ToArray());

Answer 3

int iNum = 2;

char cChar = iNum.ToString()[0];

Will work for x when 0 <= x <= 9.

Answer 4

您可以按照以下方式进行操作：

string justNumbers = new String(text.Where(Char.IsDigit).ToArray());

Answer 5

A few ways:

(char)int

Or

int.Parse(char.ToString())

Or

Convert.ToChar(int);