VB的Asc()和Chr()函数在c#中是什么?

VB has a couple of native functions for converting a char to an ASCII value and vice versa - Asc() and Chr().

VB有一些本地函数，可以将一个字符转换为ASCII值，反之亦然——Asc()和Chr()。

Now I need to get the equivalent functionality in C#. What's the best way?

现在我需要在c#中获得等价的功能。最好的方法是什么?

7 个解决方案

#1

You could always add a reference to Microsoft.VisualBasic and then use the exact same methods: Strings.Chr and Strings.Asc.

你可以给微软添加一个参考。VisualBasic然后使用完全相同的方法:字符串。空空和Strings.Asc。

That's the easiest way to get the exact same functionality.

这是得到完全相同功能的最简单方法。

#2

For Asc() you can cast the char to an int like this:

对于Asc()，可以将char类型转换成这样的int类型:

int i = (int)your_char;

and for Chr() you can cast back to a char from an int like this:

对于Chr()，您可以从这样的int类型转换为char:

char c = (char)your_int;

Here is a small program that demonstrates the entire thing:

这里有一个小程序演示了整个事情:

using System;

class Program
{
    static void Main()
    {
        char c = 'A';
        int i = 65;

        // both print "True"
        Console.WriteLine(i == (int)c);
        Console.WriteLine(c == (char)i);
    }
}

#3

For Chr() you can use:

对于Chr()你可以使用:

char chr = (char)you_char_value;

#4

I got these using resharper, the exact code runs by VB on your machine

我使用resharper，用VB在你的机器上运行的代码。

/// <summary>
/// Returns the character associated with the specified character code.
/// </summary>
/// 
/// <returns>
/// Returns the character associated with the specified character code.
/// </returns>
/// <param name="CharCode">Required. An Integer expression representing the <paramref name="code point"/>, or character code, for the character.</param><exception cref="T:System.ArgumentException"><paramref name="CharCode"/> &lt; 0 or &gt; 255 for Chr.</exception><filterpriority>1</filterpriority>
public static char Chr(int CharCode)
{
  if (CharCode < (int) short.MinValue || CharCode > (int) ushort.MaxValue)
    throw new ArgumentException(Utils.GetResourceString("Argument_RangeTwoBytes1", new string[1]
    {
      "CharCode"
    }));
  if (CharCode >= 0 && CharCode <= (int) sbyte.MaxValue)
    return Convert.ToChar(CharCode);
  try
  {
    Encoding encoding = Encoding.GetEncoding(Utils.GetLocaleCodePage());
    if (encoding.IsSingleByte && (CharCode < 0 || CharCode > (int) byte.MaxValue))
      throw ExceptionUtils.VbMakeException(5);
    char[] chars = new char[2];
    byte[] bytes = new byte[2];
    Decoder decoder = encoding.GetDecoder();
    if (CharCode >= 0 && CharCode <= (int) byte.MaxValue)
    {
      bytes[0] = checked ((byte) (CharCode & (int) byte.MaxValue));
      decoder.GetChars(bytes, 0, 1, chars, 0);
    }
    else
    {
      bytes[0] = checked ((byte) ((CharCode & 65280) >> 8));
      bytes[1] = checked ((byte) (CharCode & (int) byte.MaxValue));
      decoder.GetChars(bytes, 0, 2, chars, 0);
    }
    return chars[0];
  }
  catch (Exception ex)
  {
    throw ex;
  }
}


/// <summary>
/// Returns an Integer value representing the character code corresponding to a character.
/// </summary>
/// 
/// <returns>
/// Returns an Integer value representing the character code corresponding to a character.
/// </returns>
/// <param name="String">Required. Any valid Char or String expression. If <paramref name="String"/> is a String expression, only the first character of the string is used for input. If <paramref name="String"/> is Nothing or contains no characters, an <see cref="T:System.ArgumentException"/> error occurs.</param><filterpriority>1</filterpriority>
public static int Asc(char String)
{
  int num1 = Convert.ToInt32(String);
  if (num1 < 128)
    return num1;
  try
  {
    Encoding fileIoEncoding = Utils.GetFileIOEncoding();
    char[] chars = new char[1]
    {
      String
    };
    if (fileIoEncoding.IsSingleByte)
    {
      byte[] bytes = new byte[1];
      fileIoEncoding.GetBytes(chars, 0, 1, bytes, 0);
      return (int) bytes[0];
    }
    byte[] bytes1 = new byte[2];
    if (fileIoEncoding.GetBytes(chars, 0, 1, bytes1, 0) == 1)
      return (int) bytes1[0];
    if (BitConverter.IsLittleEndian)
    {
      byte num2 = bytes1[0];
      bytes1[0] = bytes1[1];
      bytes1[1] = num2;
    }
    return (int) BitConverter.ToInt16(bytes1, 0);
  }
  catch (Exception ex)
  {
    throw ex;
  }
}


/// <summary>
/// Returns an Integer value representing the character code corresponding to a character.
/// </summary>
/// 
/// <returns>
/// Returns an Integer value representing the character code corresponding to a character.
/// </returns>
/// <param name="String">Required. Any valid Char or String expression. If <paramref name="String"/> is a String expression, only the first character of the string is used for input. If <paramref name="String"/> is Nothing or contains no characters, an <see cref="T:System.ArgumentException"/> error occurs.</param><filterpriority>1</filterpriority>
public static int Asc(string String)
{
  if (String == null || String.Length == 0)
    throw new ArgumentException(Utils.GetResourceString("Argument_LengthGTZero1", new string[1]
    {
      "String"
    }));
  return Strings.Asc(String[0]);
}

Resources are just stored error message, so somehow the way you want ignore them, and the other two method which you do not have access to are as follow:

资源只是存储错误消息，所以您想要忽略它们的方式，以及您无法访问的其他两种方法如下:

internal static Encoding GetFileIOEncoding()
{
    return Encoding.Default;
}

internal static int GetLocaleCodePage()
{
    return Thread.CurrentThread.CurrentCulture.TextInfo.ANSICodePage;
}

#5

Strings.Asc is not equivalent with a plain C# cast for non ASCII chars that can go beyond 127 code value. The answer I found on https://social.msdn.microsoft.com/Forums/vstudio/en-US/13fec271-9a97-4b71-ab28-4911ff3ecca0/equivalent-in-c-of-asc-chr-functions-of-vb?forum=csharpgeneral amounts to something like this:

字符串。Asc与非ASCII字符的普通c#转换不一样，它可以超过127个代码值。我在https://social.msdn.microsoft.com/forums/vstudio/vstudio/13fec271 -9a97-4b71-ab28- 4911ff3ecca0/- in-c-of- c-of- c-of- of- c-of- of- c-of- of- c-of- of- c-of- c-of- c-of- of- c-of- c-of- of- c-of- of- c-of- c-of- c-of- c-of- c-of- c-of- c-论坛=csharpgeneral相当于这样:

    static int Asc(char c)
    {
        int converted = c;
        if (converted >= 0x80)
        {
            byte[] buffer = new byte[2];
            // if the resulting conversion is 1 byte in length, just use the value
            if (System.Text.Encoding.Default.GetBytes(new char[] { c }, 0, 1, buffer, 0) == 1)
            {
                converted = buffer[0];
            }
            else
            {
                // byte swap bytes 1 and 2;
                converted = buffer[0] << 16 | buffer[1];
            }
        }
        return converted;
    }

Or, if you want the read deal add a reference to Microsoft.VisualBasic assembly.

或者，如果你想让阅读协议添加一个关于微软的参考。VisualBasic组装。

#6

 //Char to Int - ASC("]")
 int lIntAsc = (int)Char.Parse("]");
 Console.WriteLine(lIntAsc); //Return 91



 //Int to Char

char lChrChar = (char)91;
Console.WriteLine(lChrChar ); //Return "]"

#7

Given char c and int i, and functions fi(int) and fc(char):

给定char c和int i，以及函数fi(int)和fc(char):

From char to int (analog of VB Asc()): explicitly cast the char as an int: int i = (int)c;

从char到int(类似于VB Asc()):显式地将char类型转换为int: int i = (int)c;

or implicitly cast (promote): fi(char c) {i+= c;}

或隐式cast(提升):fi(char c) {i+= c;}

From int to char (analog of VB Chr()):

从int到char(模拟VB Chr()):

explicitly cast the int as an char: char c = (char)i, fc(int i) {(char)i};

显式地将int转换为char: char c = (char)i、fc(int i) {(char)i};

An implicit cast is disallowed, as an int is wider (has a greater range of values) than a char

隐式转换是不允许的，因为int比char更宽(有更大范围的值)。