VBには、charをASCII値に、またはその逆に変換するためのネイティブ関数が2つあります-Asc()およびChr()。
次に、C#で同等の機能を取得する必要があります。最善の方法は何ですか?
常にMicrosoft.VisualBasicへの参照を追加してから、まったく同じメソッド Strings.Chr および Strings.Asc を使用できます。
それはまったく同じ機能を取得する最も簡単な方法です。
Resharperを使用してこれらを取得しました。正確なコードは、マシン上でVB
/// <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"/> < 0 or > 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]);
}
リソースは保存されたエラーメッセージなので、どういうわけかあなたがそれらを無視する方法と、アクセスできない他の2つの方法は次のとおりです。
internal static Encoding GetFileIOEncoding()
{
return Encoding.Default;
}
internal static int GetLocaleCodePage()
{
return Thread.CurrentThread.CurrentCulture.TextInfo.ANSICodePage;
}
Strings.Ascは、ASCII 127文字のコード値を超える可能性のあるcharsに対する単純なC#キャストと同等ではありません。 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 は次のようになります:
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;
}
または、読み取り取引が必要な場合は、Microsoft.VisualBasic Assemblyへの参照を追加します。
Chr()には次を使用できます。
char chr = (char)you_char_value;
このメソッドをC#に追加します `
private int Asc(char String)
{
int int32 = Convert.ToInt32(String);
if (int32 < 128)
return int32;
try
{
Encoding fileIoEncoding = Encoding.Default;
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 num = bytes1[0];
bytes1[0] = bytes1[1];
bytes1[1] = num;
}
return (int)BitConverter.ToInt16(bytes1, 0);
}
catch (Exception ex)
{
throw ex;
}
}
`
Microsoft.VisualBasic.dllからAsc()関数を抽出しました。
public static int Asc(char String)
{
int num;
byte[] numArray;
int num1 = Convert.ToInt32(String);
if (num1 >= 128)
{
try
{
Encoding fileIOEncoding = Encoding.Default;
char[] str = new char[] { String };
if (!fileIOEncoding.IsSingleByte)
{
numArray = new byte[2];
if (fileIOEncoding.GetBytes(str, 0, 1, numArray, 0) != 1)
{
if (BitConverter.IsLittleEndian)
{
byte num2 = numArray[0];
numArray[0] = numArray[1];
numArray[1] = num2;
}
num = BitConverter.ToInt16(numArray, 0);
}
else
{
num = numArray[0];
}
}
else
{
numArray = new byte[1];
fileIOEncoding.GetBytes(str, 0, 1, numArray, 0);
num = numArray[0];
}
}
catch (Exception exception)
{
throw exception;
}
}
else
{
num = num1;
}
return num;
}
c#では、Char.ConvertFromUtf32ステートメントを使用できます
int intValue = 65; \\ Letter A
string strVal = Char.ConvertFromUtf32(intValue);
vBに相当
Dim intValue as integer = 65
Dim strValue As String = Char.ConvertFromUtf32(intValue)
Microsoft.VisualBasicの参照は不要