c# - 带控制字符的字节数组到字符串

Question

所以我找到了一些例子，但没有一个是完全我想要的(尽管接近)

我正在寻找的例子

byte[] array = { 0x02, 0x64, 0x40, 0x40, 0x03 };
string text = SomeMagicalMethod(array);
//displays <STX>FOO<ETX>

有一次我有一本字典，其中包含不可打印的字符值和 <...> 内容，但是将这两个字符串组合起来让我头疼。我目前有这个，但它 ASCIIEncoding 取出所有控制字符。

public static void Add(this TextBox tb, byte[] array)
{
  string input = System.Text.ASCIIEncoding.ASCII.GetString(array);

  Regex.Replace( input     ,
                 @"\p{Cc}" ,
                 a => string.Format( "[{0:X2}]" , (byte)a.Value[0] )
               ) ;
  Add(tb, input);

}

public static void Add(this TextBox tb, string text)
{
  text += ENTER;
  tb.Dispatcher.Invoke( DispatcherPriority.Background,
    new Action(delegate() { tb.Text += text; })
    );
}

编辑使用 NUnit 我针对这些测试运行了已回答的代码。最后一个有一个值超出了 0x7F 的范围。虽然将使用它的代码不应该有那个，但安全总比抱歉好。

[TestFixture]
public class StringExtensionsTest
{
    [Test]
    public void SingleByteControlCharacterTest()
    {
        AssertSingleByte(0x00, "<NUL>"); AssertSingleByte(0x01, "<SOH>");
        AssertSingleByte(0x02, "<STX>"); AssertSingleByte(0x03, "<ETX>");
        AssertSingleByte(0x04, "<EOT>"); AssertSingleByte(0x05, "<ENQ>");
        AssertSingleByte(0x06, "<ACK>"); AssertSingleByte(0x07, "<BEL>");
        AssertSingleByte(0x08, "<BS>" ); AssertSingleByte(0x09, "<HT>" );
        AssertSingleByte(0x0A, "<LF>" ); AssertSingleByte(0x0B, "<VT>" );
        AssertSingleByte(0x0C, "<FF>" ); AssertSingleByte(0x0D, "<CR>" );
        AssertSingleByte(0x0E, "<SO>" ); AssertSingleByte(0x0F, "<SI>" );

        AssertSingleByte(0x10, "<DLE>"); AssertSingleByte(0x11, "<DC1>");
        AssertSingleByte(0x12, "<DC2>"); AssertSingleByte(0x13, "<DC3>");
        AssertSingleByte(0x14, "<DC4>"); AssertSingleByte(0x15, "<NAK>");
        AssertSingleByte(0x16, "<SYN>"); AssertSingleByte(0x17, "<ETB>");
        AssertSingleByte(0x18, "<CAN>"); AssertSingleByte(0x19, "<EM>" );
        AssertSingleByte(0x1A, "<SUB>"); AssertSingleByte(0x1B, "<ESC>");
        AssertSingleByte(0x1C, "<FS>" ); AssertSingleByte(0x1D, "<GS>" );
        AssertSingleByte(0x1E, "<RS>" ); AssertSingleByte(0x1F, "<US>" );
        AssertSingleByte(0x7F, "<DEL>");
    }
    private void AssertSingleByte(byte value, string expected)
    {
        byte[] array = new byte[]{value};
        var actual = array.asciiOctets2String();
        Assert.AreEqual(expected, actual, "Didn't print the epxected result");
    }

    [Test]
    public void SingleCharacterTest()
    {
        for (byte i = 0x20; i < 0x7F; i++) 
        {
            AssertSingleByte(i, char.ToString((char)i));
        }
    }

    [Test]
    public void SimpleTestTogether()
    {
        byte[] array = {0x02, 0x46,0x4F, 0x4F, 0x03};
        string expected = "<STX>FOO<ETX>";
        string actual = array.asciiOctets2String();
        Assert.AreEqual(expected, actual, "Simple test failed");
    }
    [Test]
    public void BigTest()
    {
        byte[] array = {
            0x00, 0x7F, 0x03, 0x52, 0x00, 0x00, 0x2F, 0x5F, 0x20, 0x0F, 0x43, 0x41, 0x52, 0x44, 0x48, 0x4F,
            0x4C, 0x44, 0x45, 0x52, 0x2F, 0x56, 0x49, 0x53, 0x41, 0x9F, 0x1F, 0x07, 0x30, 0x30, 0x30, 0x30,
            0x30, 0x30, 0x30};
        string expected = "<NUL><DEL><ETX>R<NUL><NUL>/_ <SI>CARDHOLDER/VISA?<US><BEL>0000000";
        string actual = array.asciiOctets2String();

        Assert.AreEqual(expected, actual, "BigTest Failed");
    }
}

Answer 1

你必须创建一个你想要的控制字符的表格，例如:

Dictionary<byte, string> controlCodes = new Dictionary<byte, string>
{
    { 0x00, "<NUL>" },
    { 0x01, "<SOH>" },
    { 0x02, "<STX>" },
    { 0x03, "<ETX>" },
    ...
}

您可以使用 this Wikipedia page构建完整列表。

那么构建你的就很简单了:

var output = String.Join(
    string.Empty, 
    array.Select(b => 
        controlCodes.ContainsKey(b) 
        ? controlCodes[b]
        : Encoding.ASCII.GetString(new[] { b })));

当然，这可以得到显着改善。这样的事情会更有效率:

string str = string.Empty;
int i = 0, j = 0;
while (i < array.Length && j > -1)
{
    j = Array.FindIndex(array, i, b => controlCodes.ContainsKey(b));
    if (j > -1) 
    {
        if (j > i)
        {
            str += Encoding.ASCII.GetString(array, i, j - i);
        }

        str += controlCodes[array[j]];
        i = j + 1;
    }
    else 
    {
        str += Encoding.ASCII.GetString(array, i, array.Length - i);
    }
}

return str;