Convert keycode to char/string

问题

I'm trying to convert System.Windows.Forms.Keys to string/char using :

KeysConverter converter = new KeysConverter();
string text = converter.ConvertToString(keyCode);
Console.WriteLine(text);

But it returned "OemPeriod" for "." and "Oemcomma" for ",". Is there any way to get the exact character?

回答1:

This is probably what you really want (bit late, but hope this will help someone else), converting the keycode directly to the character the key prints.

First add this directive into your class:

[DllImport("user32.dll", CharSet = CharSet.Unicode)]
public static extern int ToUnicode(
    uint virtualKeyCode, 
    uint scanCode,
    byte[] keyboardState,
    StringBuilder receivingBuffer, 
    int bufferSize, 
    uint flags
);

Then use this if you just want to ignore the shift modifier

StringBuilder charPressed = new StringBuilder(256);
ToUnicode((uint)keyCode, 0, new byte[256], charPressed, charPressed.Capacity, 0);

Now just call charPressed.ToString() to get your key.

If you want the shift modifier, you can use something like this to make it easier

static string GetCharsFromKeys(Keys keys, bool shift)    
{
    var buf = new StringBuilder(256);
    var keyboardState = new byte[256];
    if (shift)
    {
        keyboardState[(int)Keys.ShiftKey] = 0xff;
    }
        ToUnicode((uint)keys, 0, keyboardState, buf, 256, 0);
        return buf.ToString();
}

回答2:

What you are trying to achieve is no trivial task by any means. There is the keyboard mapping (keyboard layout) that windows (for example) uses to translate keyboard keys to actual characters. Here is how I was able to achieve this:


    public string KeyCodeToUnicode(Keys key)
    {
        byte[] keyboardState = new byte[255];
        bool keyboardStateStatus = GetKeyboardState(keyboardState);

        if (!keyboardStateStatus)
        {
            return "";
        }

        uint virtualKeyCode = (uint)key;
        uint scanCode = MapVirtualKey(virtualKeyCode, 0);
        IntPtr inputLocaleIdentifier = GetKeyboardLayout(0);

        StringBuilder result = new StringBuilder();
        ToUnicodeEx(virtualKeyCode, scanCode, keyboardState, result, (int)5, (uint)0, inputLocaleIdentifier);

        return result.ToString();
    }

    [DllImport("user32.dll")]
    static extern bool GetKeyboardState(byte[] lpKeyState);

    [DllImport("user32.dll")]
    static extern uint MapVirtualKey(uint uCode, uint uMapType);

    [DllImport("user32.dll")]
    static extern IntPtr GetKeyboardLayout(uint idThread);

    [DllImport("user32.dll")]
    static extern int ToUnicodeEx(uint wVirtKey, uint wScanCode, byte[] lpKeyState, [Out, MarshalAs(UnmanagedType.LPWStr)] StringBuilder pwszBuff, int cchBuff, uint wFlags, IntPtr dwhkl);

回答3:

since there is "console-application" in your question tags, try this

     ConsoleKeyInfo input = Console.ReadKey(true);

     StringBuilder output = new StringBuilder(
                   String.Format("You pressed {0}", input.KeyChar));
     Console.WriteLine(output.ToString());

回答4:

Those are the correct and expected names for the comma and period keys on your keyboard. You can see that clearly from the documentation. The KeysConverter class is behaving as expected and as designed.

If you want to come up with a different name for those keys you can detect them and substitute the name that you desire to use. For instance:

string name;
switch (e.KeyCode)
{
    case Keys.Oemcomma:
        name = "Comma";
        break;
    case Keys.OemPeriod:
        name = "Period";
        break;
    default:
        name = (new KeysConverter()).ConvertToString(e.KeyCode);
        break;
}

来源：https://stackoverflow.com/questions/23170259/convert-keycode-to-char-string

标签

console-application