What is the C# equivalent of ChrW(e.KeyCode)?

问题:

In VB.NET 2008, I used the following statement:

MyKeyChr = ChrW(e.KeyCode)

Now I want to convert the above statement into C#.

Any Ideas?

回答1:

Looks like the C# equivalent would be

var MyKeyChr = char.ConvertFromUtf32((int) e.KeyCode)

However, e.KeyCode does not contain a Unicode codepoint, so this conversion is meaningless.

回答2:

The quick-and-dirty equivalent of ChrW in C# is simply casting the value to char:

char MyKeyChr = (char)e.KeyCode;

The longer and more expressive version is to use one of the conversion classes instead, like System.Text.ASCIIEncoding.

Or you could even use the actual VB.NET function in C# by importing the Microsoft.VisualBasic namespace. This is really only necessary if you're relying on some of the special checks performed by the ChrW method under the hood, ones you probably shouldn't be counting on anyway. That code would look something like this:

char MyKeyChr = Microsoft.VisualBasic.Strings.ChrW(e.KeyCode);

However, that's not guaranteed to produce exactly what you want in this case (and neither was the original code). Not all the values in the Keys enumeration are ASCII values, so not all of them can be directly converted to a character. In particular, casting Keys.NumPad1 et. al. to char would not produce the correct value.

回答3:

The most literal way to translate the code is to use the VB.Net runtime function from C#

MyKeyChr = Microsoft.VisualBasic.Strings.ChrW(e.KeyCode);

If you'd like to avoid a dependency on the VB.Net runtime though you can use this trimmed down version

MyKeyChr = Convert.ToChar((int) (e.KeyCode & 0xffff));