CODEWITHSUNDEEP
c#cunicodecharacter-encoding
Jan3Sobieski
Jan3Sobieski

Reputation: 275

C# convert string Unicode to byte Ansi

google didnt help me such as i wanted so im writing post here. i have Unicode string in C# and C function (in dll) which want the char(ANSI)*. i try to do

string tmp = "ala ma kota";
unsafe
{
    fixed (byte* data = &tmp.ToCharArray()[0])
    {
        some_function(data);
    }
}

but i cannot convert directly without encoding. I try to use Encode class but without any effects. I know that, the some_function needs to be called with char pointer. Where it points to array of byte.

Upvotes: 2

Views: 10897

Answers (2)

Matthew Watson
Matthew Watson

Reputation: 109567

You don't need to do this explicitly yourself.

Instead, declare the C method using P/Invoke to accept a parameter of type string.

Then add to the P/Invoke declaration:

 [DllImport("YourDllName.dll", CharSet=CharSet.Ansi)]

The marshaller will then convert the string to ANSI for you.

Note that I'm assuming that the string is being passed TO the called function, so the parameter is NOT a pointer being used to return a new string FROM the called function.

See here for more details: http://msdn.microsoft.com/en-us/library/system.runtime.interopservices.dllimportattribute.charset.aspx

In fact, the default is CharSet.Ansi so you might only need to declare the parameter as string instead of byte* (or whatever you are using just now).

Upvotes: 6

SynerCoder
SynerCoder

Reputation: 12766

You should use the System.Text namespace:

string tmp = "ala ma kota";
unsafe
{
    fixed (byte* data = &System.Text.Encoding.ASCII.GetBytes(tmp)[0])
    {
        some_function(data);
    }
}

Upvotes: 3

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