How to create dll with ext.crates/dependencies?

[stukii]

I am creating a .dll that I am calling from c# with this in my cargo.toml

[lib]
name = "myLib"
crate-type = ["dylib"] 

my lib.rs contains

#![crate_type = "lib"]
#[no_mangle]

And I am perfectly able to call the function pub extern "C" fn myFunc.. from C#.

Until I add a extern crate like extern crate rand; Then it does no longer find the entry point on C#.

When only adding

[dependencies]
rand = "0.3"

to the cargo it does change the outcoming dll but it really only becomes unusable when adding the crate in the script.

What can I do to use external crates from my pinvoked rust-dlls?

[retep998]

Why do you specify the crate type both in your Cargo.toml and lib.rs, and why are they different? Also, both dylib and lib are the wrong crate type to have a .dll that can be used from C#. What you really want is the cdylib crate type.

Remember that the #[no_mangle] has to be attached directly to each function that you're exporting to be used from C#.

[stukii]

Thank you! I was using the no_mangle incorrectly. For anyone Interested how to make libs in rust and call from c#:

lib.rs

extern crate rand;
#[no_mangle]
pub extern "C" fn rsRandomI32() -> u32 {
    println!("entry rust");
    let rnum = rand::random::<u32>();
    println!("rnd : {}",rnum);
    rnum
}

cargo.toml

[dependencies]
rand = { git = "https://github.com/rust-lang-nursery/rand" }

[lib]
name = "myLibName"
crate-type = ["cdylib"] 

compile and use the .dll in c#

class Program
    {
        [DllImport(@"Path\myLibName.dll")]
        private static extern int rsRandomI32();
        static void Main(string[] args)
        {
            Console.WriteLine($"result in c#:{rsRandomI32()}");
        }
    }

[retep998]

Why does your Cargo.toml still have a crate type of dylib instead of cdylib?

[stukii]

Changed it, ty :)