Simple Project

We can use tool to initial our HarmonyOS's project, and it's also possible for us to initial project with standard rust project.

Now, we will try to use standard rust project to build prebuild binary.

Init

Using cargo to initial a binary project.

cargo new hello --lib

Add dependencies

We need to add some dependencies, which provide useful functions.

cargo add napi-ohos napi-derive-ohos

cargo add napi-build-ohos --build

Setup binary type

There are many binary type for rust project, but now we use cdylib as final target. We need to add some config with Cargo.toml

# Cargo.toml

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

Setup build script

build.rs is a special file, that will execute before the project starts to bundle. We can use it to add some special logic to help us build the project.

🔆

More info about build script , you can find it with official book

At first, create a file build.rs in project's root folder, then we need to run setup, which is provided by napi-build-ohos, and the content is below here:

// build.rs
fn main () {
    napi_build_ohos::setup();
}

Our project may be like this:

.
├── Cargo.lock
├── Cargo.toml
├── build.rs
└── src
    └── lib.rs

Add napi method

Now we can write some napi method. For example, we can add a add method

use napi_derive_ohos::napi;

#[napi]
pub fn add(a: u32,b: u32) -> u32 {
    a + b
}

Build

Just run ohrs to build our project.

ohrs build

Then we can get the final prebuild binary and .d.ts file in hello/dist.