查看完整源代码 或 在线查看编译后的示例

这是 `#[wasm_bindgen]` 的“你好，世界！”示例，展示了如何设置项目、将函数导出到 JS、从 JS 调用它，然后在 Rust 中调用 `alert` 函数。

`Cargo.toml` 将 `wasm-bindgen` crate 列为依赖项。

值得注意的是 `crate-type = ["cdylib"]`，它在当今的 wasm 最终制品中被广泛使用。

[package]
name = "hello_world"
version = "0.1.0"
authors = ["The wasm-bindgen Developers"]
edition = "2018"
rust-version = "1.57"

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

[dependencies]
wasm-bindgen = "0.2.92"

在这里，我们定义了 Rust 的入口点，并调用了 `alert` 函数。

# #![allow(unused_variables)]
#fn main() {
use wasm_bindgen::prelude::*;

#[wasm_bindgen]
extern "C" {
    fn alert(s: &str);
}

#[wasm_bindgen]
pub fn greet(name: &str) {
    alert(&format!("Hello, {}!", name));
}

#}

我们的 JS 入口点非常小！

import { greet } from './pkg';

greet('World');

注意：此示例需要 Webpack，如果您对不使用 JS 打包器的选项感兴趣，请查看其他示例。

最后，这是此项目的 Webpack 配置和 `package.json`

webpack.config.js

const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const webpack = require('webpack');
const WasmPackPlugin = require("@wasm-tool/wasm-pack-plugin");

module.exports = {
    entry: './index.js',
    output: {
        path: path.resolve(__dirname, 'dist'),
        filename: 'index.js',
    },
    plugins: [
        new HtmlWebpackPlugin(),
        new WasmPackPlugin({
            crateDirectory: path.resolve(__dirname, ".")
        }),
        // Have this example work in Edge which doesn't ship `TextEncoder` or
        // `TextDecoder` at this time.
        new webpack.ProvidePlugin({
          TextDecoder: ['text-encoding', 'TextDecoder'],
          TextEncoder: ['text-encoding', 'TextEncoder']
        })
    ],
    mode: 'development',
    experiments: {
        asyncWebAssembly: true
   }
};

package.json

{
  "scripts": {
    "build": "webpack",
    "serve": "webpack serve"
  },
  "devDependencies": {
    "@wasm-tool/wasm-pack-plugin": "1.5.0",
    "html-webpack-plugin": "^5.3.2",
    "text-encoding": "^0.7.0",
    "webpack": "^5.49.0",
    "webpack-cli": "^4.7.2",
    "webpack-dev-server": "^4.15.1"
  }
}