rust - 如何获取当前时间(以毫秒为单位)？

Question

我如何像Java中那样以毫秒为单位获取当前时间？

System.currentTimeMillis()

Answer 1

从Rust 1.8开始，您不需要使用 crate 。相反，您可以使用 SystemTime 和 UNIX_EPOCH :

use std::time::{SystemTime, UNIX_EPOCH};

fn main() {
    let start = SystemTime::now();
    let since_the_epoch = start
        .duration_since(UNIX_EPOCH)
        .expect("Time went backwards");
    println!("{:?}", since_the_epoch);
}

如果您需要精确的毫秒数，则可以转换 Duration 。

rust 1.33

let in_ms = since_the_epoch.as_millis();

rust 1.27

let in_ms = since_the_epoch.as_secs() as u128 * 1000 + 
            since_the_epoch.subsec_millis() as u128;

rust 1.8

let in_ms = since_the_epoch.as_secs() * 1000 +
            since_the_epoch.subsec_nanos() as u64 / 1_000_000;