Node.js 注意NodeJS中线程循环的结束

我必须在我的NodeJS应用程序中使用

我做循环。因此，我有两个选择：

备选案文1：

async function makePngScreenshot(url, meterId, filename) {
    axios.get(url, null); // Make the request to generate html page
    await new Pageres({delay: 2, filename: filename})
        .src(url, ['1300x650'], {crop: true})
        .dest("public/images/" + operation.data.name + "/" + yearAndMonthFolder + "/" + meterId
        )
        .run();
}

然后称之为：

for (let firstDay = monday; firstDay < lastDay; firstDay.add(7, "day")) {
    await makePngScreenshot(url, id, filename);
}

并称之为：

for (let firstDay = monday; firstDay < lastDay; firstDay.add(7, "day")) {
        makePngScreenshot(url, id, filename);
    }
console.log("done")

for（让firstDay=monday；firstDay

这个方法要快得多，我想使用它，但我不知道如何在所有截图生成之后打印

done

，现在，它在生成之前打印

如何知道所有线程的结束？

可用于此目的。您需要从makePngScreenShot返回一个承诺，这是一个较小的修改，还需要从异步函数调用makePngScreenShot

这看起来是这样的：

async function makePngScreenshot(url, meterId, filename) {
    await axios.get(url, null); // Make the request to generate html page
    return new Pageres({delay: 2, filename: filename})
        .src(url, ['1300x650'], {crop: true})
        .dest("public/images/" + operation.data.name + "/" + yearAndMonthFolder + "/" + meterId
        )
        .run();
}

async function makeScreenshots() {
    let promises = []; 
    for (let firstDay = monday; firstDay < lastDay; firstDay.add(7, "day")) {
        promises.push(makePngScreenshot(url, id, filename));
    }
    // Wait for all promises to resolve
    await Promise.all(promises);
    console.log("done")
}

异步函数makePngScreenshot（url、meterId、filename）{
wait axios.get（url，null）；//请求生成html页面
返回新页面（{延迟：2，文件名：filename}）
.src（url，['1300x650']，{crop:true}）
.dest（“public/images/”+operation.data.name+“/”+yearAndMonthFolder+“/”+meterId
)
.run（）；
}
异步函数makeScreenshots（）{
让承诺=[]；
for（让firstDay=monday；firstDay

太棒了！祝项目顺利！

async function makePngScreenshot(url, meterId, filename) {
    await axios.get(url, null); // Make the request to generate html page
    return new Pageres({delay: 2, filename: filename})
        .src(url, ['1300x650'], {crop: true})
        .dest("public/images/" + operation.data.name + "/" + yearAndMonthFolder + "/" + meterId
        )
        .run();
}

async function makeScreenshots() {
    let promises = []; 
    for (let firstDay = monday; firstDay < lastDay; firstDay.add(7, "day")) {
        promises.push(makePngScreenshot(url, id, filename));
    }
    // Wait for all promises to resolve
    await Promise.all(promises);
    console.log("done")
}