所以在我的应用中，用户可以上传 1 到 3 张图片，当他点击保存按钮时，我将它们上传到 firebase。
到目前为止，这是我的代码，我知道它很糟糕，我正在寻找一种使其高效的方法。
if (img1) {
uploadImage(img1, 'image/jpeg', 'imageOne', uuid)
.then(() => {
console.log('Image 1 was uploaded succesfully');
}).catch(err => console.log(err));
}
if (img2) {
uploadImage(img2, 'image/jpeg', 'imageTwo', uuid)
.then(() => {
console.log('Image 2 was uploaded succesfully');
}).catch(err => console.log(err));
}
if (img3) {
console.log('there is img3')
uploadImage(img3, 'image/jpeg', 'imageThree', uuid)
.then(() => {
console.log('Image 3 was uploaded succesfully');
}).catch(err => console.log(err));
}
问题是我想在上传完成后将用户重定向到主页。但是很难决定重定向代码应该放在哪里。
我考虑过像这样嵌套 if 语句:
if (img1) {
uploadImage(img1, 'image/jpeg', 'imageOne', uuid)
.then(() => {
console.log('Image 1 was uploaded succesfully');
if (img2) {
uploadImage(img2, 'image/jpeg', 'imageTwo', uuid)
.then(() => {
console.log('Image 2 was uploaded succesfully');
}).catch(err => console.log(err));
}
}).catch(err => console.log(err));
}
但是如果用户只上传了 img2 而不是 img1 呢？那么 img2 将永远不会被上传。我怎样才能改进我的代码？
最佳答案
你可以使用 Promise.all
let promises = [];
if (img1) {
promises.push(uploadImage(img1, 'image/jpeg', 'imageOne', uuid);
}
if (img2) {
promises.push(uploadImage(img2, 'image/jpeg', 'imageTwo', uuid);
}
// etc...
Promise.all(promises).then(() => {console.log("All requests are done")})
关于javascript - 如何处理多个异步请求？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/45596384/