javascript - s3-amazon 图像 CORS 问题（仅在 5-8 小时后发生在少数浏览器中）

Question

目前，当我尝试从 s3 照片中获取5-8 小时前上传的图像时，我不知道为什么我一直遇到 CORS 错误。如果我在5-8 小时内收到它仍然可以！？这是我对 s3 aws 的配置：

<?xml version="1.0" encoding="UTF-8"?>
<CORSConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
    <CORSRule>
        <AllowedOrigin>*</AllowedOrigin>
        <AllowedMethod>GET</AllowedMethod>
        <AllowedMethod>HEAD</AllowedMethod>
        <AllowedMethod>POST</AllowedMethod>
        <AllowedMethod>PUT</AllowedMethod>
        <AllowedHeader>*</AllowedHeader>
    </CORSRule>
</CORSConfiguration>`

这是我尝试获取图像的javascript代码：

function getData(link){
	var image = new Image();
// 	image.crossOrigin = 'use-credentials';
	image.crossOrigin = 'anonymous';
	// create an empty canvas element
	var canvas = document.createElement("canvas"),
			canvasContext = canvas.getContext("2d");
	image.onload = function () {
		//Set canvas size is same as the picture
		canvas.width = image.width;
		canvas.height = image.height;
		// draw image into canvas element
		canvasContext.drawImage(image, 0, 0, image.width, image.height);
		// get canvas contents as a data URL (returns png format by default)
		var dataURL = canvas.toDataURL();
    document.getElementById("test").innerHTML = dataURL;
	};
	image.src = link;
}

getData("https://whammybar.s3.ap-southeast-1.amazonaws.com/duy-gmail-com/productImage/20181001/11bba32c-b276-47f4-b1fa-e87b53136bcc.jpg")

<span id="test"></span>

标签： javascriptgoogle-chromecanvasamazon-s3cors

Answer 1

问题不在于 S3 存储桶配置，而在于您如何渲染图像。

如果您打开您的图片链接，您可以清楚地看到它是可访问的。

您做错的是尝试在span元素中渲染图像，这就是为什么在您的示例中它将图像数据显示为 base64 字符串的原因。

只需将您span的元素更改为一个img元素，然后img.src将dataUrl

function getData(link){
	var image = new Image();
// 	image.crossOrigin = 'use-credentials';
	image.crossOrigin = 'anonymous';
	// create an empty canvas element
	var canvas = document.createElement("canvas"),
			canvasContext = canvas.getContext("2d");
	image.onload = function () {
		//Set canvas size is same as the picture
		canvas.width = image.width;
		canvas.height = image.height;
		// draw image into canvas element
		canvasContext.drawImage(image, 0, 0, image.width, image.height);
		// get canvas contents as a data URL (returns png format by default)
		var dataURL = canvas.toDataURL();
    document.getElementById("test").src = dataURL;
	};
	image.src = link;
}

getData("https://whammybar.s3.ap-southeast-1.amazonaws.com/duy-gmail-com/productImage/20181001/11bba32c-b276-47f4-b1fa-e87b53136bcc.jpg")

<img id="test">