使用跨浏览器兼容的 JavaScript 下载 PDF

Question

我可以在 Chrome 中使用 AngularJS 下载 PDF，但这似乎不适用于最新的 FireFox、Internet Explorer 11 或 Edge（假设它也不适用于 IE10），而且我知道IE9 需要垫片。如果有人有意见，不知道这是否是最好的垫片，但目前它似乎不起作用。我有一个应答式的试了一下blob，并arraybuffer只是在做一个差的情况下，它没有。

所有这些都与caniuse指示的使用 Blob URL相悖。任何人都可以在 IE9 及更高版本以及 FF 的最后几个版本中使用它，并且可以指出我做错了什么？

$http({
    url: '/api/v1/download',
    method: 'GET',
    responseType: 'blob' // or 'arraybuffer'
}).then(function (response) {

    // Use the Blob object to create an object URL to download the file
    var url = URL.createObjectURL(response.data);
    // var url = URL.createObjectURL(new Blob([response], {type: 'application/pdf'})); // arraybuffer version

    // Create an anchor to perform download, but don't append to the DOM
    anchor.href = downloadUrl;
    anchor.download = filename;
    anchor.target = '_blank';
    anchor.click();

    URL.revokeObjectURL(downloadUrl);            
    anchor = null;

}).catch(function (reason) {

    console.log('FAIL', reason);
});

更新

目前最好的（唯一的）答案适用于 IE10、11、Edge、FF，并继续与 Chrome 一起使用。如果有人有另一个 polyfill/shim/other/etc，IE9 将无法使用此解决方案，并且 Safari 不支持下载属性，因此所选答案中的解决方案在 SPA 中不起作用，因为它只是重定向当前页面所以在这两种情况下，我都只留下了 TODO 存根。

这是对已发布答案的更新，在评论中添加了更多信息供任何人使用或希望添加到 IE9 和 Safari 按预期工作：

    function performDownload(blob, filename) {

        // IE9 has no API for handling downloads using Blob objects, and doesn't support the download attribute
        if(isIE() == 9) {

            // TODO: polyfill/shim/other... change response type to?
        }
        // Only works for IE10 and up, including Edge
        else if (typeof window.navigator.msSaveBlob !== 'undefined') {

            // Provides a prompt to save the file to a location of users choice
            window.navigator.msSaveBlob(blob, filename);
        }
        // Browsers that adhere to current standards can implement downloads
        // using the Blob object with the download anchor attribute
        // ---
        // NOTE: Edge 13+ is compliant with both these standards, but Edge 12
        // does not support the download anchor attribute so all versions
        // have been grouped to use the propriety `msSaveBlob` method
        else {

            // Use the Blob object to create an object URL to download the file
            var URL = window.URL;
            var downloadUrl = URL.createObjectURL(blob);

            var anchor = document.createElement('a');

            if(angular.isDefined(anchor.download)) {

                anchor.href = downloadUrl;
                anchor.download = filename;
                anchor.target = '_blank';
                document.body.appendChild(anchor); // Required by Firefox
                anchor.click();

                // Release the existing object URL, and the anchor
                $timeout(function () {
                    URL.revokeObjectURL(downloadUrl);
                    document.body.removeChild(anchor);
                    anchor = null;
                }, 100);
            }
            else {

                // TODO: Safari does not support the download anchor attribute...
            }
        }
    }

Answer 1

我在 IE11 和 Chrome 中都成功地使用了它：

function saveBlob(response, contentType, filename) {
    let blob = new Blob([response.arrayBuffer()], { type: contentType });
    if (typeof window.navigator.msSaveBlob !== 'undefined') {
        // IE workaround
        window.navigator.msSaveBlob(blob, filename);
    } else {
        let URL = window.URL;
        let downloadUrl = URL.createObjectURL(blob);
        if (filename) {
            let a = document.createElement('a');
            if (typeof a.download === 'undefined') {
                window.location.href = downloadUrl;
            } else {
                a.href = downloadUrl;
                a.download = filename;
                document.body.appendChild(a);
                a.click();
            }
        } else {
            window.location.href = downloadUrl;
        }
        // cleanup
        setTimeout(function () { URL.revokeObjectURL(downloadUrl); }, 100); 
    }
}