如何使用Blob下载Excel文件（使用fs.createReadStream进行utf-8编码？

Question

我使用excel4node成功创建了一个excel文件，并将其保存在服务器中，然后使用读取流将文件发送到客户端：

            res.set({
                'Content-Type': 'application/vnd.openxmlformats',
                'Content-Disposition': 'attachment; filename='+filename
            });

            // This line opens the file as a readable stream
            var readStream = fs.createReadStream(path+filename, {encoding: 'utf8'});

            // This will wait until we know the readable stream is actually valid before piping
            readStream.on('open', function () {
                // This just pipes the read stream to the response object (which goes to the client)
                readStream.pipe(res);
            });
            // This catches any errors that happen while creating the readable stream (usually invalid names)
            readStream.on('error', function(err) {
            res.end(err);
            });

[之后，我在浏览器中获取数据并使用Blob下载：

        var blob = new Blob([data], { type: 'application/vnd.openxmlformats' });
        var link = document.createElement('a');
        link.href = window.URL.createObjectURL(blob);
        link.download = "File.xlsx";

        document.body.appendChild(link);

        link.click();

        document.body.removeChild(link);

[当我尝试打开文件时，收到以下消息：

"Excel found unreadable content in 'File.xlsx'. Do you want to recover the contents of this workbook? If you trust the source of this workbook, click Yes"

并且如果我单击是，Excel会说该文件已损坏，无法恢复。

我想知道该怎么做才能从服务器中检索excel文件。

Answer 1

阅读了大量文章后，我在这里找到了答案How to save .xlsx data to file as a blob

我必须使用'base64-stream'和'excel4node'.write函数在后端将流编码为base64。>

wb.write(path+filename, function(err) {
                if (err) {
                    sails.log(err);
                } else {
                    // This line opens the file as a readable stream
                    var readStream = fs.createReadStream(path+filename);

                    // This will wait until we know the readable stream is actually valid before piping
                    readStream.on('open', function () {
                        // This just pipes the read stream to the response object (which goes to the client)
                        readStream.pipe(new Base64Encode()).pipe(res);
                    });
                    // This catches any errors that happen while creating the readable stream (usually invalid names)
                    readStream.on('error', function(err) {
                        res.end(err);
                    });
                }
            });
此后，我在浏览器中收到的数据如下：

.done(function(data){

      function s2ab(s) {
        var buf = new ArrayBuffer(s.length);
        var view = new Uint8Array(buf);
        for (var i=0; i!=s.length; ++i) view[i] = s.charCodeAt(i) & 0xFF;
        return buf;
      }

        var blob = new Blob([s2ab(atob(data))], { type: 'application/vnd.openxmlformats' });
        var link = document.createElement('a');
        link.href = window.URL.createObjectURL(blob);
        link.download = "ExcelFile.xlsx";

        document.body.appendChild(link);

        link.click();

        document.body.removeChild(link);
    })
问题出在编码中，即使您使用'utf16le'，Excel也无法读取该文件，所以这是我找到的最佳解决方案。