Question

使用MVC 4.0，我使用以下代码从ajax源（使用最新的firefox）从服务器创建下载文件：

如果输出涉及的是文本文件，如csv或txt文件，这可以正常工作，但是，当涉及zip或xlsx等文件时，似乎下载的文件与原始源不同（即在服务器是15K，但下载的是26K）

我已经苦苦挣扎了几天，请问是否有人应该说明为什么它适用于csv / text文件，而不是zip或xlsx文件？

非常感谢

控制器：

Public Function download(dataIn As myObject) As ActionResult
        'some processing
        'generated zip files and return with the full path            
        Dim zipFullPath = generateFiles(dataIn)

        Response.Clear()
        Response.ContentType = "application/zip"           
        Response.AddHeader("Content-Disposition", "attachment; filename=Out.zip")
        Dim fileLength = New IO.FileInfo(zipFullPath).Length
        'fileLength  reads about 15K of data
        Response.AddHeader("Content-Length", fileLength)
        Response.TransmitFile(zipFullPath)
        Response.End()
        Return View()
    End Function

JavaScript的：

$.ajax({
    type: "POST",
    url: "reports/download",
    data: jData,
    contentType: "application/json; charset=utf-8",
    success: function(response, status, xhr) {
        // check for a filename
        var filename = "";
        var disposition = xhr.getResponseHeader('Content-Disposition');
        if (disposition && disposition.indexOf('attachment') !== -1) {
            var filenameRegex = /filename[^;=\n]*=((['"]).*?\2|[^;\n]*)/;
            var matches = filenameRegex.exec(disposition);
            if (matches != null && matches[1]) filename = matches[1].replace(/['"]/g, '');
        }

        var type = xhr.getResponseHeader('Content-Type');
        var blob = new Blob([response], { type: type });

        if (typeof window.navigator.msSaveBlob !== 'undefined') {
            // IE workaround for "HTML7007: One or more blob URLs were revoked by closing the blob for which they were created. These URLs will no longer resolve as the data backing the URL has been freed."
            window.navigator.msSaveBlob(blob, filename);
        } else {
            var URL = window.URL || window.webkitURL;
            var downloadUrl = URL.createObjectURL(blob);

            if (filename) {
                // use HTML5 a[download] attribute to specify filename
                var a = document.createElement("a");
                // safari doesn't support this yet
                if (typeof a.download === 'undefined') {                
                    window.location = downloadUrl;
                } else {
                    a.href = downloadUrl;
                    a.download = filename;
                    document.body.appendChild(a);
                    a.click();

                    //Here is the problem, the original is about 15k,  
                    // but the download file is about 26K

                }
            } else {                    
                window.location = downloadUrl;
            }

            setTimeout(function () { URL.revokeObjectURL(downloadUrl); }, 100); // cleanup
        }
    },
    error: function (data) {
        alert('Error');
    }
});

Answer 1

目前jQuery ajax只能处理文本响应，这就是文本文件工作但二进制文件失败的原因。要从ajax下载非文本文件，请使用XMLHttpRequest对象并指定responseType，例如JDateChooser或blob。

arraybuffer

从ASP.NET下载（使用Blob进行AJAX下载）时，为什么文件不同？

1 个答案: