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Ricardo Soria
Asked: 2020-10-30 13:36:45 +0800 CST 2020-10-30 13:36:45 +0800 CST

Not downloading file in browser using OutputStream.Write in ASP.NET WebService C#

  • 772

I need to download a file located in the App_Data folder of my project, all permissions are granted, I have the following code to download an .xlsx file by calling a WebService in C#, the result of the process does not throw an error, but it does not download the file in the explorer and in the preview when inspecting the process shows unknown characters.

AJAX Jquery code:

function DOWNLOAD_EXCEL_SERVICES() {

    $.ajax({
        type: 'POST',
        url: '../WebServices/getJSON.asmx/DOWNLOAD_EXCEL_SERVICES',
        contentType: 'application/x-msexcel',
        success: OnSuccess,
        error: function (xhr, status, error) {
            var err = eval("(" + xhr.responseText + ")");
            alert(err.Message);
        }
    });

    function OnSuccess() {
        console.log("donloading-services");
    }

}

WebService C# code:

    [WebMethod]
    public void DOWNLOAD_EXCEL_SERVICES()
    {
        var path = Server.MapPath("~/App_Data//");
        string filename = "SERVICES.xlsx";
        System.Web.HttpResponse Response = System.Web.HttpContext.Current.Response;
        byte[] Content = File.ReadAllBytes(path + "SERVICES.xlsx");
        Response.ContentType = "application/x-msexcel";
        Response.AddHeader("content-disposition", "attachment; filename=\"" + filename + "\"");
        Response.BufferOutput = true;
        Response.OutputStream.Write(Content, 0, Content.Length);
        Response.Flush();
}

Output of Process inspecting in Chrome:

enter image description here

enter image description here

Additionally if I use Response.End()instead of Response.flush()just check "Proces was being aborted", even though I use a try-catch structure I get the same result, it doesn't drop the file.

c#

2 Answers

  1. The problem is that you are doing an AJAX post, so the file is sent to the stream that receives your $.ajax request.

    In other words, so that you can download it you should make a link that goes directly to the web service, or from JavaScript you could do it like this:

    function DOWNLOAD_EXCEL_SERVICES() {
    window.location = '../WebServices/getJSON.asmx/DOWNLOAD_EXCEL_SERVICES';
}

    I hope it helps you.

    Luck!

    • 1
  2. Best Answer

    Completing Gustavo Cantero 's answer, my Javascript code looks like this:

    function DOWNLOAD_EXCEL_SERVICES() {
    window.location.href = '../WebServices/getJSON.asmx/DOWNLOAD_EXCEL_SERVICES';
}

    and finally looking for similar problems, for the request to the WebService to work directly you have to add the following tags to the file Web.config:

    <configuration>

    <system.web>
    <webServices>
        <protocols>
            <add name="HttpGet"/>
            <add name="HttpPost"/>
        </protocols>
    </webServices>
    </system.web>

</configuration>

    My Web Service remains unedited; solved in my case, thanks.

    • 0