asp.net MVC。 没有重定向就不能使用void方法

Question

I have a form and void post method.

<form id="frm_loadFile" action="/Home/LoadFileWhithChanges" enctype="multipart/form-data" method="post" style="margin-top: 40px;">
                <input type="file" style="width: 100%;" name="upload" value="Choose file"><br><br>
                <input style="width: 115px;" type="submit" value="Upload">
</form>

    [HttpPost]
    public void LoadFileWhithChanges(HttpPostedFileBase upload)
    {
                if (upload == null)
                {
                    Response.Write(@"<script language='javascript'>alert('No file')</script>");
                    Response.Flush();
                    Response.End();

                    return;
                }
                else
                {
                   //...
                   Response.Write(@"<script language='javascript'>alert('All done')</script>");
                    Response.Flush();
                    Response.End();

                    return;
                }
}

But when it calls Response.Write after alert my page redirects

I want stay on this page after response.write/ How can I do this?

Answer 1

You are posting a form, and receive a response. It doesn't matter that your action is void . The browser doesn't care how the response was generated on the server. It's only course of action is to display the result. If you want to stay in the same page, you should either:

1. return the same page from the action
2. post the form in AJAX, which, in the case of posting a file, requires a special technique, involving iframes. You can look it up on the web.