在C# .net MVC中使用ajax下载文件

<button id="downloadBtn">下载文件</button>

<script>
    $(document).ready(function() {
        $('#downloadBtn').click(function() {
            $.ajax({
                url: '/Controller/DownloadFile',
                type: 'GET',
                success: function(data) {
                    // 创建临时下载链接
                    var blob = new Blob([data]);
                    var downloadUrl = URL.createObjectURL(blob);
                    
                    // 创建隐藏的<a>标签并模拟点击
                    var a = document.createElement('a');
                    a.href = downloadUrl;
                    a.download = 'filename.pdf';
                    a.style.display = 'none';
                    document.body.appendChild(a);
                    a.click();
                    
                    // 清理临时下载链接
                    URL.revokeObjectURL(downloadUrl);
                }
            });
        });
    });
</script>

public class Controller : Controller
{
    public ActionResult DownloadFile()
    {
        // 获取要下载的文件路径或数据
        string filePath = "path/to/file.pdf";
        
        // 读取文件数据
        byte[] fileData = System.IO.File.ReadAllBytes(filePath);
        
        // 设置响应头
        Response.ContentType = "application/pdf";
        Response.AppendHeader("Content-Disposition", "attachment; filename=filename.pdf");
        
        // 写入响应流
        Response.BinaryWrite(fileData);
        Response.Flush();
        Response.End();
        
        return null;
    }
}