每天进步一点点 C#动态生成Excel文件

Handler.ashx：生成动态Excel文件

public class Handler : IHttpHandler {
    public void ProcessRequest (HttpContext context) {
        context.Response.ContentType = "application/octet-stream";
        string filename = HttpUtility.UrlEncode("动态生成.xls");
        context.Response.AddHeader("Content-disposition",string.Format("attachment:filename={0}",filename));

       //谁能帮我解释一下上面加粗的这句代码，功能我知道，但需要详细一点的解释，先谢谢哈

    }
    public bool IsReusable {
        get {
            return false;
        }
    }
}