FileUpload

protected void Button1_Click(object sender, EventArgs e)
    {
        if (FileUpload1.HasFile)
        {
            string fileContentType = FileUpload1.PostedFile.ContentType;
            if (fileContentType == "image/bmp" || fileContentType == "image/gif" || fileContentType == "image/pjpeg")
            {
                string name = FileUpload1.PostedFile.FileName;                  // 客户端文件路径

                FileInfo file = new FileInfo(name);
                string fileName = file.Name;                                    // 文件名称
                string fileName_s = "s_" + file.Name;                           // 缩略图文件名称
                string fileName_sy = "sy_" + file.Name;                         // 水印图文件名称（文字）
                string fileName_syp = "syp_" + file.Name;                       // 水印图文件名称（图片）
                string webFilePath = Server.MapPath("file/" + fileName);        // 服务器端文件路径
                string webFilePath_s = Server.MapPath("file/" + fileName_s);　　// 服务器端缩略图路径
                string webFilePath_sy = Server.MapPath("file/" + fileName_sy);　// 服务器端带水印图路径(文字)
                string webFilePath_syp = Server.MapPath("file/" + fileName_syp);　// 服务器端带水印图路径(图片)
                string webFilePath_sypf = Server.MapPath("file/shuiyin.jpg");　// 服务器端水印图路径(图片)

                if (!File.Exists(webFilePath))
                {
                    try
                    {
                        FileUpload1.SaveAs(webFilePath);                                // 使用 SaveAs 方法保存文件
                        AddShuiYinWord(webFilePath, webFilePath_sy);
                        AddShuiYinPic(webFilePath, webFilePath_syp, webFilePath_sypf);
                        MakeThumbnail(webFilePath, webFilePath_s, 130, 130, "Cut");     // 生成缩略图方法
                        Label1.Text = "提示：文件“" + fileName + "”成功上传，并生成“" + fileName_s + "”缩略图，文件类型为：" + FileUpload1.PostedFile.ContentType + "，文件大小为：" + FileUpload1.PostedFile.ContentLength + "B";
                    }
                    catch (Exception ex)
                    {
                        Label1.Text = "提示：文件上传失败，失败原因：" + ex.Message;
                    }
                }
                else
                {
                    Label1.Text = "提示：文件已经存在，请重命名后上传";
                }
            }
            else
            {
                Label1.Text = "提示：文件类型不符";
            }
        }
    }