silverlight 导出Excel

一、前因

      因为项目中需要在silverlight 中导出Excel文件，所以就在琢磨这个事情了，开始时候的想法是能不能通过js 导出excel，在网上查了资料，试了所有找到的方法，可惜没有一个成功的。想不出其他办法，只能绕着走了，可能有点蠢，呵呵。不知道大家是怎么解决的，我把自己的发出来，抛砖引玉，不恰当的地方欢迎指出。

 

二、具体实现

      整个解决方案包括以下几个项目，如图：

 

其中的BLL，Enity项目只是提供一个示例，没多大用处。ExcelExport项目中的SearchParam.cs文件中包含查询参数类，以及导航处理类。导航处理类主要是根据传入的参数集合、导出类型生成查询字符串，并传给Export.ashx处理。代码如下：

/// <summary>
    /// 查询参数类
    /// </summary>
    public class SearchParam
    {
        
        public string Value { get; set; }
        
        public object Name { get; set; }

        public SearchParam(string value, string name)
        {
            Value = value;
            Name = name;
        }

        public override string ToString()
        {
            return Value + "_" + Name;
        }
    }

    /// <summary>
    /// 导出处理
    /// </summary>
    public class ExportHandle
    {
        /// <summary>
        /// 获取查询字符串
        /// </summary>
        /// <param name="searchParams">参数集合</param>
        /// <returns></returns>
        private static string GetQueryString(IEnumerable<SearchParam> searchParams)
        {
            StringBuilder builder = new StringBuilder("condition=");
            foreach (var param in searchParams)
            {
                builder.Append(param.ToString() + " ");
            }
            return builder.ToString().TrimEnd();
        }

        /// <summary>
        /// 导出处理 
        /// </summary>
        /// <param name="paramCollection">参数集合</param>
        /// <param name="action">导出类型</param>
        public static void Action(SearchParam[] paramCollection, string action)
        {
            string paramString = GetQueryString(paramCollection);
            var uriInfo = HtmlPage.Document.DocumentUri;
            var path = uriInfo.AbsoluteUri.Replace(uriInfo.AbsolutePath, "");
            string uriString = string.Concat(path, "/Export.ashx?", "action=", action, "&", paramString);
            HtmlPage.Window.Navigate(new System.Uri(uriString, UriKind.Absolute));
        }
    }

       在项目ExcelExport.Web中增加了一个导出处理，用来将传入的参数进行处理，并发送到WCF服务获取导出信息，然后以excel格式返回。其中存在一个正则表达式处理类，用来对查询字符串处理返回查询参数集合。代码如下：

/// <summary>
    /// $codebehindclassname$ 的摘要说明
    /// </summary>
    [WebService(Namespace = "http://tempuri.org/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    public class Export : IHttpHandler
    {

        #region IHttpHandler接口

        public void ProcessRequest(HttpContext context)
        {            
            var queryString = context.Request.QueryString;
            string action = queryString["action"];
            string condition = queryString["condition"];
            var searchParams = GetParams(condition);
            ExportClient client = new ExportClient("WSHttpBinding_IExport");
            string content=client.GetExportString(searchParams, action);
            ExportToExcel(context.Response, content,action);
        }

        public bool IsReusable
        {
            get
            {
                return true;
            }
        }

        #endregion


        #region 
        private SearchParam[] GetParams(string condition)
        {
            string pattern = @"\b(\S+)_(\S+)\b";
            IRegular regular = new Regular();
            RegularInfo info = new RegularInfo(condition, pattern, RegexOptions.IgnoreCase);
            var matchs = regular.Filter(info);
            SearchParam[] searchParams=new SearchParam[matchs.Length];
            int i = 0; SearchParam param;
            foreach (Match match in matchs)
            {
                param = new SearchParam();
                param.Name = match.Groups[1].Value;
                param.Value = match.Groups[2].Value;
                searchParams[i] = param;
                i++;
            }
            return searchParams;
        }

        protected void ExportToExcel(HttpResponse response,string content,string action)
        {
            response.Clear();
            response.Buffer = true;
            response.Charset = "GB2312";
            //page.Response.Charset = "UTF-8";
            response.AppendHeader("Content-Disposition", "attachment;filename=" + action + ".xls");
            response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");//设置输出流为简体中文
            response.ContentType = "application/ms-excel";//设置输出文件类型为excel文件。             
            response.Write(content);
            response.End();

        }
        #endregion
    }

正则表达式处理代码：

public interface IRegular
    {
        Match[] Filter(RegularInfo info);
    }

    /// <summary>
    /// 正则表达式处理
    /// </summary>
    public class Regular:IRegular
    {

        #region IRegular 成员

        public Match[] Filter(RegularInfo info)
        {
            var matchCollection = Regex.Matches(info.Source, info.Pattern, info.Options);
            Match[] result = new Match[matchCollection.Count];
            int i = 0;
            foreach (Match match in matchCollection)
            {
                result[i] = match;
                i++;
            }
            return result;
        }

        #endregion
    }

    /// <summary>
    /// 正则表达式信息
    /// </summary>
    public class RegularInfo
    {
        public string Source { get; set; }

        public string Pattern { get; set; }

        public RegexOptions Options { get; set; }

        public RegularInfo(string source, string pattern, RegexOptions options)
        {
            Source = source;
            Pattern = pattern;
            Options = options;
        }
    }

       项目ExportConfig中包括的内容是最重要的，主要分为接口、默认实现、导出处理、查询实体类四部分。接口分别为（1）IExportContent存在两个方法，Print()用来返回一行中各列的值，GetFormat() 返回单元格的样式，这里的样式必须为css样式；（2）IContentIterator内容迭代接口；（3）IExportFactory存在CreateHead,CreateContent两个方法，分别用来返回表头，表内容迭代。默认实现为：ExportContent，ContentAggregate，ContentIterator，ExportAbstractFactory。导出处理放在ExportHandle类。

接口代码：

    /// <summary>
    /// 内容迭代接口
    /// </summary>
    public interface IContentIterator
    {
        bool HasNext();
        IExportContent Next();
    }


    /// <summary>
    /// 内容接口
    /// </summary>
    public interface IExportContent
    {
        string[] Print();
        string GetFormat();
    }


    /// <summary>
    /// 表信息工厂接口
    /// </summary>
    public interface IExportFactory
    {
        IExportContent  CreateHead();
        IContentIterator CreateContent(SearchCollection condition);
    }

导出处理类：

 public class ExportHandle
    {
        private IExportFactory factory;
        public ExportHandle(IExportFactory factory)
        {
            this.factory = factory;
        }

        public string GetExportString(SearchCollection condition)
        {
            var head = factory.CreateHead();
            StringBuilder build = new StringBuilder("<table>");            
            AppandString(head, build);
            var iterator = factory.CreateContent(condition);
            IExportContent item;
            while (iterator.HasNext())
            {
                item = iterator.Next();
                AppandString(item, build);
            }
            build.Append("</table>");
            return build.ToString();
        }

        private void AppandString(IExportContent item,StringBuilder build)
        {
            
            string format = item.GetFormat(), value;
            bool hasFormat = !string.IsNullOrEmpty(format);
            build.Append("<tr>");
            var stringList = item.Print();                        
            foreach (var str in stringList)
            {
                if (hasFormat)
                {
                    value = string.Format("<td style=\"border-color:Gray; border-thin;border-style:ridge;{0}\">{1}</td>", format, str);
                }
                else
                {
                    value = string.Format("<td style=\"border-color:Gray; border-thin;border-style:ridge\">{0}</td>", str);
                }
                build.Append(value);
            }
            build.Append("</tr>");            
        }
    }

         最后一个项目ExportService 是用来提供WCF服务的，这里还存在一个设置，可以在web.config中添加导出的类名，以及程序集名称 ，如图：

 

获取配置信息后，通过反射创建实例。然后将查询参数、实例传给导出处理类进行操作。如下代码所示：

    [ServiceBehavior]
    [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
    public class Export : IExport
    {

        #region IExport 成员        
        public string GetExportString(SearchParam[] paramCollection, string action)
        {
            string[] infos = ConfigurationSettings.AppSettings[action].Split('|');
            SearchCollection condition = null;
            if (paramCollection != null)
            {
                condition = new SearchCollection();
                foreach (var param in paramCollection)
                {
                    condition.Add(param);
                }
            }
            IExportFactory instance = (IExportFactory)CommonHelp.CreateInstance(infos[1], infos[0], null);
            ExportHandle handle = new ExportHandle(instance);
            return handle.GetExportString(condition);
        }
        #endregion
    }

    public class CommonHelp
    {
        public static object CreateInstance(string type, string assembly, object[] args)
        {
            return Assembly.Load(assembly).CreateInstance(type, true, BindingFlags.Default, null, args, null, null);
        }  
    }

  

      另外，WCF调用可能存在跨域问题，在IIS网站根目录下放这个clientaccesspolicy.xml文件就OK了。第一次写可能有点乱，觉得还点用，就将就着看下吧，呵呵。完整的Demo下载：

/Files/WGZ_Home/ExcelExport.rar 

——————————————————————————————————————————————————————————————————————————————————

     经（笨笨的猪）朋友的提醒，现在把handle去掉了，并进行了一些小的修改，silverlight直接引用WCF服务，并返回byte[]，然后通过SaveDialog保存。修改后的关于silverlight的

处理代码如下：

        private void click_Click(object sender, RoutedEventArgs e)
        {
            
            ObservableCollection<SearchParam> paramCollection = new ObservableCollection<SearchParam>();
            var param=new SearchParam();
            param.Name="2";
            param.Value="2";
            paramCollection.Add(param);
            SaveFileDialog dialog=new SaveFileDialog();
            ExportHandle("ATPExport", paramCollection, dialog);
           
        }

        public static void ExportHandle(string action,ObservableCollection<ExeclExport.Export.SearchParam> paramCollection,SaveFileDialog dialog)
        {            
            try  
            {                
                dialog.DefaultExt = ".txt";   
                dialog.Filter = "Excel Files|*.xls|Log Files|*.doc";   
                dialog.FilterIndex = 1;   
            }   
            catch ( Exception ex )   
            {   
                HtmlPage.Window.Alert(ex.Message);
                return;
            }
            bool? dialogResult = dialog.ShowDialog();   
            if ( dialogResult == true )   
            {  
                Export.ExportClient client = new ExeclExport.Export.ExportClient();
                client.GetExportStringCompleted += delegate(object sender, ExeclExport.Export.GetExportStringCompletedEventArgs e)
                {
                     if(e.Error==null)
                     {
                         using ( Stream fs =dialog.OpenFile() )   
                         {
                             var resultBytes = e.Result;
                             fs.Write(resultBytes, 0, resultBytes.Length);
                             fs.Close();   
                             HtmlPage.Window.Alert("保存成功");                            
                         }                                          
                         return;
                     }
                     client.CloseAsync();
                     HtmlPage.Window.Alert(e.Error.Message);
                };


                client.GetExportStringAsync(paramCollection, action);
            }
        }

完整Demo如下：/Files/WGZ_Home/ExcelExport.rar