使用RSClientPrint直接打印本地RDLC报表

　　最近一个项目使用ReportViewer来呈现本地RDLC模块的报表，需要用户点击至少三次才能直正打印，用户感觉易用性很不好，需要我们修改。

　　经过网上查找相关资料，发现直接使用ACTIVEX控件RSClientPrint直接打印使用SQLSERVER报表服务的资料很多，也说的比较详细，可唯独没打印本地报表的相关内容，看来只能自已摸索了。

　　经过研究有关打印SQLSERVER报表服务的资料，特别是这篇文章：http://www.codeproject.com/KB/reporting-services/RsClientPrint.aspx，决下先写一个简单的HTML文 件测试一下：

代码

<! DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" >
< html  xmlns ="http://www.w3.org/1999/xhtml" >
< head >
     < title ></ title >
</ head >
< BODY  onload ="Print()" >
                 < OBJECT  ID ="RSClientPrint"
classid ="CLSID:5554DCB0-700B-498D-9B58-4E40E5814405"  CODEBASE ="/RSClientPrint-x86.cab"  VIEWASTEXT ></ OBJECT >
                 < script  type ="text/javascript"  language ="javascript" >
                     function  Print(oid,name) {
                         if  ( typeof  RSClientPrint.Print  ==   " undefined " ) {
                            alert( " Unable to load client print control. " );
                             return ;
                        }
                        RSClientPrint.MarginLeft  =   0 ;
                        RSClientPrint.MarginTop  =   0 ;
                        RSClientPrint.MarginRight  =   0 ;
                        RSClientPrint.MarginBottom  =   0 ;
                        RSClientPrint.PageHeight  =   296.926 ;
                        RSClientPrint.PageWidth  =   210.058 ;

                        RSClientPrint.Culture  =   2052 ;
                        RSClientPrint.UICulture  =   2052 ;
                        RSClientPrint.UseSingleRequest  =   true ;
                        RSClientPrint.UseEmfPlus  =   true ;
                        
                        RSClientPrint.Print( " http://localhost:2940/JDCJY/ReportHandler.ashx " ,  " oid= " + escape(oid) + " &name= " + escape(name),  " test " );
                    }
                 </ script >



                



                 </ BODY >
</ html >

 

　　然后实现ReportHandler.ashx 

代码

public   class  ReportHandler : IHttpHandler
    {

         public   void  ProcessRequest(HttpContext context)
        {

            Warning[] warningArray;
            HttpResponse response  =  context.Response;
            response.StatusCode  =   200 ;
            MemoryStream lastMemoryStream  =   null ;
            context.Response.BufferOutput  =   false ;
            context.Response.ContentType  =   null ;
            context.Response.Expires  =   - 1 ;

            var ds  =   new  DataSet();
            LocalReport localReport  =   new  LocalReport();
            localReport.ReportEmbeddedResource  =   string .Format( " {0}.rdlc " , context.Request.QueryString[ " name " ]);
            localReport.DataSources.Add( new  Microsoft.Reporting.WebForms.ReportDataSource( " ds " , ds));
            StringBuilder builder  =   new  StringBuilder( " <DeviceInfo> " );
            NameValueCollection requestParameters  =  context.Request.QueryString ;
             for  ( int  i  =   0 ; i  <  requestParameters.Count; i ++ )
            {
                 if  (requestParameters.Keys[i]  !=   null )
                {
                     if  (requestParameters.Keys[i].StartsWith( " rc: " , StringComparison.OrdinalIgnoreCase))
                    {
                        builder.AppendFormat( " <{0}>{1}</{0}> " , XmlConvert.EncodeName(requestParameters.Keys[i].Substring( 3 )), HttpUtility.HtmlEncode(requestParameters[i]));
                    }
                }
            }
            builder.Append( " </DeviceInfo> " );

            localReport.Render( " IMAGE " , builder.ToString(),  delegate ( string  name,  string  extension, Encoding encoding,  string  mimeType,  bool  willSeek)
            {
                 if  ( ! HttpContext.Current.Response.IsClientConnected)
                {
                     throw   new  HttpException( " Client disconnected " );
                }
                 if  (lastMemoryStream  !=   null )
                {
                     this .SendPrintStream(lastMemoryStream, response);
                    lastMemoryStream.Dispose();
                    lastMemoryStream  =   null ;
                }
                lastMemoryStream  =   new  MemoryStream();
                 return  lastMemoryStream;
            },  out  warningArray);
             this .SendPrintStream(lastMemoryStream, response);
            lastMemoryStream.Dispose();
             this .SendPrintStream( null , response);

             if  ( ! response.BufferOutput)
            {
                 string  a  =  context.Request.ServerVariables[ " SERVER_PROTOCOL " ];
                 if  ( string .Equals(a,  " HTTP/1.0 " , StringComparison.OrdinalIgnoreCase))
                {
                    context.Response.Close();
                }
            }

        }

         private   void  SendPrintStream(Stream stream, HttpResponse response)
        {
             int  length  =   0 ;
             if  (stream  !=   null )
            {
                length  =  ( int )stream.Length;
            }
             foreach  ( byte  num2  in  BitConverter.GetBytes(length))
            {
                response.OutputStream.WriteByte(num2);
            }
             if  (stream  !=   null )
            {
                stream.Position  =   0L ;
                StreamToResponse(stream, response);
                response.Flush();
            }
        }

         internal   static   void  StreamToResponse(Stream data, HttpResponse response)
        {
             int  count  =   0 ;
             byte [] buffer  =   new   byte [ 0x14000 ];
             while  ((count  =  data.Read(buffer,  0 ,  0x14000 ))  >   0 )
            {
                response.OutputStream.Write(buffer,  0 , count);
            }
        }



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

 

　　 再后经测试，直接加载上面的HTML页面就会提示直接打印。整个过程花了不少时间，有几个地方需要注意：

1.在服务器端生成DEVICEINFO时一定要使用上面所示的方法，我在测试过程中为了图简单，直接使用我原来在WINFORM写的一个代码，固定的DEVICEINFO信息，结果打印出来时始终会重复，不知道是怎么回事，经过使用Reflector反编译Microsoft.ReportViewer.WebForms，仔细这里面实现的报表相关服务，发现这点实现的区别，才最终搞定问题

2.服务器代码生成EMF流如果有问题，客户端会报一个错误代码，这时你很可能会以为是客户端的错误，我开始就是，因为报错误的速度太快了。我上网对对应问题代码的资料也没有明确结果，最后看还是直接跟踪代码试试，发现是服务器端代码有些问题。