如何将SSRS中的报表转换成图片

在SSRS的程序框架下,一张报表有可能被多个客户端以不同的方式应用.譬如: Web页面可能需要HTML格式的报表,而打印时需要emf格式的报表.

在打印报表时,经常会先将它专换成emf格式的图片,再发送给打印客户端使用.那么如何实现之间的转换呢?

 1   
 2 'ReportingService是由web service的WSDL生成的代理类(Proxy)
 3 Public Class RTLReportService
 4         Inherits ReportingService
 5         Implements RTSystems.Framework.Reporting.IReportService
 6 
 7         Public Overloads Function Render(ByVal report As Framework.Reporting.IReport) As Byte()() Implements Framework.Reporting.IReportService.Render
 8           
 9 
10             Dim deviceInfo As String = Nothing
11             Dim format As String = "IMAGE"
12             Dim firstPage As [Byte]() = Nothing
13             Dim encoding As String = Nothing
14             Dim mimeType As String = Nothing
15             Dim warnings As Warning() = Nothing
16             Dim reportHistoryParameters As ParameterValue() = Nothing
17             Dim streamIDs As String() = Nothing
18             Dim pages As [Byte]()() = Nothing
19 
20             ' Build device info based on the start page 
21             deviceInfo = [String].Format("<DeviceInfo><OutputFormat>{0}</OutputFormat></DeviceInfo>", "emf")
22 
23             'Exectute the report and get page count. 
24             Try
25                 ' Renders the first page of the report and returns streamIDs for 
26                 ' subsequent pages 
27                 'firstPage = rs.Render(reportPath, format, Nothing, deviceInfo, Nothing, Nothing, _
28                 'Nothing, encoding, mimeType, reportHistoryParameters, warnings, streamIDs)
29 
30                 'Replacement code by sjs to handle parameters
31 
32                 Dim lstParams As New List(Of ParameterValue)
33 
34                 For Each param As RTSystems.Framework.Reporting.IReportParameter In report.Paramers
35                     Dim paramValue As New ParameterValue()
36                     paramValue.Name = param.Name
37                     paramValue.Value = param.Value
38                     lstParams.Add(paramValue)
39                 Next
40 
41                 Dim parameters() As ParameterValue = lstParams.ToArray()
42 
43            
44                 firstPage = Me.Render(report.ReportName, format, Nothing, deviceInfo, parameters, Nothing, _
45                 Nothing, encoding, mimeType, reportHistoryParameters, warnings, streamIDs)
46 
47 
48                 ' The total number of pages of the report is 1 + the streamIDs 
49                 m_numberOfPages = streamIDs.Length + 1
50                 pages = New [Byte](m_numberOfPages - 1)() {}
51 
52                 ' The first page was already rendered 
53                 pages(0) = firstPage
54 
55                 For pageIndex As Integer = 1 To m_numberOfPages - 1
56                     ' Build device info based on start page 
57                     deviceInfo = [String].Format("<DeviceInfo><OutputFormat>{0}</OutputFormat><StartPage>{1}</StartPage></DeviceInfo>", "emf", pageIndex + 1)
58                     'pages(pageIndex) = rs.Render(reportPath, format, Nothing, deviceInfo, Nothing, Nothing, _
59                     'Nothing, encoding, mimeType, reportHistoryParameters, warnings, streamIDs)
60                     pages(pageIndex) = Me.Render(report.ReportName, format, Nothing, deviceInfo, parameters, Nothing, _
61                     Nothing, encoding, mimeType, reportHistoryParameters, warnings, streamIDs)
62                 Next
63 
64             Finally
65 
66             End Try
67 
68             Return pages
69         End Function
70 
71     End Class