在 ASP.NET 中显示、导出和打印 Crystal Reports

• 下载源代码文件 - 71.7 Kb

引言

本文档的主要目的是在不出现任何错误的情况下显示报表。我被“登录失败错误”困扰了好几天，现在我终于有了一个可以无错误显示报表的代码。该代码还可以将报表导出为 .pdf、.xls、.rtf 和 .doc 格式。它还可以直接将报表打印到打印机。

使用代码

解压缩 crCodes.Zip，然后运行 crCode.vbproj 项目文件。

--- 或者 ----

将 Webform1.aspx 文件插入到您的现有项目中，然后将 crystalreport2.rpt 文件复制到您的项目中，然后开始使用该代码。

Webform1.aspx.vb 的完整源代码如下。只需像图像中所示那样设计表单，放置 Crystal Report Viewer 控件，并保留控件的默认名称

Imports CrystalDecisions.Shared
Imports System.IO

Public Class WebForm1
    Inherits System.Web.UI.Page

    Dim crReportDocument As CrystalReport2 = New CrystalReport2

    Protected WithEvents DropDownList1 As System.Web.UI.WebControls.DropDownList
    Protected WithEvents Button1 As System.Web.UI.WebControls.Button
    Protected WithEvents Label1 As System.Web.UI.WebControls.Label
    Protected WithEvents CrystalReportViewer1 As _
                             CrystalDecisions.Web.CrystalReportViewer
    Protected WithEvents Button2 As System.Web.UI.WebControls.Button

#Region " Web Form Designer Generated Code "
    'This call is required by the Web Form Designer.

    <System.Diagnostics.DebuggerStepThrough()> 
    Private Sub InitializeComponent()

    End Sub

    'NOTE: The following placeholder declaration is required 

    'by the Web Form Designer.

    'Do not delete or move it.

    Private designerPlaceholderDeclaration As System.Object

    Private Sub Page_Init(ByVal sender As System.Object,_ 
                        ByVal e As System.EventArgs) Handles MyBase.Init
        'CODEGEN: This method call is required by the Web Form Designer

        'Do not modify it using the code editor.

        InitializeComponent()


        ' this is the most IMPORTANT line of code

        ' if this line is not writen the 

        ' " LOGON FAILED" error starts displaying

        crReportDocument.SetDatabaseLogon("username",_ 
                                    "password", "sql-server", "database")

        ' the Above line works even if only username 

        ' and password is supplied as below


        'crReportDocument.SetDatabaseLogon("username",_

                                 "password") ', "sql-server", "database")


        ' this will hide the group tree

        CrystalReportViewer1.DisplayGroupTree = False

        CrystalReportViewer1.ReportSource = crReportDocument

        ' IF REPORT Uses Parameter's

        ' Pass Paramaters As Follows

        crReportDocument.SetParameterValue("city", "Mumbai")


        ' city = Parameter Name

        ' Mumbai = Parameter Value


        ' :-) thats ALL your Report Will Be displayed 

        ' now Without Logon Failed Error


        With DropDownList1.Items
            .Add("Rich Text (RTF)")
            .Add("Portable Document (PDF)")
            .Add("MS Word (DOC)")
            .Add("MS Excel (XLS)")
        End With
    End Sub

#End Region

    Private Sub Page_Load(ByVal sender As System.Object,_ 
                ByVal e As System.EventArgs) Handles MyBase.Load
        'Put user code to initialize the page here

    End Sub

    Sub ExportReport()

        Dim oStream As New MemoryStream ' // using System.IO


        'this contains the value of the selected export format.

        Select Case DropDownList1.SelectedItem.Text 

            Case "Rich Text (RTF)"
                '-----------------------------------------------------------


                oStream = crReportDocument.ExportToStream(_
                    CrystalDecisions.Shared.ExportFormatType.WordForWindows)
                Response.Clear()
                Response.Buffer = True
                Response.ContentType = "application/rtf"
                '------------------------------------------------------------


                '------------------------------------------------------------

            Case "Portable Document (PDF)"

                oStream = crReportDocument.ExportToStream(_
                    CrystalDecisions.Shared.ExportFormatType.PortableDocFormat)
                Response.Clear()
                Response.Buffer = True
                Response.ContentType = "application/pdf"
                '--------------------------------------------------------------


                '--------------------------------------------------------------

            Case "MS Word (DOC)"

                oStream = crReportDocument.ExportToStream(_
                        CrystalDecisions.Shared.ExportFormatType.WordForWindows)
                Response.Clear()
                Response.Buffer = True
                Response.ContentType = "application/doc"
                '---------------------------------------------------------------


                '---------------------------------------------------------------

            Case "MS Excel (XLS)"

                oStream = crReportDocument.ExportToStream(_
                                 CrystalDecisions.Shared.ExportFormatType.Excel)
                Response.Clear()
                Response.Buffer = True
                Response.ContentType = "application/vnd.ms-excel"
                '---------------------------------------------------------------

        End Select 'export format

        Try
            Response.BinaryWrite(oStream.ToArray())
            Response.End()
        Catch err As Exception
            Response.Write("< BR >")
            Response.Write(err.Message.ToString)
        End Try
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, _
                          ByVal e As System.EventArgs) Handles Button2.Click
        ExportReport()
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, _
                          ByVal e As System.EventArgs) Handles Button1.Click
        crReportDocument.SetDatabaseLogon("USER", _
                                "PASSWORD", "SQL-SERVER", "DATABASE")
        crReportDocument.PrintToPrinter(1, False, 0, 0)
    End Sub
End Class

为什么会生成“登录失败错误”？

“登录失败”错误基本上是由于在显示报表时，它会尝试登录到数据库服务器。即使您在设计时选择了服务器，报表在显示或导出或打印时仍然需要服务器名称。

消除此错误的编码行是

crReportDocument.SetDatabaseLogon("USER", "PASSWORD", "SQL-SERVER", "DATABASE")

或者也可以使用

crReportDocument.SetDatabaseLogon("USER", "PASSWORD")