水晶报表参数编程示例代码

    Imports CrystalDecisions.Shared
    Imports CrystalDecisions.CrystalReports.Engine

    Private Const RPT_NAME As String = "CustomerOrders.rpt"
    Private Const PARAMETER_FIELD_NAME As String = "CustomerID"

    Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        '在此处放置初始化页的用户代码

        ' 设置报表源
        report = New ReportDocument()
        report.Load(GetReportPath(RPT_NAME))

        ' 设置参数
        crvOrders.ParameterFieldInfo = GetParameterInfo(CType(Session("list"), ListItemCollection))

        crvOrders.ReportSource = report

        ' 显示报表
        crvOrders.DataBind()

    End Sub
   
    '----------------------------------------------------------------
    ' Function GetParameterInfo:
    '   从复选框列表获取参数字段信息
    ' Returns:
    '   参数字段
    ' Parameters:
    '   [in]  list: 复选框列表
    ' Throws:
    '  
    ' PreConditions:
    '  
    '----------------------------------------------------------------
    Private Function GetParameterInfo(ByVal list As ListItemCollection) As ParameterFields

        Dim item As ListItem
        Dim isEmpty As Boolean = True
        Dim itemCount As Integer = 0

        ' 声明将参数传递给查看器控件所需的变量。
        Dim paramFields As New ParameterFields()
        Dim paramField As New ParameterField()
        Dim discreteVal As New ParameterDiscreteValue()

        ' 参数是具有多个值的离散参数。

        ' 设置参数字段的名称，它必须和报表中的参数相符。
        paramField.ParameterFieldName = PARAMETER_FIELD_NAME

        For Each item In list
            If item.Selected Then
                isEmpty = False
                itemCount += 1

                ' 设置一个离散值并将其传递给该参数
                discreteVal.Value = item.Value
                paramField.CurrentValues.Add(discreteVal)
                ' 新建一个离散值
                discreteVal = New ParameterDiscreteValue()
            End If
        Next

        If isEmpty Then
            For Each item In list
                ' 设置一个离散值并将其传递给该参数
                discreteVal.Value = item.Value
                paramField.CurrentValues.Add(discreteVal)
                ' 新建一个离散值
                discreteVal = New ParameterDiscreteValue()
            Next
        End If

        ' 将该参数添加到参数字段集合。
        paramFields.Add(paramField)
        GetParameterInfo = paramFields

    End Function

本文地址：http://com.8s8s.com/it/it45304.htm