项目在使用过程，需要使用到参数传递选择，以前对水晶报表久有耳闻，不过使用起来，还真的是麻烦，很多东西从来没有接触过，遇到的问题多西多啊！
以下是MSDN上关于解决参数传递的问题范例，先记录下，免的以后忘了！
Default.aspx
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<%@ Page Language="C#" AutoEventWireup="true" CodeFile="CustomersByCity.aspx.cs" Inherits="CustomersByCity" %>
<%@ Register Assembly="CrystalDecisions.Web, Version=10.2.3600.0, Culture=neutral, PublicKeyToken=692fbea5521e1304"
Namespace="CrystalDecisions.Web" TagPrefix="CR" %>
<!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 runat="server">
<title>无标题页</title>
<link href="/aspnet_client/System_Web/2_0_50727/CrystalReportWebFormViewer3/css/default.css"
rel="stylesheet" type="text/css" />
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:ListBox ID="defaultParameterValuesList" runat="server" SelectionMode="Multiple">
</asp:ListBox>
<asp:Button ID="redisplay" runat="server" OnClick="redisplay_Click" Text="Redisplay Report" />
<cr:crystalreportviewer id="CrystalReportViewer1" runat="server" autodatabind="True"
height="1123px" reportsourceid="CrystalReportSource1" reuseparametervaluesonrefresh="True"
width="897px"></cr:crystalreportviewer>
<cr:crystalreportsource id="CrystalReportSource1" runat="server">
<Report FileName="CustomersByCity.rpt"></Report>
</cr:crystalreportsource>
</div>
</form>
</body>
</html>
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Default.aspx.cs
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using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using CrystalDecisions.CrystalReports.Engine;
using CrystalDecisions.Shared;
public partial class CustomersByCity : System.Web.UI.Page
{
private const string PARAMETER_FIELD_NAME = "City";
protected void Page_Load(object sender, EventArgs e)
{
}
private void Page_Init(object sender, EventArgs e)
{
ConfigureCrystalReports();
}
private void ConfigureCrystalReports()
{
ArrayList arrayList = new ArrayList();
string reportPath = Server.MapPath("CustomersByCity.rpt");
CrystalReportViewer1.ReportSource = reportPath;
ParameterFields parameterFields = CrystalReportViewer1.ParameterFieldInfo;
if (!IsPostBack)
{
defaultParameterValuesList.DataSource = GetDefaultValuesFromParameterField(parameterFields);
defaultParameterValuesList.DataBind();
arrayList.Add("Paris");
arrayList.Add("Tokyo");
Session["arrayList"] = arrayList;
}
else
{
arrayList = (ArrayList)Session["arrayList"];
}
SetCurrentValuesForParameterField(parameterFields, arrayList);
}
private void SetCurrentValuesForParameterField(ParameterFields parameterFields, ArrayList arrayList)
{
ParameterValues currentParameterValues = new ParameterValues();
foreach (object submittedValue in arrayList)
{
ParameterDiscreteValue parameterDiscreteValue = new ParameterDiscreteValue();
parameterDiscreteValue.Value = submittedValue.ToString();
currentParameterValues.Add(parameterDiscreteValue);
}
ParameterField parameterField = parameterFields[PARAMETER_FIELD_NAME];
parameterField.CurrentValues = currentParameterValues;
}
private ArrayList GetDefaultValuesFromParameterField(ParameterFields parameterFields)
{
ParameterField parameterField = parameterFields[PARAMETER_FIELD_NAME];
ParameterValues defaultParameterValues = parameterField.DefaultValues;
ArrayList arrayList = new ArrayList();
foreach (ParameterValue parameterValue in defaultParameterValues)
{
if (!parameterValue.IsRange)
{
ParameterDiscreteValue parameterDiscreteValue = (ParameterDiscreteValue)parameterValue;
arrayList.Add(parameterDiscreteValue.Value.ToString());
}
}
return arrayList;
}
protected void redisplay_Click(object sender, EventArgs e)
{
ArrayList arrayList = new ArrayList();
foreach (ListItem item in defaultParameterValuesList.Items)
{
if (item.Selected)
{
arrayList.Add(item.Value);
}
}
Session["arrayList"] = arrayList;
ConfigureCrystalReports();
}
}
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其他详细说明请见MSDN:ms-help://MS.MSDNQTR.v80.chs/MS.MSDN.v80/MS.VisualStudio.v80.chs/crystlmn/html/crtsktutorialscrvparametersdiscrete.htm
