如何在页面/RDL报表运行时修改数据

如何修改报表数据源（连接字符串或SQL查询）取决于您使用的报表类型。本文主要讲解了如何修改RDL报表数据源。

页面/RDL报表

运行时在页面或RDL报表中新建一个数据源，即在代码中设置，但通常最好在设计时设置数据源，然后在运行时用代码修改他们。设计时设置数据，您可以拖动字段放入报表填充你的字段列表，这样就可以避免很多手工绑定。

下面的代码修改设计时数据源和数据集的连接字符串和SQL查询..

// C#
private void Form1_Load(…)
{
// Instantiate the report.
GrapeCity.ActiveReports.PageReport rpt = new GrapeCity.ActiveReports.PageReport();
// Load a report definition file. 
rpt.Load(new System.IO.FileInfo(“PageReport1.rdlx”));
// Modify the connection string.
rpt.Report.DataSources[0].ConnectionProperties.DataProvider = “OLEDB”;
rpt.Report.DataSources[0].ConnectionProperties.ConnectString =
@”Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:/Reels.mdb”; 
// Define the SQL string to use.
String tmpQuery = “Select Top 10 * From Movie”;
// Modify the SQL string.
rpt.Report.DataSets[0].Query.CommandText = 
GrapeCity.ActiveReports.Expressions.ExpressionInfo.Parse(tmpQuery, 
GrapeCity.ActiveReports.Expressions.ExpressionResultType.String);
GrapeCity.ActiveReports.Document.PageDocument pageDocument = 
new GrapeCity.ActiveReports.Document.PageDocument(rpt);
viewer1.LoadDocument(pageDocument);
}

‘ VB.NET
Private Sub Form1_Load(…) Handles MyBase.Load
’ Instantiate the report.
Dim rpt As New GrapeCity.ActiveReports.PageReport()
’ Load a report definition file.
rpt.Load(New System.IO.FileInfo(“PageReport1.rdlx”))
’ Modify the connection string.
rpt.Report.DataSources(0).ConnectionProperties.DataProvider = “OLEDB”
rpt.Report.DataSources(0).ConnectionProperties.ConnectString _
= “Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:/Reels.mdb”
’ Define the SQL string to use.
Dim tmpQuery As [String] = “Select Top 10 * From Movie”
’ Modify the SQL string.
rpt.Report.DataSets(0).Query.CommandText = _ 
GrapeCity.ActiveReports.Expressions.ExpressionInfo.Parse(tmpQuery, _ 
GrapeCity.ActiveReports.Expressions.ExpressionResultType.[String])
Dim pageDocument As New GrapeCity.ActiveReports.Document.PageDocument(rpt)
Viewer1.LoadDocument(pageDocument)
End Sub