XtraReport.ParametersRequestValueChanged Event

Occurs when the parameter values are changed in the Parameters UI.

Namespace: DevExpress.XtraReports.UI

Assembly: DevExpress.XtraReports.v18.2.dll

Declaration

C#

public event EventHandler<ParametersRequestValueChangedEventArgs> ParametersRequestValueChanged

VB.NET

Public Event ParametersRequestValueChanged As EventHandler(Of ParametersRequestValueChangedEventArgs)

Event Data

The ParametersRequestValueChanged event's data class is ParametersRequestValueChangedEventArgs. The following properties provide information specific to this event:

Property	Description
ChangedParameterInfo	Contains information about the parameter, which value was changed.
ParametersInformation	Provides access to information about the requested parameters. Inherited from ParametersRequestEventArgs.

Remarks

The ParametersRequestValueChanged event fires only for Windows Forms applications.

Example

This example demonstrates how to perform report parameter validation, and restore the previous parameter value if the validation fails (if the parameter value is greater than 10 or less than 0).

This is achieved by handling the report’s XtraReport.ParametersRequestSubmit and XtraReport.ParametersRequestValueChanged events.

XtraReport1.cs

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using DevExpress.XtraReports.UI;
using DevExpress.XtraReports.Parameters;
// ...

namespace CancelSubmitParameters {
    public partial class XtraReport1 : XtraReport {
        int parameter;
        public XtraReport1() {
            InitializeComponent();
        }

        private void XtraReport1_ParametersRequestSubmit(object sender, 
            ParametersRequestEventArgs e) {
            if ((int)e.ParametersInformation[0].Parameter.Value > 10 || 
                (int)e.ParametersInformation[0].Parameter.Value < 0) {
                e.ParametersInformation[0].Parameter.Value = parameter;
                e.ParametersInformation[0].Editor.Text = parameter.ToString();
            }
        }

        private void XtraReport1_ParametersRequestValueChanged(object sender, 
            ParametersRequestValueChangedEventArgs e) {
            parameter = (int)e.ChangedParameterInfo.Parameter.Value;
        }

    }
}

Form1.cs

using System;
using System.Windows.Forms;
using DevExpress.XtraReports.UI;
// ...

namespace CancelSubmitParameters {
    public partial class Form1 : Form {
        public Form1() {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e) {
            XtraReport1 report = new XtraReport1();
            ReportPrintTool printTool = new ReportPrintTool(report);
            printTool.ShowPreviewDialog();
        }

    }
}

XtraReport1.vb

Imports Microsoft.VisualBasic
Imports System
Imports System.Drawing
Imports System.Collections
Imports System.ComponentModel
Imports DevExpress.XtraReports.UI
Imports DevExpress.XtraReports.Parameters
' ...

Namespace CancelSubmitParameters
    Partial Public Class XtraReport1
        Inherits XtraReport
        Private parameter As Integer
        Public Sub New()
            InitializeComponent()
        End Sub

        Private Sub XtraReport1_ParametersRequestSubmit(ByVal sender As Object, _
            ByVal e As ParametersRequestEventArgs) Handles MyBase.ParametersRequestSubmit
            If CInt(Fix(e.ParametersInformation(0).Parameter.Value)) > 10 _
                OrElse CInt(Fix(e.ParametersInformation(0).Parameter.Value)) < 0 Then
                e.ParametersInformation(0).Parameter.Value = parameter
                e.ParametersInformation(0).Editor.Text = parameter.ToString()
            End If
        End Sub

        Private Sub XtraReport1_ParametersRequestValueChanged(ByVal sender As Object, _
            ByVal e As ParametersRequestValueChangedEventArgs) Handles MyBase.ParametersRequestValueChanged
            parameter = CInt(Fix(e.ChangedParameterInfo.Parameter.Value))
        End Sub

    End Class
End Namespace

Form1.vb

Imports Microsoft.VisualBasic
Imports System
Imports System.Windows.Forms
Imports DevExpress.XtraReports.UI
' ...

Namespace CancelSubmitParameters
    Partial Public Class Form1
        Inherits Form
        Public Sub New()
            InitializeComponent()
        End Sub

        Private Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles button1.Click
            Dim report As New XtraReport1()
            Dim printTool As New ReportPrintTool(report)
            printTool.ShowPreviewDialog()
        End Sub

    End Class
End Namespace