ICustomPropertyHistoryAttribute<T>.GetHistoryMessage(T, T, String) Method

Returns the message displayed in the Dashboard Designer’s history when a user changes a custom property value.

Namespace: DevExpress.DashboardCommon

Assembly: DevExpress.Dashboard.v24.2.Core.dll

Declaration

C#

string GetHistoryMessage(
    T newValue,
    T oldValue,
    string dashboardItemName
)

VB.NET

Function GetHistoryMessage(
    newValue As T,
    oldValue As T,
    dashboardItemName As String
) As String

Parameters

Name	Type	Description
newValue	T	A new custom property’s value.
oldValue	T	A previous custom property’s value.
dashboardItemName	String	A custom dashboard item’s component name.

Returns

Type	Description
String	The message displayed in the Dashboard Designer’s history

Remarks

The following code snippet specifies the history message for the ShowLegend custom property:

FunnelItemMetadata.cs

using DevExpress.DashboardCommon;
using System.ComponentModel;

namespace TutorialsCustomItems {
    public class FunnelItemMetadata : CustomItemMetadata {
        // ...
        [ShowLegendCustom]
        public bool ShowLegend {
            get { return GetCustomPropertyValue<bool>(); }
            set { SetCustomPropertyValue(value); }
        }
        public class ShowLegendCustomAttribute : Attribute, ICustomPropertyValueConverterAttribute<bool>, ICustomPropertyHistoryAttribute<bool>{
            // ...
            public string GetHistoryMessage(bool newValue, bool oldValue, string dashboardItemName){
                return (newValue ? "Enable" : "Disable") + " Legend for the " + dashboardItemName;
            }
        }
    }
}

FunnelItemMetadata.vb

Imports DevExpress.DashboardCommon
Imports System.ComponentModel

Namespace TutorialsCustomItems
    Public Class FunnelItemMetadata
        Inherits CustomItemMetadata
        ' ...
      <ShowLegendCustom>
      Public Property ShowLegend() As Boolean
        Get
          Return GetCustomPropertyValue(Of Boolean)()
        End Get
        Set(ByVal value As Boolean)
          SetCustomPropertyValue(value)
        End Set
      End Property
         Public Class ShowLegendCustomAttribute
     Inherits Attribute
     Implements ICustomPropertyValueConverterAttribute(Of Boolean), ICustomPropertyHistoryAttribute(Of Boolean)
            ' ...
            Public Function GetHistoryMessage(ByVal newValue As Boolean, ByVal oldValue As Boolean, ByVal dashboardItemName As String) As String
                Return "Legend " & (If(newValue, "enabled", "disabled")) & " " & dashboardItemName
            End Function
        End Class
    End Class
End Namespace