public DashboardState CreateDashboardState()
{
    DashboardState state = new DashboardState();
    // Set a range for a Range Filter.
    state.Items.Add(new DashboardItemState("rangeFilterDashboardItem1")
    {
        RangeFilterState = new RangeFilterState(
            new RangeFilterSelection(
                new DateTime(2015, 1, 1), new DateTime(2017, 1, 1)))
    });
    // Specify master filter and drill-down values.
    state.Items.Add(new DashboardItemState("gridDashboardItem1")
    {
        MasterFilterValues = new List<object[]>() { 
            new object[] { "Gravad lax" }, 
            new object[] { "Ikura" } },
        DrillDownValues = new List<object>() { "Seafood" }
    });
    // Set a dashboard item layer.
    state.Items.Add(new DashboardItemState("treemapDashboardItem1")
    {
        SelectedLayerIndex = 1
    });
    // Specify a default tab page.
    state.Items.Add(new DashboardItemState("tabContainerDashboardItem1")
    {
        TabPageName = "dashboardTabPage2"
    });
    // Define a dashboard parameter value.
    state.Parameters.Add(new DashboardParameterState()
    {
        Name = "ParameterCountry",
        Value = "UK",
        Type = typeof(string)
    });
    return state;
}

Public Function CreateDashboardState() As DashboardState
    Dim state As New DashboardState()
    ' Set a range for a Range Filter.
    state.Items.Add(New DashboardItemState("rangeFilterDashboardItem1") With {
                    .RangeFilterState = New RangeFilterState(
                    New RangeFilterSelection(New Date(2015, 1, 1), New Date(2017, 1, 1))
                    )})
    ' Specify master filter and drill-down values.
    state.Items.Add(New DashboardItemState("gridDashboardItem1") With {
        .MasterFilterValues = New List(Of Object())() From {
            New Object() { "Gravad lax" },
            New Object() { "Ikura" }
        },
        .DrillDownValues = New List(Of Object)() From {"Seafood"}
    })
    ' Set a dashboard item layer.
    state.Items.Add(New DashboardItemState("treemapDashboardItem1") With {.SelectedLayerIndex = 1})
    ' Specify a default tab page.
    state.Items.Add(New DashboardItemState("tabContainerDashboardItem1") With {.TabPageName = "dashboardTabPage2"})
    ' Define a dashboard parameter value.
    state.Parameters.Add(New DashboardParameterState() With {.Name = "ParameterCountry", .Value = "UK", .Type = GetType(String)})
    Return state
End Function

using DevExpress.DashboardCommon;
using DevExpress.DashboardWin;
// ...
DashboardState state = new DashboardState();
const string path = @"..\..\Dashboards\dashboard1.xml";
// ... 
private void DashboardViewer_DashboardStateChanged(object sender, DashboardStateChangedEventArgs e) {
  state = dashboardViewer.GetDashboardState();
  var stateValue = state.SaveToXml().ToString(SaveOptions.DisableFormatting);
  dashboardViewer.Dashboard.CustomProperties.SetValue("DashboardState", stateValue);          
}

private void DashboardViewer_SetInitialDashboardState(object sender, SetInitialDashboardStateEventArgs e) {
  e.InitialState = state;
}
// ...

Imports DevExpress.DashboardCommon
Imports DevExpress.DashboardWin
' ...
Private state As New DashboardState()
Private Const path As String = "..\..\Dashboards\dashboard1.xml"
' ...
Private Sub DashboardViewer_DashboardStateChanged(ByVal sender As Object, ByVal e As DashboardStateChangedEventArgs)
  state = dashboardViewer.GetDashboardState()
  Dim stateValue = state.SaveToXml().ToString(SaveOptions.DisableFormatting)
  dashboardViewer.Dashboard.CustomProperties.SetValue("DashboardState", stateValue)
End Sub

Private Sub DashboardViewer_SetInitialDashboardState(ByVal sender As Object, ByVal e As SetInitialDashboardStateEventArgs)
  e.InitialState = state
End Sub
' ...

using DevExpress.DashboardCommon;
using DevExpress.DashboardWin;
using DevExpress.XtraEditors;
using System;
using System.Collections.Generic;

namespace WinFormsDashboard_DashboardState
{
    public partial class Form1 : XtraForm
    {
        public Form1() {
            dashboardViewer1.ConfigureDataConnection += DashboardViewer1_ConfigureDataConnection;
            dashboardViewer1.CustomizeDashboardTitle += DashboardViewer1_CustomizeDashboardTitle;
            dashboardViewer1.UseNeutralFilterMode = true;
        }

         public DashboardState CreateDashboardState(){
            DashboardState state = new DashboardState();
            //Clears selections in the LisxBox item.
            state.Items.Add(new DashboardItemState("listBoxDashboardItem1") {
                MasterFilterValues = new List<object[]>()
            });
            //The lines below clears all filter values if neutral filter mode is disabled:
            //state.Items.Add(new DashboardItemState("listBoxDashboardItem1") {
            // MasterFilterValues = null
            //});
            return state;
        }
        private void DashboardViewer1_CustomizeDashboardTitle(object sender, CustomizeDashboardTitleEventArgs e){
            DashboardToolbarItem resetStateItem = new DashboardToolbarItem("Reset State",
              new Action<DashboardToolbarItemClickEventArgs>((args) => {
                  dashboardViewer1.SetDashboardState(CreateDashboardState());
              }));
            resetStateItem.Caption = "Reset Dashboard State";
            e.Items.Add(resetStateItem);
        }
        //...
    }
}

Imports DevExpress.DashboardCommon
Imports DevExpress.DashboardWin
Imports DevExpress.XtraEditors
Imports System
Imports System.Collections.Generic

Namespace WinFormsDashboard_DashboardState
    Partial Public Class Form1
        Inherits XtraForm
        Public Sub New()
            dashboardViewer1.ConfigureDataConnection += DashboardViewer1_ConfigureDataConnection
            AddHandler dashboardViewer1.CustomizeDashboardTitle, AddressOf DashboardViewer1_CustomizeDashboardTitle
            dashboardViewer1.UseNeutralFilterMode = True
        End Sub

         Public Function CreateDashboardState() As DashboardState
            Dim state As New DashboardState()
            'Clears selections in the LisxBox item.
            state.Items.Add(New DashboardItemState("listBoxDashboardItem1") With {.MasterFilterValues = New List(Of Object())()})
            'The lines below clears all values if neutral filter mode is disabled:
            'state.Items.Add(new DashboardItemState("listBoxDashboardItem1") {
            ' MasterFilterValues = null
            '});
            Return state
         End Function
        Private Sub DashboardViewer1_CustomizeDashboardTitle(ByVal sender As Object, ByVal e As CustomizeDashboardTitleEventArgs)
            Dim resetStateItem As New DashboardToolbarItem("Reset State", New Action(Of DashboardToolbarItemClickEventArgs)(Function(args) AnonymousMethod1(args)))
            resetStateItem.Caption = "Reset Dashboard State"
            e.Items.Add(resetStateItem)
        End Sub

        Private Function AnonymousMethod1(ByVal args As Object) As Boolean
            dashboardViewer1.SetDashboardState(CreateDashboardState())
            Return True
        End Function
     '...
    End Class
End Namespace