How to Get Dashboard Item Data Asynchronously

• Dec 11, 2019
• 2 minutes to read

This example demonstrates how to get the data displayed in the dashboard item asynchronously when the dashboard is loaded.

Note

The complete sample project How to Get Dashboard Item Data Asynchronously is available in the DevExpress Examples repository.

C#

using DevExpress.DashboardCommon;
using DevExpress.XtraEditors;
using System;
using System.Threading.Tasks;

namespace DataCounterExample
{
    public partial class ViewerForm1 : XtraForm {
        public ViewerForm1() {
            InitializeComponent();
            dashboardViewer1.Initialized += OnDashboardViewerInitialized;
            dashboardViewer1.MasterFilterSet += OnDashboardViewerMasterFilterSet;
            dashboardViewer1.MasterFilterCleared += OnDashboardViewerMasterFilterCleared;
        }

        async void OnDashboardViewerInitialized(object sender, EventArgs e) {
            simpleLabelItem1.Text = await GetLabelText("choroplethMapDashboardItem1", "Map");
            simpleLabelItem2.Text = await GetLabelText("gridDashboardItem1", "Grid");
        }

        async void OnDashboardViewerMasterFilterSet(object sender, MasterFilterSetEventArgs e) {
            simpleLabelItem2.Text = await GetLabelText("gridDashboardItem1", "Grid");
        }

        async void OnDashboardViewerMasterFilterCleared(object sender, MasterFilterClearedEventArgs e) {
            simpleLabelItem2.Text = await GetLabelText("gridDashboardItem1", "Grid");
        }

        async Task<string> GetLabelText(string itemName, string itemCaption) {
            var data = await dashboardViewer1.GetItemDataAsync(itemName);
            int count = data.GetAxisPoints(data.GetAxisNames()[0]).Count;
            return string.Format("{0}: {1}", itemCaption, count);
        }
    }
}

VB.NET

Imports DevExpress.DashboardCommon
Imports DevExpress.XtraEditors
Imports System
Imports System.Threading.Tasks

Namespace DataCounterExample
    Partial Public Class ViewerForm1
        Inherits XtraForm

        Public Sub New()
            InitializeComponent()
            AddHandler dashboardViewer1.Initialized, AddressOf OnDashboardViewerInitialized
            AddHandler dashboardViewer1.MasterFilterSet, AddressOf OnDashboardViewerMasterFilterSet
            AddHandler dashboardViewer1.MasterFilterCleared, AddressOf OnDashboardViewerMasterFilterCleared
        End Sub

        Private Async Sub OnDashboardViewerInitialized(ByVal sender As Object, ByVal e As EventArgs)
            simpleLabelItem1.Text = Await GetLabelText("choroplethMapDashboardItem1", "Map")
            simpleLabelItem2.Text = Await GetLabelText("gridDashboardItem1", "Grid")
        End Sub

        Private Async Sub OnDashboardViewerMasterFilterSet(ByVal sender As Object, ByVal e As MasterFilterSetEventArgs)
            simpleLabelItem2.Text = Await GetLabelText("gridDashboardItem1", "Grid")
        End Sub

        Private Async Sub OnDashboardViewerMasterFilterCleared(ByVal sender As Object, ByVal e As MasterFilterClearedEventArgs)
            simpleLabelItem2.Text = Await GetLabelText("gridDashboardItem1", "Grid")
        End Sub

        Private Async Function GetLabelText(ByVal itemName As String, ByVal itemCaption As String) As Task(Of String)
            Dim data = Await dashboardViewer1.GetItemDataAsync(itemName)
            Dim count As Integer = data.GetAxisPoints(data.GetAxisNames()(0)).Count
            Return String.Format("{0}: {1}", itemCaption, count)
        End Function
    End Class
End Namespace