Object Data Source

• Dec 04, 2020
• 3 minutes to read

This tutorial shows how to add the DashboardObjectDataSource to data source storage and make it available to users.

1. In your application, create the SalesPersonData class and add the following code:

   public class SalesPersonData {
   
       public string SalesPerson { get; set; }
       public int Quantity { get; set; }
   
       public static List<SalesPersonData> CreateData() {
           List<SalesPersonData> data = new List<SalesPersonData>();
           string[] salesPersons = { "Andrew Fuller", "Michael Suyama",
                                   "Robert King", "Nancy Davolio",
                                   "Margaret Peacock", "Laura Callahan",
                                   "Steven Buchanan", "Janet Leverling" };
           var rnd = new Random();
           for (int i = 0; i < 100; i++) {
               SalesPersonData record = new SalesPersonData();
               record.SalesPerson = salesPersons[rnd.Next(0, salesPersons.Length)];
               record.Quantity = rnd.Next(0, 100);
               data.Add(record);
           }
           return data;
       }
   }
   

2. In the Default.aspx.cs (or .vb) file, create a public method that returns the configured dashboard’s data source storage (DataSourceInMemoryStorage) and define the Object data source.

   C#

   using System;
   using DevExpress.DashboardCommon;
   using DevExpress.DashboardWeb;
   
   public DataSourceInMemoryStorage CreateDataSourceStorage() {
       DataSourceInMemoryStorage dataSourceStorage = new DataSourceInMemoryStorage();
   
       // Registers an Object data source.            
       DashboardObjectDataSource objDataSource = new DashboardObjectDataSource("Object Data Source");
       dataSourceStorage.RegisterDataSource("objectDataSource", objDataSource.SaveToXml());  
   
       return dataSourceStorage;
   }
   

   VB.NET

   Imports System
   Imports DevExpress.DashboardCommon  
   Imports DevExpress.DashboardWeb
   
   Public Function CreateDataSourceStorage() As DataSourceInMemoryStorage
       Dim dataSourceStorage As New DataSourceInMemoryStorage()
   
       ' Registers an Object data source.
       Dim objDataSource As New DashboardObjectDataSource("Object Data Source")        
       dataSourceStorage.RegisterDataSource("objectDataSource", objDataSource.SaveToXml())
   
       Return dataSourceStorage
   End Function
   

3. Use the ASPxDashboard.DataLoading event to supply the dashboard with actual data at runtime.

   C#

   using DevExpress.DashboardWeb;
   using DevExpress.DataAccess.ObjectBinding;
   
   protected void Page_Load(object sender, EventArgs e) {
       // ...  
   
       ASPxDashboard1.DataLoading += DataLoading;
   }
   
   private void DataLoading(object sender, DataLoadingWebEventArgs e) {
       if(e.DataSourceName == "Object Data Source") {
           e.Data = SalesPersonData.CreateData();
       }
   }
   

   VB.NET

   Imports DevExpress.DashboardWeb
   Imports DevExpress.DataAccess.ObjectBinding
   
   Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
       ' ...  
   
       AddHandler ASPxDashboard1.DataLoading, AddressOf DataLoading
   End Sub
   
   Private Sub DataLoading(ByVal sender As Object, ByVal e As DataLoadingWebEventArgs)
       If e.DataSourceName = "Object Data Source" Then
           e.Data = SalesPersonData.CreateData()
       End If
   End Sub
   

4. Call the ASPxDashboard.SetDataSourceStorage method to configure the data source storage. Use the created CreateDataSourceStorage method as the SetDataSourceStorage parameter.

   C#

   using DevExpress.DashboardWeb;
   
   protected void Page_Load(object sender, EventArgs e) {
       // ...  
   
       // Configures the data source storage.
       ASPxDashboard1.SetDataSourceStorage(CreateDataSourceStorage());
   }
   

   VB.NET

   Imports DevExpress.DashboardWeb
   
   Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
       ' ...          
   
       '  Configures the data source storage.
       ASPxDashboard1.SetDataSourceStorage(CreateDataSourceStorage())
   End Sub
   

The Object Data Source is now available in the Web Dashboard:

Users can now bind dashboard items to data in the Web Dashboard’s UI.

Example

The example shows how to make a set of data sources available for users in the Web Dashboard application.

View Example: How to Register Data Sources for ASP.NET Web Forms Dashboard Control