Chart data is requested via a Market object using one of the
BeginRequestChartData methods. Chart data is retrieved asynchronously, so these methods will always return immediately. When calling BeginRequestChartData, you will supply a callback method that will be called when the chart data is ready.
The BeginRequestChartData method returns an
IChartDataRequest object. You can obtain the unique chart data request ID via the RequestID property of this object.
Example chart data request:
Private Sub RequestChartData()
Dim dtEnddate As DateTime = DateTime.Now
Dim dtStartDate As DateTime = dtEndDate.AddDays(-60)
Dim enBarType As T4.ChartDataType = ChartDataType.Day
' Request bar data.
Dim oReq As T4.API.IChartDataRequest = Me.moMarket.BeginRequestChartData( dtStartDate, dtEnddate, enBarType, AddressOf IChartDataRequest_ChartDataComplete)
Trace.WriteLine(String.Format("RequestChartData(), Start Date: {0:MM/dd/yyyy}, End Date: {1:MM/dd/yyyy}, RequestID: {2}", dtStartDate, dtEnddate, oReq.RequestID))
End Sub
Private Sub IChartDataRequest_ChartDataComplete(ByVal poRequest As T4.API.IChartDataRequest)
' Process the bar data.
End Sub
Once the chart data retrieval has completed, the callback supplied on the request method will be called. The IChartDataRequest object returned as a result of calling BeginRequestChartData is the sole argument supplied to the callback. This object will contain all of the details of the original request, and the chart data.
Note: There is no need to lock to lock the Market object when making chart data requests nor when processing the chart data returned in the IChartDataRequest object.
Note: If you make multiple requests for data on the same or different markets then you may not receive the responses in the same order that you requested the data.