TdxChartCustomSeries.DataBindingType Property

Specifies the active data access mode.

Declaration

property DataBindingType: string read; write;

Property Value

Type	Description
string	The name of the active data access mode. Refer to the Remarks section for details.

Remarks

Use the DataBindingType or DataBindingClass property to switch between available data access modes. Different TdxChartCustomSeries class descendants use different data binding setting classes:

TdxChartXYSeries

An XY series uses the following data binding classes depending on the DataBindingType property value:

DataBindingType[1] Value	DataBindingClass[2] Value	Description
'DB'	TdxChartXYSeriesDBDataBinding	An XY chart series connects to a dataset and loads all data records into memory.
'Unbound'	TdxChartXYSeriesUnboundDataBinding	An XY chart series is not bound to a dataset. You need to populate series with data points manually.

TdxChartSimpleSeries

A simple series uses the following data binding classes depending on the DataBindingType property value:

DataBindingType[1] Value	DataBindingClass[2] Value	Description
'DB'	TdxChartSimpleSeriesDBDataBinding	A simple series connects to a dataset and loads all data records into memory.
Unbound	TdxChartSimpleSeriesUnboundDataBinding	A simple series is not bound to a dataset. You need to populate series with data points manually.

Example

The following code example creates three stacked bar series with identical appearance settings in unbound data access mode:

Delphi

uses cxDataStorage;  // This unit declares the TcxStringValueType class
// ...
var
  AXYDiagram: TdxChartXYDiagram;
  AXY2018Series, AXY2019Series, AXY2020Series: TdxChartXYSeries;
  AStackedBarView: TdxChartXYSeriesStackedBarView;
  ADataBinding: TdxChartXYSeriesUnboundDataBinding;
begin
  dxChartControl1.BeginUpdate;  // Initiates the following batch change
  try
    AXYDiagram := dxChartControl1.AddDiagram<TdxChartXYDiagram>('DevAV Sales By Region');
    AXYDiagram.Title.Appearance.FontOptions.Size := 20;
    AXYDiagram.Axes.AxisY.Title.Text := 'Millions of Dollars';
    AXYDiagram.Axes.AxisY.Title.Appearance.FontOptions.Size := 14;
    AXY2018Series := AXYDiagram.AddSeries('2018');  // Creates a new series with the caption "2018"
    // Selects the unbound data access mode
    AXY2018Series.DataBindingClass := TdxChartXYSeriesUnboundDataBinding;
    ADataBinding := AXY2018Series.DataBinding as TdxChartXYSeriesUnboundDataBinding;
    // Selects the string data type for arguments
    ADataBinding.ArgumentField.ValueTypeClass := TcxStringValueType;
    AXY2018Series.ViewClass := TdxChartXYSeriesStackedBarView;  // Selects the Stacked Bar series View
    AStackedBarView := AXY2018Series.View as TdxChartXYSeriesStackedBarView;
    AStackedBarView.ValueLabels.Visible := True;  // Displays value labels on bars
    AStackedBarView.ValueLabels.TextFormat := '{V:0.000}';  // Changes the number display format
    AStackedBarView.ValueLabels.Appearance.FontOptions.Bold := True;
    AXY2018Series.Points.Add('Asia', 4.2372);
    AXY2018Series.Points.Add('Australia', 1.7871);
    AXY2018Series.Points.Add('Europe', 3.0884);
    AXY2018Series.Points.Add('North America', 3.4855);
    AXY2018Series.Points.Add('South America', 1.6027);
    AXY2019Series := AXYDiagram.AddSeries;  // Creates a new series with the default settings
    AXY2019Series.AssignFrom(AXY2018Series);  // Copies all settings from the "2018" series
    AXY2019Series.Caption := '2019';  // Defines a different series caption
    AXY2019Series.Points.Add('Asia', 4.7685);
    AXY2019Series.Points.Add('Australia', 1.9576);
    AXY2019Series.Points.Add('Europe', 3.3579);
    AXY2019Series.Points.Add('North America', 3.7477);
    AXY2019Series.Points.Add('South America', 1.8237);
    AXY2020Series := AXYDiagram.AddSeries('2020');  // Creates a new series with the default settings
    AXY2020Series.AssignFrom(AXY2018Series);  // Copies all settings from the "2018" series
    AXY2020Series.Caption := '2020';  // Defines a different series caption
    AXY2020Series.Points.Add('Asia', 5.289);
    AXY2020Series.Points.Add('Australia', 2.2727);
    AXY2020Series.Points.Add('Europe', 3.7257);
    AXY2020Series.Points.Add('North America', 4.1825);
    AXY2020Series.Points.Add('South America', 2.1172);
  finally
    dxChartControl1.EndUpdate;  // Calls EndUpdate regardless of the batch operation's success
  end;
end;

C++

#include "cxDataStorage.hpp"  // This header declares the TcxStringValueType class
// ...
  TdxChartXYDiagram *AXYDiagram;
  TdxChartXYSeries *AXY2018Series, *AXY2019Series, *AXY2020Series;
  TdxChartXYSeriesStackedBarView *AStackedBarView;
  TdxChartXYSeriesUnboundDataBinding *ADataBinding;
  // ...
  dxChartControl1->BeginUpdate();  // Initiates the following batch change
  try
  {
    AXYDiagram = new TdxChartXYDiagram(dxChartControl1->Owner);
    AXYDiagram->SetParentComponent(dxChartControl1);
    AXYDiagram->Title->Text = "DevAV Sales by Region";
    AXYDiagram->Title->Appearance->FontOptions->Size = 20;
    AXYDiagram->Axes->AxisY->Title->Text = "Millions of Dollars";
    AXYDiagram->Axes->AxisY->Title->Appearance->FontOptions->Size = 14;
    AXYSeries = AXYDiagram->AddSeries("2018"); // Creates a new series with the caption "2018"
    // Selects the unbound data access mode
    AXYSeries->DataBindingClass = __classid(TdxChartXYSeriesUnboundDataBinding);
    ADataBinding = dynamic_cast<TdxChartXYSeriesUnboundDataBinding*>(AXY2018Series->DataBinding);
    // Selects the string data type for arguments
    ADataBinding->ArgumentField->ValueTypeClass = __classid(TcxStringValueType);
    // Selects the Stacked Bar series View
    AXYSeries->ViewClass = __classid(TdxChartXYSeriesStackedBarView);
    AStackedBarView = dynamic_cast<TdxChartXYSeriesStackedBarView*>(AXY2018Series->View);
    AStackedBarView->ValueLabels->Visible = true; // Displays value labels on bars
    AStackedBarView->ValueLabels->TextFormat = "{V:0.000}"; // Changes the number display format
    AStackedBarView->ValueLabels->Appearance->FontOptions->Bold = true;
    AXY2018Series->Points->Add("Asia", 4.2372);
    AXY2018Series->Points->Add("Australia", 1.7871);
    AXY2018Series->Points->Add("Europe", 3.0884);
    AXY2018Series->Points->Add("North America", 3.4855);
    AXY2018Series->Points->Add("South America", 1.6027);
    AXY2019Series = AXYDiagram->AddSeries();  // Creates a new series with the default settings
    AXY2019Series->AssignFrom(AXY2018Series); // Copies all settings from the "2018" series
    AXY2019Series->Caption = "2019"; // Defines a different series caption
    AXY2019Series->Points->Add("Asia", 4.7685);
    AXY2019Series->Points->Add("Australia", 1.9576);
    AXY2019Series->Points->Add("Europe", 3.3579);
    AXY2019Series->Points->Add("North America", 3.7477);
    AXY2019Series->Points->Add("South America", 1.8237);
    AXY2020Series = AXYDiagram->AddSeries();  // Creates a new series with the default settings
    AXY2020Series->AssignFrom(XY2018Series); // Copies all settings from the "2018" series
    AXY2020Series->Caption = "2020";  // Defines a different series caption
    AXY2020Series->Points->Add("Asia", 5.289);
    AXY2020Series->Points->Add("Australia", 2.2727);
    AXY2020Series->Points->Add("Europe", 3.7257);
    AXY2020Series->Points->Add("North America", 4.1825);
    AXY2020Series->Points->Add("South America", 2.1172);
  }
  __finally
  {
    dxChartControl1->EndUpdate(); // Calls EndUpdate regardless of the batch operation's success
  }
  // ...

The DataBindingType property’s default value is 'DB'.

Footnotes

1. The DataBindingType property setter updates the DataBindingClass and DataBinding property values according to the selected data access mode.

2. The DataBindingClass property setter updates the DataBindingType and DataBinding property values according to the selected data access mode.