Skip to main content

DevExpress v24.2 Update — Your Feedback Matters

Our What's New in v24.2 webpage includes product-specific surveys. Your response to our survey questions will help us measure product satisfaction for features released in this major update and help us refine our plans for our next major release.

Take the survey Not interested

TdxChartCustomSeries.DataBinding Property

Provides access to data binding settings.

#Declaration

Delphi
property DataBinding: TdxChartSeriesCustomDataBinding read; write;

#Property Value

Type Description
TdxChartSeriesCustomDataBinding

Stores data binding settings that correspond to the active data access mode.

Cast the property value to the corresponding terminal [TdxChartSeriesCustomDataBinding] descendant to access all public API members. You can call the DataBinding.ClassType function to identify the actual data binding settings type or use the DataBindingClass or DataBindingType property.

Refer to the Remarks section for the full list of available setting classes.

#Remarks

Use the DataBindingType or DataBindingClass property to switch between available data access modes.

#Available Data Binding Classes

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
'Unbound' TdxChartXYSeriesUnboundDataBinding An XY chart series is not bound to a dataset. You need to populate series with data points manually.
'DB' TdxChartXYSeriesDBDataBinding An XY chart series connects to a dataset and loads all data records into memory.
TdxChartSimpleSeries

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

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

#Code Example: Create Three Line Series in Bound Mode

The following code example creates three line series with identical appearance settings in bound mode:

var
  AXYDiagram: TdxChartXYDiagram;
  AXYSeriesAmericas, AXYSeriesEurope, AXYSeriesAfrica: TdxChartXYSeries;
  ALineView: TdxChartXYSeriesLineView;
  ADataBinding: TdxChartXYSeriesDBDataBinding;
begin
  dxChartControl1.BeginUpdate;  // Initiates the following batch change
  try
    dxChartControl1.Titles.Add.Text := 'Historic, Current, and Future Population Projection';
    AXYDiagram := dxChartControl1.AddDiagram<TdxChartXYDiagram>;
    AXYDiagram.Axes.AxisY.Title.Text := 'Population mid-year, millions';
    AXYDiagram.Axes.AxisX.Interlaced := True;
    AXYSeriesEurope := AXYDiagram.AddSeries('Europe');  // Creates a new series with the caption "Europe"
    AXYSeriesEurope.ShowInLegend := TdxChartSeriesShowInLegend.Diagram;
    AXYSeriesEurope.DataBindingClass := TdxChartXYSeriesDBDataBinding;
    ADataBinding := AXYSeriesEurope.DataBinding as TdxChartXYSeriesDBDataBinding;
    ADataBinding.DataSource := dsPopulation;  // Assigns a data source
    ADataBinding.DataSource.DataSet := mdPopulation;  // Assigns a dataset
    ADataBinding.DataSource.DataSet.Active := True;  // Enables the assigned dataset
    ADataBinding.ArgumentField.FieldName := 'Year';  // Specifies the source dataset field for arguments
    ADataBinding.ValueField.FieldName := 'Europe';  // Specifies the source dataset field for values
    AXYSeriesEurope.ViewClass := TdxChartXYSeriesLineView;  // Selects the Line series View
    ALineView := AXYSeriesEurope.View as TdxChartXYSeriesLineView;
    ALineView.Markers.Visible := True;  // Displays value markers
    ALineView.ValueLabels.Visible := True;  // Displays value labels
    ALineView.Appearance.StrokeOptions.Width := 2;  // Increases line width
    AXYSeriesAmericas := AXYDiagram.AddSeries;  // Creates a new series with the default settings
    AXYSeriesAmericas.AssignFrom(AXYSeriesEurope);  // Copies all settings from the "Europe" series
    AXYSeriesAmericas.Caption := 'Americas';  // Defines a different series caption
    // Specifies a different source dataset field for values
    ADataBinding := AXYSeriesAmericas.DataBinding as TdxChartXYSeriesDBDataBinding;
    ADataBinding.ValueField.FieldName := 'Americas';
    AXYSeriesAfrica := AXYDiagram.AddSeries;  // Creates a new series with the default settings
    AXYSeriesAfrica.AssignFrom(AXYSeriesEurope);  // Copies all settings from the "Europe" series
    AXYSeriesAfrica.Caption := 'Africa';  // Defines a different series caption
    // Specifies a different source dataset field for values
    ADataBinding := AXYSeriesAfrica.DataBinding as TdxChartXYSeriesDBDataBinding;
    ADataBinding.ValueField.FieldName := 'Africa';
  finally
    dxChartControl1.EndUpdate;  // Calls EndUpdate regardless of the batch operation's success
  end;
end;

VCL Chart Control: An XY Diagram Example with Three Line Series

#Code Example: Create Three Stacked Bar Series in Unbound Mode

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

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;

VCL Chart Control: An XY Diagram Example with Three Stacked Bar Series

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.

See Also