TdxChartSeriesCustomDataBinding Class
The base class for all data binding setting classes used by chart series.
Declaration
TdxChartSeriesCustomDataBinding = class(
TcxOwnedPersistent
)
Remarks
The TdxChartSeriesCustomDataBinding
class implements data binding settings common to all data access modes available in the Chart control.
Main API Members
The list below outlines key members of the TdxChartSeriesCustomDataBinding
class that allow you to configure data binding settings.
- Refresh
- Repopulates series point data from the underlying dataset.
- Series
- Provides access to the series to which the current data binding settings belong.
- Assign
- Copy data binding settings between series.
Terminal TdxChartSeriesCustomDataBinding Class Descendants
The DataBinding property of a series references a TdxChartSeriesCustomDataBinding
object. Cast it to the selected series data binding class to access all data binding type-specific properties and methods. Refer to the following tables for information on the target data binding class depending on the used TdxChartCustomSeries class descendant and the DataBindingType property value:
- TdxChartXYSeries
An XY series uses the following data binding classes depending on the
DataBindingType
property value:DataBindingType[1] Value DataBindingClass[2] Value Description 'DB'
[3]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'
[3]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.
Code Example: 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;
Code Example: 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;
Inheritance
-
The DataBindingType property setter updates the DataBindingClass and DataBinding property values according to the selected data access mode.
-
The DataBindingClass property setter updates the DataBindingType and DataBinding property values according to the selected data access mode.
-
The default data access mode.