TdxChartCustomSeries.DataBinding Property
Provides access to data binding settings.
#Declaration
property DataBinding: TdxChartSeriesCustomDataBinding read; write;
#Property Value
Type | Description |
---|---|
Tdx |
Stores data binding settings that correspond to the active data access mode. Cast the property value to the corresponding terminal [Tdx 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:Data Binding [1] ValueType Data Binding [2] ValueClass Description 'Unbound'
Tdx Chart XYSeries Unbound Data Binding An XY chart series is not bound to a dataset. You need to populate series with data points manually. 'DB'
Tdx Chart XYSeries DBData Binding 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:Data Binding [1] ValueType Data Binding [2] ValueClass Description Unbound
Tdx Chart Simple Series Unbound Data Binding A simple series is not bound to a dataset. You need to populate series with data points manually. 'DB'
Tdx Chart Simple Series DBData Binding 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;
#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;
-
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.