TdxChartXYSeriesDBDataBinding Class

Stores data binding settings for an XY series in bound data access mode.

Declaration

TdxChartXYSeriesDBDataBinding = class(
    TdxChartSeriesDBDataBinding
)

Remarks

An XY series is in bound mode when its DataBindingType property is set to 'DB'. In this mode, you can use the DataSource property to bind the series to data. The ArgumentField and ValueField properties specify source fields in the underlying dataset for arguments and values, respectively.

The DataBinding property of an XY series references the TdxChartXYSeriesDBDataBinding class as a TdxChartSeriesCustomDataBinding object if the DataBindingType property of the series is set to 'DB'.

Note

You need to cast the DataBinding property value to the TdxChartXYSeriesDBDataBinding class to access the DataSource, ArgumentField, and ValueField properties.

Code Example: Create Three Bound Line Series

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

Delphi

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;

C++

  TdxChartXYDiagram *AXYDiagram;
  TdxChartXYSeries *AXYSeriesEurope, *AXSeriesAmericas, *AXYSeriesAfrica;
  TdxChartXYSeriesLineView *ALineView;
  TdxChartXYSeriesDBDataBinding *ADataBinding;
  // ...
  dxChartControl1->BeginUpdate();  // Initiates the following batch change
  try
  {
    dxChartControl1->Titles->Add()->Text = "Historic, Current, and Future Population Projection";
    AXYDiagram = new TdxChartXYDiagram(dxChartControl1->Owner);
    AXYDiagram->SetParentComponent(dxChartControl1);
    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 = __classid(TdxChartXYSeriesDBDataBinding);
    ADataBinding = dynamic_cast<TdxChartXYSeriesDBDataBinding*>(AXYSeriesEurope->DataBinding);
    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 = __classid(TdxChartXYSeriesLineView);  // Selects the Line series View
    ALineView := dynamic_cast<TdxChartXYSeriesLineView*>(AXYSeriesEurope->View);
    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
    ADataBinding = dynamic_cast<TdxChartXYSeriesDBDataBinding*>(AXYSeriesAmericas->DataBinding);
    ADataBinding->ValueField->FieldName = "Americas"; // Specifies a different source dataset field for values
    AXYSeriesAmericas->Caption = "Americas";  // Defines a different series caption
    AXYSeriesAfrica = AXYDiagram->AddSeries();  // Creates a new series with the default settings
    AXYSeriesAfrica->AssignFrom(AXYSeriesEurope);  // Copies all settings from the "Europe" series
    ADataBinding = dynamic_cast<TdxChartXYSeriesDBDataBinding*>(AXYSeriesAfrica->DataBinding);
    ADataBinding->ValueField->FieldName = "Africa";  // Specifies a different source dataset field for values
    AXYSeriesAfrica->Caption = "Africa";  // Defines a different series caption
  }
  __finally
  {
    dxChartControl1->EndUpdate(); // Calls EndUpdate regardless of the batch operation's success
  }
  // ...

Inheritance

TObject

TPersistent

TcxOwnedPersistent

TdxChartSeriesCustomDataBinding

TdxChartSeriesDBDataBinding

TdxChartXYSeriesDBDataBinding