TdxChartCustomLabels.TextFormat Property

Specifies a formatting pattern for value labels.

Declaration

delphi

property TextFormat: TdxChartTextFormat read; write;

Property Value

Type	Description
TdxChartTextFormat

The formatting pattern for value labels.

Remarks

Use the TextFormat property to define a formatting pattern for labels. The formatting pattern can consist of static content and one or more placeholder fields. A placeholder field is an expression enclosed in curly brackets that starts with a supported placeholder variable followed by a colon and a value formatting expression.

Text Format Example

The following expression displays a series value with two decimal places followed by a measurement unit on every simple series value label: {V:0.00}M km².

Supported Placeholder Field Variables

{V}A series point value. If custom display text is defined for a series point value, the {V} placeholder variable displays this text instead of the actual value.{A}A series point argument. If custom display text is defined for a series point argument, the {A} placeholder variable displays this text instead of the actual value.{S}A series caption.{TV}A total value in a simple series. This placeholder variable is not supported in an XY series.

Supported Formatting Expressions

The Chart control supports all Spreadsheet-compatible formats as well as the following formatting expressions for date/time values:

c

A label displays a date followed by a time value. ShortDateFormat and LongTimeFormat field values define date and time formats, respectively.

Note

The time value is hidden if it matches midnight.

dddddA label displays only a date value. The ShortDateFormat field value defines the date format.ddddddA label displays only a date value. The LongDateFormat field value defines the date format.tA label displays only a time value. The ShortTimeFormat field value defines the time format.ttA label displays only a time value. The LongTimeFormat field value defines the time format.

Placeholder Field Errors

A label displays the following string if the formatting pattern contains an unsupported placeholder field: 'Variable "" not found!'.

Code Example: Apply Custom Formatting to Value Labels

The code example in this section displays and configures value labels for 2018 , 2019 , and 2020 simple Bar series.

How to Test this Code Example

Follow the steps below to test this code example in your RAD Studio IDE:

Copy the DFM code snippet demonstrated within the current section.
Create a new project in the IDE and focus an empty form.
Press Ctrl + V to populate the form with preconfigured components.
Create an empty OnCreate event for the form, paste the code example, and run the project.

object dxChartControl1: TdxChartControl
   Left = 0
   Top = 0
   Width = 624
   Height = 441
   Align = alClient
   Titles = <>
   object dxChartControl1XYDiagram1: TdxChartXYDiagram
     object dxChartControl1XYSeries1: TdxChartXYSeries
       Caption = '2018'
       DataBindingType = 'DB'
       DataBinding.DataSource = DataSource1
       DataBinding.ArgumentField.FieldName = 'Region'
       DataBinding.ValueField.FieldName = '2018'
       ViewType = 'Bar'
       ShowInLegend = Diagram
       ColorSchemeIndex = 0
     end
     object dxChartControl1XYSeries2: TdxChartXYSeries
       Caption = '2019'
       DataBindingType = 'DB'
       DataBinding.DataSource = DataSource1
       DataBinding.ArgumentField.FieldName = 'Region'
       DataBinding.ValueField.FieldName = '2019'
       ViewType = 'Bar'
       ShowInLegend = Diagram
       ColorSchemeIndex = 1
     end
     object dxChartControl1XYSeries3: TdxChartXYSeries
       Caption = '2020'
       DataBindingType = 'DB'
       DataBinding.DataSource = DataSource1
       DataBinding.ArgumentField.FieldName = 'Region'
       DataBinding.ValueField.FieldName = '2020'
       ViewType = 'Bar'
       ShowInLegend = Diagram
       ColorSchemeIndex = 2
     end
   end
 end
 object dxSkinController1: TdxSkinController
   SkinName = 'WXI'
   SkinPaletteName = 'Office Colorful'
   Left = 552
   Top = 72
 end
 object dxMemData1: TdxMemData
   Active = True
   Indexes = <>
   Persistent.Data = {
     5665728FC2F5285C8FFE3F040000001400000014000700526567696F6E000800
     0000060005003230313800080000000600050032303139000800000006000500
     32303230000104000000410073006900610001DE718A8EE4F21040016DE7FBA9
     F1121340010E2DB29DEF27154001090000004100750073007400720061006C00
     6900610001D5E76A2BF697FC3F01C364AA605452FF3F011FF46C567D2E024001
     060000004500750072006F00700065000130BB270F0BB50840013EE8D9ACFADC
     0A400158A835CD3BCE0D40010D0000004E006F00720074006800200041006D00
     6500720069006300610001FCA9F1D24DE20B4001ECC039234AFB0D40017B14AE
     47E1BA1040010D00000053006F00750074006800200041006D00650072006900
     630061000186C954C1A8A4F93F0176711B0DE02DFD3F01C7BAB88D06F00040}
   SortOptions = []
   Left = 552
   Top = 136
   object dxMemData1Region: TWideStringField
     FieldName = 'Region'
   end
   object dxMemData12018: TFloatField
     FieldName = '2018'
   end
   object dxMemData12019: TFloatField
     FieldName = '2019'
   end
   object dxMemData12020: TFloatField
     FieldName = '2020'
   end
 end
 object DataSource1: TDataSource
   DataSet = dxMemData1
   Left = 552
   Top = 200
 end

Delphi
C++

delphi

var
  ADiagram: TdxChartXYDiagram;
  ABarView: TdxChartXYSeriesBarView;
  I: Integer;
begin
  ADiagram := dxChartControl1.Diagrams[0] as TdxChartXYDiagram;
  ADiagram.BeginUpdate; // Initiates the following batch change
  try
    for I := 0 to ADiagram.SeriesCount - 1 do // Iterates through all bar series in the diagram
    begin
      ABarView := ADiagram.Series[I].View as TdxChartXYSeriesBarView;
      ABarView.ValueLabels.Visible := True; // Displays value labels for the current series
      ABarView.ValueLabels.Position := TdxChartBarValueLabelPosition.Top;
      ABarView.ValueLabels.LineLength := 30;
      ABarView.ValueLabels.Appearance.LineOptions.Width := 2.0;
      ABarView.ValueLabels.Appearance.FillOptions.Color := TdxAlphaColors.AliceBlue;
      ABarView.ValueLabels.Appearance.BorderThickness := 1.5;
      ABarView.ValueLabels.Appearance.FontOptions.Name := 'Calibri';
      ABarView.ValueLabels.Appearance.FontOptions.Size := 10;
      ABarView.ValueLabels.TextFormat := '{V:0.000} M'; // Defines a custom label formatting pattern
    end;
  finally
    ADiagram.EndUpdate; // Calls EndUpdate regardless of the batch operation's success
  end;
end;

cpp

TdxChartXYDiagram *ADiagram;
  TdxChartXYSeriesBarView *ABarView;
  // ...
  ADiagram = dynamic_cast<TdxChartXYDiagram*>(dxChartControl1->Diagrams[0]);
  ADiagram->BeginUpdate(); // Initiates the following batch change
  try
  {
    for(int i = 0; i < ADiagram->SeriesCount; i++) // Iterates through all series in the diagram
    {
      ABarView = dynamic_cast<TdxChartXYSeriesBarView*>(ADiagram->Series[i]);
      ABarView->ValueLabels->Visible = true; // Displays value labels for the current series
      ABarView->ValueLabels->Position = TdxChartBarValueLabelPosition::Top;
      ABarView->ValueLabels->LineLength = 30;
      ABarView->ValueLabels->Appearance->LineOptions->Width = 2.0f;
      ABarView->ValueLabels->Appearance->FillOptions->Color = TdxAlphaColors::AliceBlue;
      ABarView->ValueLabels->Appearance->BorderThickness = 1.5f;
      ABarView->ValueLabels->Appearance->FontOptions->Name = "Calibri";
      ABarView->ValueLabels->Appearance->FontOptions->Size = 10;
      ABarView->ValueLabels->TextFormat = "{V:0.000} M"; // Defines a custom label formatting pattern
    }
  }
  __finally
  {
    ADiagram->EndUpdate(); // Calls EndUpdate regardless of the batch operation's success
  }

Default Value

The TextFormat property’s default value is an empty string.

Simple Series

The default TextFormat property value indicates that a simple series point label displays an argument followed by a value separated by a colon and a space character:

The default simple point label formatting corresponds to the following formatting pattern: '{A}: {V}'.

XY Series

The default TextFormat property value indicates that an XY series point label displays only a series value as is:

The default XY point label formatting corresponds to the following pattern: '{V}'.