在 TeeChart 中存储对对象的引用

Question

我正在使用TeeChart和Delphi XE5，并利用BubbleSeries组件在图表中显示X/Y/Radius气泡。

我

正在使用我拥有的对象列表构建图表，动态计算这些对象的 X/Y/半径值，并使用 TBubbleSeries.AddBubble 方法插入它们。

问题是当我想在悬停/单击/等相应的气泡时对对象执行某些操作时。我使用 TChartSeries.Clicked 方法来找出单击了哪个气泡，但我返回的索引只能用于找出气泡的 xy/radius 值，而不是哪个对象发起它。

也许我错过了一些简单的东西，因为这似乎是任何图表库都应该轻松处理的东西。我尝试使用从 AddBubble 方法返回的索引，但此索引仅在执行对 AddBubble 的另一次调用之前有效，此时，内部列表似乎已重新排序。

编辑：被要求提供一些代码，就在这里！

procedure TBubbleReportForm.ChartMouseMove(Sender: TObject; Shift: TShiftState; X, Y: Integer);
var
  Index: Integer;
  Device: TDevice;
begin
  Index := BubbleSeries.Clicked(X,Y);
  if Index = -1 then
  begin
    BubbleChart.ShowHint := False;
    Exit;
  end;
  // This does not work as indexing does seems to correspond to the order which the bubbles was added.
  Device := FDevices[Index];

  BubbleChart.Hint := Device.Name;
  BubbleChart.ShowHint := True;
end;

procedure TBubbleReportForm.FormCreate(Sender: TObject);
var
  Device: TDevice;
begin

  BubbleChart.OnMouseMove := ChartMouseMove;
  // FDevices is of TObjectList type.
  for Device in FDevices do
  begin
    BubbleSeries.AddBubble(Device.CalculateXVal,Device.CalculateYVal,Device.CalculateRadius);
  end;
end;

Answer 1

我会使用一个通用的TObjectList。或者一个后代 og a TObjectList。

首先，列出

你的BoubleObject，并列出它们。在下面的示例中，我刚刚使用了一个虚拟实现：

unit BubbleU;
interface
uses
  System.Generics.Collections, System.SysUtils, Vcl.Graphics;
{$M+}
type
  TBubble = class
  private
    FX: Double;
    FRadius: Double;
    FY: Double;
    FLabelText: String;
    FColor: TColor;
    FIndex: Integer;
    FChartIndex: Integer;
    procedure SetChartIndex(const Value: Integer);
  protected
    procedure DoCalculation;
  public
    constructor Create(aIndex: Integer); reintroduce;
  published
    property X: Double read FX;
    property Y: Double read FY;
    property Radius: Double read FRadius;
    property LabelText: String read FLabelText;
    property Color: TColor read FColor;
    property ChartIndex: Integer read FChartIndex write SetChartIndex;
  end;
  TBubbleList = class(TObjectList<TBubble>)
  public
    function ElementFormChartIndex(ChartIndex: Integer): TBubble; overload;
  end;
implementation
{ TBubble }
constructor TBubble.Create(aIndex: Integer);
begin
  inherited Create;
  FIndex := aIndex;
  DoCalculation;
end;
procedure TBubble.DoCalculation;
begin
  FX := FIndex;
  FY := FIndex;
  FRadius := 1;
  FColor := clRed;
  FLabelText := 'Index: ' + FIndex.ToString;
end;
procedure TBubble.SetChartIndex(const Value: Integer);
begin
  FChartIndex := Value;
end;
{ TBubbleList }
function TBubbleList.ElementFormChartIndex(ChartIndex: Integer): TBubble;
var
  Element : TBubble;
begin
  for Element in Self do
    if Element.FChartIndex = ChartIndex then
      Exit(element);
  Exit(nil);
end;
end.

下一页 扩展您的 TB 系列

unit BubbleSeriesExtention;
interface
uses
  System.Classes, System.SysUtils,
  VclTee.BubbleCh,
  BubbleU;
type
  TBubbleSeries = class(VclTee.BubbleCh.TBubbleSeries)
  strict private
    FBoubleList: TBubbleList;
  public
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
    function AddBubble(aBubble: TBubble): Integer; reintroduce;
  published
    property BoubleList : TBubbleList read FBoubleList;
  end;
implementation
{ TBubbleSeries }
function TBubbleSeries.AddBubble(aBubble: TBubble): Integer;
begin
  aBubble.ChartIndex := Inherited AddBubble(aBubble.X, aBubble.Y, aBubble.Radius, aBubble.LabelText, aBubble.Color);
  FBoubleList.Add(aBubble);
  Result := aBubble.ChartIndex;
end;
constructor TBubbleSeries.Create(AOwner: TComponent);
begin
  inherited;
  FBoubleList := TBubbleList.Create(True);
end;
destructor TBubbleSeries.Destroy;
begin
  FreeAndNil(FBoubleList);
  inherited;
end;
end.

最后在以下来源使用它：

将 BubbleSeriesExtensionion 添加到 VclTee.BubbleCh 之后的使用列表

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, VclTee.TeeGDIPlus, VclTee.TeEngine,
  VclTee.Series, VclTee.BubbleCh, Vcl.ExtCtrls, VclTee.TeeProcs, VclTee.Chart,
  BubbleU, BubbleSeriesExtention;

并使用它：

type
  TForm4 = class(TForm)
    Chart1: TChart;
    BubbleSeries: TBubbleSeries;
    procedure FormCreate(Sender: TObject);
    procedure Chart1MouseMove(Sender: TObject; Shift: TShiftState; X, Y: Integer);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
var
  Form4: TForm4;
implementation
{$R *.dfm}
procedure TForm4.Chart1MouseMove(Sender: TObject; Shift: TShiftState; X, Y: Integer);
var
  Index: Integer;
  Bouble: TBubble;
begin
  Index := BubbleSeries.Clicked(X, Y);
  if index < 0 then
    exit;
  Bouble := BubbleSeries.BoubleList.ElementFormChartIndex(Index);
  Caption := Bouble.LabelText;
end;
procedure TForm4.FormCreate(Sender: TObject);
var
  i: Integer;
begin
  //Add dummy data
  for i := 0 to 9 do
    BubbleSeries.AddBubble(TBubble.Create(i));
end;
end.

这个解决方案有一个优点，你可以一直访问你的对象，当你的BubbleSeries被摧毁时，你的对象也会被摧毁，用于计算其中的元素。 并给你一种垃圾收集

Answer 2

您可以像这样利用未使用的 AXLabel 参数：

for DevIndex := 0 to DeviceCount - 1 do begin
    Device := FDevices[DevIndex]; 
    BubbleSeries.AddBubble(Device.CalculateXVal,Device.CalculateYVal, Device.CalculateRadius, IntToStr(DevIndex));
end; 
// to avoid labels' text ox X-Axis:
Chart1.BottomAxis.LabelStyle := talValue; 
  //in Clicked:
   DeviceIndex := StrToInt(BubbleSeries.Labels[Index]);