Firemonkey Grid Control - 根据值设置单元格样式(通过 OnGetValue 函数调用) [英] Firemonkey Grid Control - Styling a Cell based on a value (via the OnGetValue function call)

问题描述

我正在寻找推荐的解决方案来设置由 OnGetValue 调用绘制的 TGrid 单元格的样式(调用它来绘制视图中的单元格).作为背景，Mike 的出色回应展示了如何在创建单元格时简单地应用 tAlign 属性；但我的下一个挑战是为单元格内容着色.

I am looking for recommended solution to style a TGrid cell that is being drawn by the OnGetValue call (that is called to paint the cells in view). For background, an excellent response by Mike, showed how to simply apply a tAlign property when the cell is created; but my next challenge is colouring the cell contents.

以前的发帖/回答

目标是更改我即将作为单元格值"返回的值的单元格属性(字体、样式、颜色等).在下面的例子中；它将对正在返回的 OnGetValue值"应用样式.很可能我们必须通过 FM 样式表来做到这一点；或者我们可以直接获得 TText 属性吗?理想情况下，这两种情况都很好 - 但在这个阶段我会采取任何一种解决方案......(;->

The objective is to change the cell attributes (Font, style, colour etc...) of the value I am about to return as the cell "Value". In the example below; it would be applying a style to the OnGetValue "value" that is being returned. It may well be that we have to do this via a FM Stylesheet; or can we get directly to the TText attributes? Ideally, both scenarios would be great - but at this stage I will take either solution... (;->

unit Unit1;

interface

uses
  System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants,
  FMX.Types, FMX.Controls, FMX.Forms, FMX.Dialogs, FMX.Objects, FMX.Grid,
  FMX.Layouts, FMX.Edit;

type
  TForm1 = class(TForm)
    Grid1: TGrid;
    Button1: TButton;
    StyleBook1: TStyleBook;
    procedure Grid1GetValue(Sender: TObject; const Col, Row: Integer;
      var Value: Variant);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

  TStringColNum = class(TStringColumn)
  private
    function CreateCellControl: TStyledControl; override;
  published
  end;

var
  Form1: TForm1;

implementation

{$R *.fmx}

function TStringColNum.CreateCellControl: TStyledControl;
begin
  Result:=TTextCell.Create(Self);
  TTextCell(Result).TextAlign := TTextAlign.taTrailing;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  Grid1.AddObject(TStringColumn.Create(Self));
  Grid1.AddObject(TStringColNum.Create(Self)); // Right Aligned column?

  Grid1.RowCount:=5000;
  Grid1.ShowScrollBars:=True;
end;

procedure TForm1.Grid1GetValue(Sender: TObject; const Col, Row: Integer;
  var Value: Variant);
begin
  if Col=0 then
    Value:='Row '+IntToStr(Row);

  if Col=1 then
    Value := 'Row '+IntToStr(Row);

// Apply style based on value ?

end;

end.

提前非常感谢，伊恩.

推荐答案

首先，道歉.在我对你最后一个问题的回答中， CreateCellControl 应该调用继承来创建单元格.我已经修改了答案.

Firstly, an apology. In my answer to your last question, CreateCellControl should have called inherited to create the cell. I've amended my answer.

至于这个问题，我已经在 FireMonkey Cells 上上传了我的博文 - http://monkeystyler.com/blog/entry/firemonkey-grid-basics-custom-cells-and-columns - 它涵盖了上一个答案中的内容，还涵盖了创建自定义细胞控制.在继续之前，您需要阅读该内容.我等着.

As for this question, I've uploaded my blog posting on FireMonkey Cells - http://monkeystyler.com/blog/entry/firemonkey-grid-basics-custom-cells-and-columns - it covers the stuff from the previous answer, and also covers creating custom cell controls. You'll need to read that before your proceed. I'll wait.

...

现在回来?很好.

从博文中的示例开始.

除了，我更新了 TFinancialCell 以直接从 TTextCell(当然是 TEdit)继承，这更有意义并且更简单的样式.

Except, that I've updated the TFinancialCell to inherit directly from TTextCell (which of course is a TEdit), which makes far more sense and is far simpler to style.

所以，更新 TFinancialCell:

So, update the TFinancialCell:

type TFinancialCell = class(TTextCell)
  private
    FIsNegative: Boolean;
    FIsImportant: Boolean;
  protected
    procedure SetData(const Value: Variant); override;
    procedure ApplyStyle;override;
    procedure ApplyStyling;
  public
    constructor Create(AOwner: TComponent); override;
  published
    property IsNegative: Boolean read FIsNegative;
    property IsImportant: Boolean read FIsImportant;
  end;

以上代码:

procedure TFinancialCell.ApplyStyle;
var T: TFMXObject;
begin
  inherited;
  ApplyStyling;
end;

procedure TFinancialCell.ApplyStyling;
begin
  if IsNegative then
    FontFill.Color := claRed
  else
    FontFill.Color := claBlack;
  Font.Style := [TFontStyle.fsItalic];
  if IsImportant then
    Font.Style := [TFontStyle.fsBold]
  else
    Font.Style := [];
  if Assigned(Font.OnChanged) then
    Font.OnChanged(Font);
  Repaint;
end;

constructor TFinancialCell.Create(AOwner: TComponent);
begin
  inherited;
  TextAlign := TTextAlign.taTrailing;
end;

procedure TFinancialCell.SetData(const Value: Variant);
var F: Single;
  O: TFMXObject;
  S: String;
begin
  S := Value;
  FIsImportant := S[1] = '#';
  if IsImportant then
    S := Copy(Value,2,MaxInt)
  else
    S := Value;

  F := StrToFloat(S);
  inherited SetData(Format('%m', [F]));
  FIsNegative := F < 0;
  ApplyStyling;
end;

最后，更新 GetValue 事件处理程序:

And finally, update the GetValue event handler:

procedure TForm1.Grid1GetValue(Sender: TObject; const Col, Row: Integer;
  var Value: Variant);
var Cell: TStyledControl;
begin
  if Col = 0 then
    Value := Row
  else if Col = 1 then
  begin
    Value := FloatToStr(Data[Row]);
    if Value > 30 then
      Value := '#'+Value;
  end;
end;

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