可以左右居中對齊並可設定DisplayFormat的Edit控制元件 (轉)

可以左右居中對齊並可設定DisplayFormat的Edit控制元件 (轉)[@more@]

 

 

歡迎測試！

to:liang_z@163">liang_z@163.net

unit OWEdit;

interface

uses
  , Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls;

type
  TInputDataType = (tFloat,tInteger,tAll);

type
  TOWEdit = class(TEdit)
  private
  { Private declarations }
  FCanvas : TCanvas;
  FDataType: TInputDataType;
  FAlignment : TAlignment;
  FDisplayFormat : String;
  FDeciNum : ;
  FDisplayText : String;
  procedure WMPaint(var Message: TWMPaint); message WM_PAINT;
  protected
  { Protected declarations }
  procedure SetDataType(Value:TInputDataType);
  procedure SetAlignment(Value:TAlignment);
  procedure SetDisplayFormat(Value:String);
  procedure ClipPaste(var M:TMessage); Message WM_PASTE;
  procedure PaintWindow(DC: HDC); overr;
  procedure Paint; virtual;
  procedure WMExit(var Message:TWMKillFocus);Message WM_KILLFOCUS;
  procedure GetDisplayText;
  procedure ShowDisplayText;
  function  GetDeciLast:integer;
  public
  { Public declarations }
  OldText : String;
  property Text;
  property Canvas: TCanvas read FCanvas;
  constructor Create(AOwner: TComponent); override;
  destructor Destroy(); override;
  procedure KeyPress(var Key: Char); override;
  procedure KeyDown(var Key: Word; Shift: TShiftState); override;
  published
  { Published declarations }
  property DataType: TInputDataType read fDataType write SetDataType default tFloat;
  property Alignment: TAlignment read FAlignment write SetAlignment default taLeftJustify;
  property DisplayFormat: string read FDisplayFormat write SetDisplayFormat;
  end;

procedure Register;

implementation

procedure Register;
begin
  RegisterComponents('Ourway', [TOWEdit]);
end;

constructor TOWEdit.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
  Text := '0';
  FCanvas := TControlCanvas.Create;
  TControlCanvas(FCanvas).Control := Self;
  FDeciNum := 9999;
end;

destructor TOWEdit.Destroy();
begin
  FCanvas.Free;
  inherited Destroy();
end;

procedure TOWEdit.SetDataType(Value:TInputDataType);
begin
  If Value<>fDataType Then
  begin
  fDataType := Value;
  Case Value of
  tAll: Text := '';
  tFloat: Text:='0.0';
  tInteger: Text:='0';
  end;
  ShowDisplayText;
  Invalidate;
  end;
end;

procedure TOWEdit.SetAlignment(Value:TAlignment);
begin
  If Value<>FAlignment Then
  begin
  FAlignment := Value;
  Invalidate;
  end;
end;

procedure TOWEdit.SetDisplayFormat(Value: string);
begin
  If Value<>FDisplayFormat Then
  begin
  FDisplayFormat := Value;
  if Trim(Value)<>'' then
  FDeciNum := Length(Value)-Pos('.',Value)+1
  else
  FDeciNum := 9999;
  ShowDisplayText;
  Invalidate;
  end;
end;

procedure TOWEdit.KeyDown(var Key: Word; Shift: TShiftState);
begin
  if Key = VK_DELETE then
  if Self.SelStart=pos('.',Self.Text)-1 then
  Key := 0;
  inherited KeyDown(Key,Shift);
end;
procedure TOWEdit.KeyPress(var Key: Char);
var
  kv: Integer;
begin
  kv := Ord(Key);
  case fDataType of
  tInteger:
  if (((kv>58) or (kv<48)) and (kv<>3) and (kv<>22) and (kv<>8) and (kv<>13)) then
  Key := chr(0);
  tFloat:
  begin
  if (((kv>58) or (kv<48)) and (kv<>3) and (kv<>22) and (kv<>46) and (kv<>8) and (kv<>13)) then
  Key := chr(0)
  else
  begin
  if (kv=46) and (Pos('.',self.Text)>0) then//已有小數點
  Key := chr(0)
  else
  if MaxLength<1 then//小數點前面位數不定
  begin
  if ((GetDeciLast>=FDeciNum) and (kv<>8)) then //退格鍵
  if ((self.SelLength=0)and(pos('.',copy(Self.Text,1,self.SelStart))>0))then
  Key := chr(0);
  end
  else//輸入總長度已定
  begin
  if pos('.',copy(self.Text,1,self.selStart))<1 then
  begin//游標在小數點之前
  if ((self.SelStart>=MaxLength-FDeciNum)and(kv<>8)and(kv<>46)) then
  Key := chr(0);
  end
  else
  begin//游標在小數點之後
  if ((GetDeciLast>=FDeciNum) and (kv<>8) and (self.SelLength=0)and(pos('.',copy(Self.Text,1,self.SelStart))>0)) then
  Key := chr(0);
  end;
  end;
  end;
  end;
  else
  end;
  if (kv=8)and(Self.SelStart>0)and(Self.Text[self.SelStart]='.')and(GetDeciLast>1) then
  Key := chr(0);
  //還有一個Delete鍵沒有截獲！如果用此鍵刪除小數點，還是有可能出錯的。
  //搞定！用KeyDown override
  inherited KeyPress(Key);
end;

procedure TOWEdit.ClipPaste(var M:TMessage);
begin
  if fDataType=tAll then
  inherited;
end;

procedure TOWEdit.WMPaint(var Message: TWMPaint);
begin
  inherited;
  PaintWindow(Message.DC);
end;

procedure TOWEdit.PaintWindow(DC: HDC);
begin
  FCanvas.Lock;
  try
  FCanvas.Handle := DC;
  try
  TControlCanvas(FCanvas).UpdateTextFlags;
  Paint;
  finally
  FCanvas.Handle := 0;
  end;
  finally
  FCanvas.Unlock;
  end;
end;

procedure TOWEdit.Paint;
begin
  if not Focused then
  begin
  ShowDisplayText;
  end
  else
  inherited;
end;

procedure TOWEdit.WMExit(var Message:TWMKillFocus);
begin
  inherited;
  ShowDisplayText;
end;

procedure TOWEdit.GetDisplayText;
var
  ShowText : String;
begin
  ShowText := Text;
  if FDataType<>tAll then
  begin
  if Trim(ShowText)='' then
  ShowText := '0';
  if FDatatype=tFloat then
  ShowText := FormatFloat(FDisplayFormat,StrToFloat(ShowText))
  else
  ShowText := FormatFloat(FDisplayFormat,StrToInt(ShowText));
  end;
  FDisplayText := ShowText;
end;

procedure TOWEdit.ShowDisplayText;
var
  Rect : TRect;
  x,y : Integer;
begin
  GetDisplayText;
  Canvas.Lock;
  try
  Rect.Left := 1;
  Rect.Top := 1;
  Rect.Right := Width-1;
  Rect.Bottom:= Height-1;
  Canvas.Font := Font;
  if not Enabled then
  Canvas.Font.Color := clGrayText;
  Canvas.Brush.Color:=Self.Color;
  Canvas.FillRect(Rect);
  y := 2; x := 2;
  Case FAlignment of
  taLeftJustify:;
  taRightJustify:
  x := Width-Canvas.TextWidth(FDisplayText)-5;
  else
  x := (Width-Canvas.TextWidth(FDisplayText)-5)div 2;
  end;
  Canvas.TextOut(x,y,FDisplayText);
  finally
  Canvas.Unlock;
  end;
end;

function TOWEdit.GetDeciLast:integer;
var
  i : Integer;
begin
  Result := 0;
  if Pos('.',Text)>0 then
  begin
  for i:=1 to Length(Text) do
  if Text[i]='.' then
  begin
  Result := Length(Text)-i+1;//Length(Copy(Text,i,Length(Text)-i));
  Exit;
  end;
  end;
end;

end.