WinAPI: 输入光标相关的函数[4]

本例效果图:

---

代码文件:

---

unit Unit1;



interface



uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs;



type

  TForm1 = class(TForm)

    procedure FormMouseDown(Sender: TObject; Button: TMouseButton;

      Shift: TShiftState; X, Y: Integer);

    procedure FormKeyPress(Sender: TObject; var Key: Char);

  end;



var

  Form1: TForm1;



implementation



{$R *.dfm}



var

  str: string;

  x1,y1: Integer;



procedure TForm1.FormKeyPress(Sender: TObject; var Key: Char);

var

  x2: Integer;

begin

  HideCaret(Handle);

  Repaint;



  if Key = #8 then

  begin

    if Length(str) > 0 then

    SetLength(str, Length(str) - 1);

  end else str := str + Key;



  Text := str;



  Canvas.TextOut(x1, y1, str);

  x2 := x1 + Canvas.TextWidth(str);

  SetCaretPos(x2, y1);

  ShowCaret(Handle);

end;



procedure TForm1.FormMouseDown(Sender: TObject; Button: TMouseButton;

  Shift: TShiftState; X, Y: Integer);

begin

  str := '';

  DestroyCaret;

  CreateCaret(Handle, 0, 0, Canvas.TextHeight('A'));

  SetCaretPos(X,Y);

  ShowCaret(Handle);



  x1 := X;

  y1 := Y;

end;



end.


 
   

窗体文件:

---

object Form1: TForm1

  Left = 0

  Top = 0

  Caption = 'Form1'

  ClientHeight = 206

  ClientWidth = 339

  Color = clBtnFace

  Font.Charset = DEFAULT_CHARSET

  Font.Color = clWindowText

  Font.Height = -11

  Font.Name = 'Tahoma'

  Font.Style = []

  OldCreateOrder = False

  OnKeyPress = FormKeyPress

  OnMouseDown = FormMouseDown

  PixelsPerInch = 96

  TextHeight = 13

end