学习官方示例 - TApplication.OnShowHint

代码文件:

---

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    procedure FormCreate(Sender: TObject);
  private
    procedure DoShowHint(var HintStr: String; var CanShow: Boolean; var HintInfo: THintInfo);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
  Application.OnShowHint := DoShowHint;
  Label1.Hint := Label1.Caption;
  Label2.Hint := Label2.Caption;
  Label3.Hint := Label3.Caption;
  Label1.ShowHint := True;
  Label2.ShowHint := True;
  Label3.ShowHint := True;
end;

procedure TForm1.DoShowHint(var HintStr: String; var CanShow: Boolean; var HintInfo: THintInfo);
begin
  with HintInfo do
  begin
    if HintControl = Label1 then
    begin
      HintColor := clAqua;
      Dec(HintPos.X, 15);
      Dec(HintPos.Y, 60);
    end;
    if HintControl = Label3 then
    begin
      HintColor := clWebPeachPuff;
      Dec(HintPos.X, 15);
      Inc(HintPos.Y, 15);
    end;
  end;
end;

end.

窗体文件:

---

object Form1: TForm1
  Left = 0
  Top = 0
  Caption = 'Form1'
  ClientHeight = 128
  ClientWidth = 233
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = False
  Position = poDesktopCenter
  OnCreate = FormCreate
  PixelsPerInch = 96
  TextHeight = 13
  object Label1: TLabel
    Left = 24
    Top = 48
    Width = 65
    Height = 17
    Caption = 'Label1'
  end
  object Label2: TLabel
    Left = 95
    Top = 48
    Width = 65
    Height = 17
    Caption = 'Label2'
  end
  object Label3: TLabel
    Left = 166
    Top = 48
    Width = 65
    Height = 17
    Caption = 'Label3'
  end
end