DateTimePicker如何与Delphi自带Style同步

原文出处：DateTimePicker如何与Delphi自带Style同步 - 封三郎 - 博客园 (cnblogs.com)

Delphi 的 DateTimePicker 组件有一个CalColors属性，可以设置 DropDown 打开的日历节目的风格。但如果不使用 Delphi 自带的 Style，在这里设置属性看不到期望的效果。

而使用了 delphi 自带的style，效果又存在瑕疵——日历面板大小有问题。

如果把自带 style 的 client 项关闭，大小倒是对了，之前设置的MonthBackColor属性在边框上也体现出来了，但是和窗体的风格又不统一了。

网上一搜，Stack Overflow 给出了方案——去掉自动绘制 style，去提取 style 的相关元素来设置 CalColors 属性。

尝试一下，效果基本能接受了。记在这里备查。

http://stackoverflow.com/questions/10335310/style-properties-for-tdatetimepicker

unit Unit15;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.ImgList, Vcl.StdCtrls, Vcl.ComCtrls;

type
  TForm15 = class(TForm)
    DateTimePicker1: TDateTimePicker;
    procedure DateTimePicker1DropDown(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form15: TForm15;

implementation


{$R *.dfm}

uses
  Winapi.CommCtrl,
  Vcl.Styles,
  Vcl.Themes,
  uxTheme;

Procedure SetVclStylesColorsCalendar( DateTimePicker: TDateTimePicker);
Var
  LTextColor, LBackColor : TColor;
begin
   uxTheme.SetWindowTheme(DateTimePicker.Handle, '', '');//disable themes in the calendar
   //get the vcl styles colors
   LTextColor:=StyleServices.GetSystemColor(clWindowText);
   LBackColor:=StyleServices.GetSystemColor(clWindow);

   DateTimePicker.Color:=LBackColor;
   //set the colors of the calendar
   DateTimePicker.CalColors.BackColor:=LBackColor;
   DateTimePicker.CalColors.MonthBackColor:=LBackColor;
   DateTimePicker.CalColors.TextColor:=LTextColor;
   DateTimePicker.CalColors.TitleBackColor:=LBackColor;
   DateTimePicker.CalColors.TitleTextColor:=LTextColor;
   DateTimePicker.CalColors.TrailingTextColor:=LTextColor;
end;


procedure TForm15.DateTimePicker1DropDown(Sender: TObject);
var
  hwnd: WinAPi.Windows.HWND;
begin
  hwnd := SendMessage(TDateTimePicker(Sender).Handle, DTM_GETMONTHCAL, 0,0);
  uxTheme.SetWindowTheme(hwnd, '', '');//disable themes in the drop down window
end;

procedure TForm15.FormCreate(Sender: TObject);
begin
  SetVclStylesColorsCalendar( DateTimePicker1);
end;

end.