unitfrmmain.pas

《Delphi百例》源码?禗elphi百例》源码

unit unitFrmMain;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  FileCtrl, StdCtrls, ExtCtrls, Buttons, Registry;

type
  TForm1 = class(TForm)
    SpeedButton1: TSpeedButton;
    SpeedButton2: TSpeedButton;
    Image1: TImage;
    FileListBox1: TFileListBox;
    DriveComboBox1: TDriveComboBox;
    DirectoryListBox1: TDirectoryListBox;
    procedure SpeedButton1Click(Sender: TObject);
    procedure SpeedButton2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.SpeedButton1Click(Sender: TObject);
begin
  if (filelistbox1.FileName = '') then {判断Filelistbox1中文件有没有被选中}
    Messagedlg('请先选择一幅位图', mtInformation, [mbOK], 0)
  else
    Image1.Picture.LoadFromFile(Filelistbox1.FileName); {加载图片文件并显示}
end;

procedure TForm1.SpeedButton2Click(Sender: TObject);
var
  Reg: Tregistry; {Tregistry 对象在Registry 单元中声明，需用Uses令引用Registry单元}
begin
  if (Filelistbox1.FileName = '') then
    Messagedlg('请先选择一幅位图', mtInformation, [mbOK], 0)
  else
    begin
      Reg := Tregistry.Create; {创建Tregistry对象的实例}
      Reg.Rootkey := Hkey_Current_User; {设置根键名称}
      // 打开Control Panel\Desktop 路径对应的主键
      Reg.OpenKey('Control Panel\Desktop', False);
      Reg.WriteString('TileWallPaper', '0');
      // 向TileWallpaper 和Wallpaper串覆盖写入新值
      Reg.WriteString('Wallpaper', FileListBox1.FileName);
      Systemparametersinfo(SPI_SETDESKWallpaper, 0, nil, SPIF_SendChange); {向Windows发送消息，通知Windows更换壁纸}
      Reg.CloseKey; {将更改内容写入注册表并关闭}
      Reg.Free; {释放对象}
    end;
end;

end.