unit Ext_Image;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  ExtCtrls;

type
  TExtImage = class(TImage)
  private
    { Private declarations }
    FMouseOnObject: Boolean;  // Edit
    FOnMouseEnter: TNotifyEvent;  //Make the Mouse Enter and Leave available
    FOnMouseLeave: TNotifyEvent;
    FPicture1:TPicture;
    FPicture2:TPicture;
    procedure CMMouseEnter(var Msg:TMessage); message CM_MOUSEENTER;
    procedure CMMouseLeave(var Msg:TMessage); message CM_MOUSELEAVE;
    procedure SetPicture1(P:TPicture);
    procedure SetPicture2(P:TPicture);
  protected
    { Protected declarations }
    procedure MouseEnter; dynamic;  // Edit
    procedure MouseLeave; dynamic;  // Edit
  public
    { Public declarations }
    constructor Create(AOwner: TComponent); override;
  published
    { Published declarations }
    property OnMouseEnter: TNotifyEvent
        read FOnMouseEnter  // Edit
       write FOnMouseEnter;

    property OnMouseLeave: TNotifyEvent
        read FOnMouseLeave  // Edit
       write FOnMouseLeave;

    property  Picture1:TPicture read FPicture1 write SetPicture1;
    property  Picture2:TPicture read FPicture2 write SetPicture2;
  end;

procedure Register;

implementation

procedure TExtImage.CMMouseEnter(var Msg:TMessage);
begin
  inherited;
  if not FMouseOnObject then  // Edit
  begin
    Picture.Assign(Picture2);
    FMouseOnObject := True;
    MouseEnter;
  end;
end;

procedure TExtImage.CMMouseLeave(var Msg:TMessage);
begin
  inherited;
  if FMouseOnObject then  // Edit
  begin
    Picture.Assign(Picture1);
    FMouseOnObject := False;
    MouseLeave;
  end;
end;

procedure TExtImage.MouseEnter;  // Edit
begin
  if Assigned(FOnMouseEnter) then
    FOnMouseEnter(Self);
end;

procedure TExtImage.MouseLeave;  // Edit
begin
  if Assigned(FOnMouseLeave) then
    FOnMouseLeave(Self);
end;

procedure TExtImage.SetPicture1;
begin
  FPicture1.Assign(P);
  Picture.Assign(p);
end;

procedure TExtImage.SetPicture2;
begin
  FPicture2.Assign(P);
  Picture.Assign(p);
end;

constructor TExtImage.Create(AOwner: TComponent);
begin
inherited;
  FPicture1:=TPicture.Create;
  FPicture2:=TPicture.Create;
end;

procedure Register;
begin
  RegisterComponents('Ray Adams', [TExtImage]);
end;

end.

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    ExtImage1: TExtImage;
    Memo1: TMemo;
    procedure ExtImage1MouseEnter(Sender: TObject);
    procedure ExtImage1MouseLeave(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.ExtImage1MouseEnter(Sender: TObject);
begin
     Memo1.Lines.Add('enter');
end;

procedure TForm1.ExtImage1MouseLeave(Sender: TObject);
begin
     Memo1.Lines.Add('leave');
end;

end.

чтобы он всегда выполнялся корректно.

BOOL SetConnectionOptions(LPCTSTR conn_name,LPCTSTR proxy_full_addr)
{
    //conn_name: active connection name.
    //proxy_full_addr : eg "210.78.22.87:8000"
    INTERNET_PER_CONN_OPTION_LIST list;
    BOOL    bReturn;
    DWORD   dwBufSize = sizeof(list);
    // Fill out list struct.
    list.dwSize = sizeof(list);
    // NULL == LAN, otherwise connectoid name.
    list.pszConnection = conn_name;
    // Set three options.
    list.dwOptionCount = 3;
    list.pOptions = new INTERNET_PER_CONN_OPTION[3];
    // Make sure the memory was allocated.
    if(NULL == list.pOptions)
    {
        // Return FALSE if the memory wasn't allocated.
        OutputDebugString("failed to allocat memory in SetConnectionOptions()");
        return FALSE;
    }
    // Set flags.
    list.pOptions[0].dwOption = INTERNET_PER_CONN_FLAGS;
    list.pOptions[0].Value.dwValue = PROXY_TYPE_DIRECT |
        PROXY_TYPE_PROXY;

    // Set proxy name.
    list.pOptions[1].dwOption = INTERNET_PER_CONN_PROXY_SERVER;
    list.pOptions[1].Value.pszValue = proxy_full_addr;//"http://proxy:80";

    // Set proxy override.
    list.pOptions[2].dwOption = INTERNET_PER_CONN_PROXY_BYPASS;
    list.pOptions[2].Value.pszValue = "local";

    // Set the options on the connection.
    bReturn = InternetSetOption(NULL,
        INTERNET_OPTION_PER_CONNECTION_OPTION, &list, dwBufSize);

    // Free the allocated memory.
    delete [] list.pOptions;
    InternetSetOption(NULL, INTERNET_OPTION_SETTINGS_CHANGED, NULL, 0);
    InternetSetOption(NULL, INTERNET_OPTION_REFRESH , NULL, 0);
    return bReturn;
}
BOOL DisableConnectionProxy(LPCTSTR conn_name)
{
    //conn_name: active connection name.
    INTERNET_PER_CONN_OPTION_LIST list;
    BOOL    bReturn;
    DWORD   dwBufSize = sizeof(list);
    // Fill out list struct.
    list.dwSize = sizeof(list);
    // NULL == LAN, otherwise connectoid name.
    list.pszConnection = conn_name;
    // Set three options.
    list.dwOptionCount = 1;
    list.pOptions = new INTERNET_PER_CONN_OPTION[list.dwOptionCount];
    // Make sure the memory was allocated.
    if(NULL == list.pOptions)
    {
        // Return FALSE if the memory wasn't allocated.
        OutputDebugString("failed to allocat memory in DisableConnectionProxy()");
        return FALSE;
    }
    // Set flags.
    list.pOptions[0].dwOption = INTERNET_PER_CONN_FLAGS;
    list.pOptions[0].Value.dwValue = PROXY_TYPE_DIRECT  ;
    // Set the options on the connection.
    bReturn = InternetSetOption(NULL,
        INTERNET_OPTION_PER_CONNECTION_OPTION, &list, dwBufSize);
    // Free the allocated memory.
    delete [] list.pOptions;
    InternetSetOption(NULL, INTERNET_OPTION_SETTINGS_CHANGED, NULL, 0);
    InternetSetOption(NULL, INTERNET_OPTION_REFRESH , NULL, 0);
    return bReturn;
}