// Delphi 下调用Windows API 创建窗体. //

program delphi;

uses
windows,
messages;

const
hellostr='Hello World!';

{$R delphi.res}


//窗口消息处理函数.
function MyWinProc(hWnd:THandle;uMsg:UINT;wParam,lParam:Cardinal):Cardinal;exp
ort;stdcall;

var
hdca,hdcb:THandle; //设备描述表句柄.
rect:TRect; //矩形结构.
font:HFont;
ps:TPaintStruct; //绘图结构.
begin
result:=0;
case uMsg of
WM_PAINT:
begin
hdca:=BeginPaint(hWnd,ps);
SetBkMode(hdca, Transparent);
SetBkColor(hdca,GetBkColor(hdca));
GetClientRect(hWnd,rect); //获取窗口客户区的尺寸.
DrawText(hdca,Pchar(hellostr),-1,rect,DT_SINGLELINE or DT_CENTER or DT
_VCENTER);
// TextOut(hdc,100,40,hellostr,Length(hellostr));
EndPaint(hWnd,ps);
end;
WM_Create:
begin
hdcb := GetDC(hWnd);
font := CreateFont(45, 0, 0, 0, FW_normal, 0, 0, 0, ansi_charset, out
_default_precis, clip_default_precis,
default_quality, 34, PChar('Arial'));
SelectObject(hdcb, font);
ReleaseDC(hWnd, hdcb);
end;
WM_DESTROY:
PostQuitMessage(0)
else
//使用缺省的窗口消息处理函数.
result:=DefWindowProc(hWnd,uMsg,wParam,lParam);
end;
end;

//主程序开始.

var
Msg :TMsg; //消息结构.
hWnd,hInst :THandle; //Windows 窗口
句柄.
WinClass :TWndClassEx; //Windows 窗口类结构.
begin
hInst:=GetModuleHandle(nil); // get the application instance
WinClass.cbSize:=SizeOf(TWndClassEx);
WinClass.lpszClassName:='MyWindow'; //类名.
WinClass.style:=CS_HREDRAW or CS_VREDRAW or CS_OWNDC;
WinClass.hInstance:=hInst; //程序的实例句柄.
//设置窗口消息处理函数.
WinClass.lpfnWndProc:=@MyWinProc; //窗口过程.
WinClass.cbClsExtra:=0; //以下两个域用于在类结构和Window
s内部保存的窗口结构
WinClass.cbWndExtra:=0; //中预留一些额外空间.
WinClass.hIcon:=LoadIcon(hInstance,MakeIntResource('MAINICON'));
WinClass.hIconsm:=LoadIcon(hInstance,MakeIntResource('MAINICON'));
WinClass.hCursor:=LoadCursor(0,IDC_Arrow);
//GetStockObject 获取一个图形对象,在这里是获取绘制窗口背景的刷子,返回一个白色刷
子的句柄.
WinClass.hbrBackground:=HBRUSH(GetStockObject(white_Brush));
WinClass.lpszMenuName:=nil; //指定窗口类菜单.

//向Windows 注册窗口类.
if RegisterClassEx(WinClass)=0 then
begin
MessageBox(0,'Registeration Error!','SDK/API',MB_OK);
Exit;
end;

//建立窗口对象.
hWnd:=CreateWindowEx(
WS_EX_OVERLAPPEDWINDOW, //扩展的窗口风格.
WinClass.lpszClassName, //类名.
'Hello Window', //窗口标题.
WS_OVERLAPPEDWINDOW, //窗口风格.
CW_USEDEFAULT, //窗口左上角相对于屏幕
左上角的初始位置x.
0, //....右y.
CW_USEDEFAULT, //窗口宽度x.
0, //窗口高度y.
0, //父窗口句柄.
0, //窗口菜单句柄.
hInst, //程序实例句柄.
nil); //创建参数指针.
if hWnd<>0 then
begin
ShowWindow(hWnd,SW_SHOWNORMAL); //显示窗口.
UpdateWindow(hWnd); //指示窗口刷新自己.
SetWindowPos(hWnd, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOMOVE + SWP_NOSIZ
E);

end
else
MessageBox(0,'Window not Created!','SDK/API',MB_OK);

//主消息循环程序.
while GetMessage(Msg,0,0,0) do
begin
TranslateMessage(Msg); //转换某些键盘消息.
DispatchMessage(Msg); //将消息发送给窗口过程.
end;
end.