ExtTextOut问题(100分)

Windows单元中此函数怎么用
function ExtTextOut(DC: HDC;
X, Y: Integer;
Options: Longint;
Rect: PRect;
Str: PChar;
Count: Longint;
Dx: PInteger): BOOL;
stdcall;
这句是什么意思
ExtTextOut(DC, X, Y, ETO_OPAQUE or ETO_CLIPPED, @rc, @Ch, 1, nil);
我要从哪里了解这些函数呢？

ExtTextOut
The ExtTextOut function draws a character string by using the currently
selected font, background color, and text color. An optional rectangle
may be provided, to be used for clipping, opaquing, or both.
BOOL ExtTextOut(
HDC hdc, // handle to device context
int X, // x-coordinate of reference point
int Y, // y-coordinate of reference point
UINT fuOptions, // text-output options
CONST RECT *lprc, // optional clipping and/or opaquing rectangle
LPCTSTR lpString, // points to string
UINT cbCount, // number of characters in string
CONST INT *lpDx // pointer to array of intercharacter spacing
// values
);
具体的含义，查MSDN。我觉得，MSDN是程序员必备的一样工具。

Delphi自带的Win32API帮助中就有
在你的编辑器中随便的地方键入ExtTextOut然后光标移动到这个字中间,用帮助键F1就能得到在线帮助

多人接受答案了。