谁能告诉我setwindowlong 的一些实例用法？（第三，四个参数有点晕，大家来教教我）
比如
做透明窗体
做圆角窗体
等等
------解决方案--------------------
SetWindowuLong(Handle(This),-20,786688)
pb 11.5 就直接有透明属性了！
------解决方案--------------------
The SetWindowLong function changes an attribute of the specified window. The function also sets the 32-bit (long) value at the specified offset into the extra window memory.
Note This function has been superseded by the SetWindowLongPtr function. To write code that is compatible with both 32-bit and 64-bit versions of Microsoft Windows, use the SetWindowLongPtr function.
Syntax
LONG SetWindowLong( HWND hWnd,
int nIndex,
LONG dwNewLong
);
Parameters
hWnd
[in]
Handle to the window and, indirectly, the class to which the window belongs.
Windows 95/98/Me: The SetWindowLong function may fail if the window specified by the hWnd parameter does not belong to the same process as the calling thread.
nIndex
[in] Specifies the zero-based offset to the value to be set. Valid values are in the range zero through the number of bytes of extra window memory, minus the size of an integer. To set any other value, specify one of the following values.
GWL_EXSTYLE
Sets a new extended window style. For more information, see CreateWindowEx.
GWL_STYLE
Sets a new window style.
GWL_WNDPROC
Sets a new address for the window procedure.
Windows NT/2000/XP: You cannot change this attribute if the window does not belong to the same process as the calling thread.
GWL_HINSTANCE
Sets a new application instance handle.
GWL_ID
Sets a new identifier of the window.
GWL_USERDATA
Sets the user data associated with the window. This data is intended for use by the application that created the window. Its value is initially zero.
The following values are also available when the hWnd parameter identifies a dialog box.
DWL_DLGPROC
Sets the new address of the dialog box procedure.
DWL_MSGRESULT
Sets the return value of a message processed in the dialog box procedure.
DWL_USER
Sets new extra information that is private to the application, such as handles or pointers.
dwNewLong
[in] Specifies the replacement value.
Return Value
If the function succeeds, the return value is the previous value of the specified 32-bit integer.
If the function fails, the return value is zero. To get extended error information, call GetLastError.
If the previous value of the specified 32-bit integer is zero, and the function succeeds, the return value is zero, but the function does not clear the last error information. This makes it difficult to determine success or failure. To deal with this, you should clear the last error information by calling SetLastError(0) before calling SetWindowLong. Then, function failure will be indicated by a return value of zero and a GetLastError result that is nonzero.
Remarks
Certain window data is cached, so changes you make using SetWindowLong will not take effect until you call the SetWindowPos function. Specifically, if you change any of the frame styles, you must call SetWindowPos with the SWP_FRAMECHANGED flag for the cache to be updated properly.
If you use SetWindowLong with the GWL_WNDPROC index to replace the window procedure, the window procedure must conform to the guidelines specified in the description of the WindowProc callback function.
If you use SetWindowLong with the DWL_MSGRESULT index to set the return value for a message processed by a dialog procedure, you should return TRUE directly afterward. Otherwise, if you call any function that results in your dialog procedure receiving a window message, the nested window message could overwrite the return value you set using DWL_MSGRESULT.