Question

delphi如何模拟鼠标滚轮的往上和往下

如何模拟鼠标滚轮往上 往下的操作

Sendmessage(Handle,WM_MOUSEWHEEL,wParam,LPARAM);
网上找了一段 不知道怎么模拟往下 和往上 的操作 求解答

Answer 1

Handle是要实现鼠标滚动的窗口句柄.
知道句柄直接使用SendMessage发消息给窗口就行了
句柄可以用FindWindow这个API函数获得

追问

知道句柄直接使用SendMessage发消息给窗口就行了

发送消息的内容是？？
Sendmessage(Handle,WM_MOUSEWHEEL,wParam,LPARAM);

后面的2个参数怎么写 怎么判断是往上 还是往下 ？？

追答

可以查看MSDN或Delphi帮助文档
wParam
The high-order word indicates the distance the wheel is rotated, expressed in multiples or divisions of WHEEL_DELTA, which is 120. A positive value indicates that the wheel was rotated forward, away from the user; a negative value indicates that the wheel was rotated backward, toward the user.

The low-order word indicates whether various virtual keys are down. This parameter can be one or more of the following values.
MK_CONTROL
The CTRL key is down.
MK_LBUTTON
The left mouse button is down.
MK_MBUTTON
The middle mouse button is down.
MK_RBUTTON
The right mouse button is down.
MK_SHIFT
The SHIFT key is down.
MK_XBUTTON1
Windows 2000/XP: The first X button is down.
MK_XBUTTON2
Windows 2000/XP: The second X button is down.
lParam
The low-order word specifies the x-coordinate of the pointer, relative to the upper-left corner of the screen.

The high-order word specifies the y-coordinate of the pointer, relative to the upper-left corner of the screen.