WM_KEYDOWN和WM_KEYUP的使用
通过这两个消息可以模拟键盘事件。
相关函数：
MapVirtualKey: The MapVirtualKey function translates (maps) a virtual-key code into a scan code or character value, or translates a scan code into a virtual-key code.
VkKeyScan: The VkKeyScan function translates a character to the corresponding virtual-key code and shift state for the current keyboard.
PostMessage，SetForegroundWindow
WM_KEYDOWN和WM_KEYUP的 wParam就是虚拟键码，MSDN上可以查到，也可以通过VkKeyScan将一个字符转换成虚拟键码和shift状态的结合。
lParam的0到15位为该键在键盘上的重复次数，经常设为1，即按键1次；16至23位为键盘的扫描码，通过MapVirtualKey配合其参数可以得到；24位为扩展键，即某些右ALT和CTRL；29、30、31位按照说明设置即可（第30位对于keydown在和shift等结合的时候通常要设置为1）。
Specification of WM_KEYDOWN:
wParam
- Specifies the virtual-key code of the nonsystem key.
- lParam
- Specifies the repeat count, scan code, extended-key flag, context code, previous key-state flag, and transition-state flag, as shown in the following table.
- 0-15
- Specifies the repeat count for the current message. The value is the number of times the keystroke is autorepeated as a result of the user holding down the key. If the keystroke is held long enough, multiple messages are sent. However, the repeat count is not cumulative.
- 16-23
- Specifies the scan code. The value depends on the OEM.
- 24
- Specifies whether the key is an extended key, such as the right-hand ALT and CTRL keys that appear on an enhanced 101- or 102-key keyboard. The value is 1 if it is an extended key; otherwise, it is 0.
- 25-28
- Reserved; do not use.
- 29
- Specifies the context code. The value is always 0 for a WM_KEYDOWN message.
- 30
- Specifies the previous key state. The value is 1 if the key is down before the message is sent, or it is zero if the key is up.
- 31
- Specifies the transition state. The value is always zero for a WM_KEYDOWN message.
- Specification of WM_KEYUP:
- wParam
- Specifies the virtual-key code of the nonsystem key.
- lParam
- Specifies the repeat count, scan code, extended-key flag, context code, previous key-state flag, and transition-state flag, as shown in the following table.
- 0-15
- Specifies the repeat count for the current message. The value is the number of times the keystroke is autorepeated as a result of the user holding down the key. The repeat count is always one for a WM_KEYUP message.
- 16-23
- Specifies the scan code. The value depends on the OEM.
- 24
- Specifies whether the key is an extended key, such as the right-hand ALT and CTRL keys that appear on an enhanced 101- or 102-key keyboard. The value is 1 if it is an extended key; otherwise, it is 0.
- 25-28
- Reserved; do not use.
- 29
- Specifies the context code. The value is always 0 for a WM_KEYUP message.
- 30
- Specifies the previous key state. The value is always 1 for a WM_KEYUP message.
- 31
- Specifies the transition state. The value is always 1 for a WM_KEYUP message.
Examples:
1 char ch = ...;
2 SHORT tmp = VkKeyScan(ch);
3 WPARAM wParam = tmp & 0xFF;
4 LPARAM lParam = 1;
5 lParam += MapVirtualKey(wParam, MAPVK_VK_TO_VSC) << 16;
6 bool shift = (tmp & 0x0100) == 0x0100 ? true : false;
7 //未考虑SHIFT，大小写的区分需通过SHIFT，注意设置第29位，可用Spy++捕获消息查看，此处只作备忘用
8 PostMessage(h_wnd, WM_KEYDOWN, wParam, lParam);
9 lParam += 1 << 30;
10 lParam += 1 << 31;
11 PostMessage(h_wnd, WM_KEYUP, wParam, lParam);
用keybd_event实现：
1 char ch = ...;
2 SHORT tmp = VkKeyScan(ch);
3 BYTE vk = tmp & 0xFF;
4 bool shift = (tmp & 0x0100) == 0x0100 ? true : false;
5 if (shift) {
6 keybd_event(VK_SHIFT, MapVirtualKey(VK_SHIFT, MAPVK_VK_TO_VSC), 0, 0);
7 }
8 keybd_event(vk, MapVirtualKey(vk, MAPVK_VK_TO_VSC), 0, 0);
9 keybd_event(vk, MapVirtualKey(vk, MAPVK_VK_TO_VSC), KEYEVENTF_KEYUP, 0);
10 if (shift) {
11 keybd_event(VK_SHIFT, MapVirtualKey(VK_SHIFT, MAPVK_VK_TO_VSC), KEYEVENTF_KEYUP, 0);
12 }
