使用AttachThreadInput API函数
Public Declare Function AttachThreadInput Lib "user32" Alias "AttachThreadInput" (ByVal idAttach As Long, ByVal idAttachTo As Long, ByVal fAttach As Long) As Long
idAttach - 欲连接线程的标识符
idAttachTo - 其他线程的标识符,应设为当前具有输入的线程
fAttach - true连接,false撤销连接