'定义变量
Private TxtFocus As New TextBox
'文本框获得焦点事件
Private Sub TextBox1_Enter(ByVal sender As Object, ByVal e As System.EventArgs) Handles TextBox1.Enter
TxtFocus = TextBox1
End Sub
'按钮事件
Private Sub Numeral1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Numeral1.Click
TxtFocus.Select()
SendKeys.Send("1")
End Sub