Visual Basic密钥监听器

Question

我正试图在Visual Basic（VS 2010）中编写一个程序来响应箭头键。我知道在Java中有关键的监听器，但不知道在VB中是否存在这样的事情以及如何对它进行编码。请给我看一些例子。 谢谢。

Answer 1

如果您正在执行winforms，请将表单的KeyPreview属性设置为true，然后设置KeyDown事件。您的代码将如下所示：

Dim previousKey As Keys? = Nothing 

Private Sub Form1_KeyDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles MyBase.KeyDown 
    If e.KeyCode = Keys.Up Then 
     'up arrow 
    End If 


    If e.KeyCode = Keys.Left Then 
     'left arrow 
     If Not previousKey Is Nothing And previousKey = Keys.Up Then 
      'Up arrow and then Left Arrow 
      MessageBox.Show("there, that's better") 
     End If 
    End If 

    If e.KeyCode = Keys.Right Then 
     'right arrow 
    End If 

    If e.KeyCode = Keys.Down Then 
     'down arrow 
    End If 

    'After everything is done set the current key as the previous key. 
    previousKey = e.KeyCode 
End Sub