VB代码中KeyAscii具体是怎么用的，是什么意思？

VB代码中KeyAscii具体是怎么用的，是什么意思？

使用案例：
Private Sub Form_KeyDown(KeyCode As Integer, Shift As Integer)
If Chr(KeyCode) = "A" Then Image1.Left = Image1.Left - 100
If Chr(KeyCode) = "D" Then Image1.Left = Image1.Left + 100
End Sub
Private Sub Form_KeyPress(KeyAscii As Integer)
If Chr(KeyAscii) = "w" Then Image1.Top = Image1.Top - 100
If Chr(KeyAscii) = "s" Then Image1.Top = Image1.Top + 100
End Sub
例一：
Private Sub Form_KeyDown(KeyCode As Integer, Shift As Integer)
If KeyCode = vbKeyUp Then you.Top = You.Top - 10
If KeyCode = vbKeyDown Then You.Top = You.Top + 10

If KeyCode = vbKeyleft Then you.Top = You.left - 10
If KeyCode = vbKeyright Then You.Top = You.left + 10
End Sub
例二：
Private Sub Form_KeyDown(KeyCode As Integer, Shift As Integer)
If KeyCode = 37 Then pig.Left = pig.Left - 10
If KeyCode = 38 Then pig.Top = pig.Top - 10
If KeyCode = 39 Then pig.Left = pig.Left + 10
If KeyCode = 40 Then pig.Top = pig.Top + 10
End Sub
例三：
Private Sub Form_KeyPress(KeyAscii As Integer)
if chr(keyascii)="a" then pig.Left = pig.Left - 10
if chr(keyascii)="d" then pig.Left = pig.Left + 10
if chr(keyascii)="w" then pig.top = pig.top - 10
if chr(keyascii)="s" then pig.top = pig.top + 10
end sub

KeyAscii 是一个接收键盘向程序发送按键按下时的Ascii码的变量...其实它没有什么神秘,它仅仅是一个传递的变量而已....但它有一个特别之处就是这是一个固定的变量,既不能用其它字符代替...

前面说的不对
我说个例子就打破他的说法了（汉字也有对应的ascii码，键盘没汉字吧！)
keyascii表示你按下的键后的字符代码（字符AScii码）
上面也给了例子，例子是对的！但他的说法应该改正为我的说法了！

我暂时保留我的看法！