初次使用 net ，编辑框的内容怎么取得？
Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged

参数什么意思？

我想用msgbox显示刚键入的字符，怎么写？

[解决办法]
刚键入的字符? KeyDown事件配合TextChanged吧
感觉别扭...
[解决办法]
Private Sub TextBox1_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles TextBox1.KeyDown
MsgBox(ChrW(e.KeyData))
End Sub
或者用
Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
MsgBox(e.KeyChar)
End Sub

参数sender表示引发事件的对象(如TextBox1),e代表事件的相应信息(如被按下键的键值等).