下面是一段登陆时自动加载用户名的代码（我想是这样的）：

代码如下： 有些看不懂，请读帖子的人 帮我 “详细”讲解一下，先谢了！

Private Declare Function GetUserName Lib "advapi32.dll" Alias "GetUserNameA" (ByVal lpbuffer As String, nSize As Long) As Long

Public OK As Boolean

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Private Sub Form_Load()
Dim sBuffer As String
Dim lSize As Long

sBuffer = Space$(255)
lSize = Len(sBuffer)
Call GetUserName(sBuffer, lSize)
If lSize > 0 Then
txtUserName.Text = Left$(sBuffer, lSize)
Else
txtUserName.Text = vbNullString
End If
End Sub

关键是这个API函数怎么查？　　查　MSDN吗？

都是英文的，看着有点迷糊！还有别的办法吗？