关于控件属性的设置？

[xyz000]

我在VB中做了一个控件，在设计时定义了二个属性，代码如下，但是我在读取其属性时，其结果仍然为0。是我的LET方法做得不对吗？
代码：

dim offset as integer
dim startAdd as integer
Public Property Let startAdd(vnewvalue As String)
offset = vnewvalue
End Property
Public Property Get startAdd() As String
startAdd = offset
End Property
'数据长度
Public Property Let Dataleng(vnewvalue As String)
length = vnewvalue
End Property
Public Property Get Dataleng() As String
Dataleng = length
End Property

[realKK]

自制控件属性涉及：
UserControl_InitProperties(...)
UserControl_WriteProperties(...)
UserControl_ReadProperties(...)
PropertyChanged(...)