VB.NET Nested With statements from different scope

问题:

I am wondering if this is possible. I have a List Table (lstTable) that is on the same form that I am trying to fill in with information from a public structure (ELEM_DATA). I understand nested with statements will work if it is within the same scope but how can I do this with example 2 below:

Example 1:

With me.lstTable.Items(RECORD)
     .SubItems(1).text = ELEM_DATA(RECORD).name
     .SubItems(2).text = ELEM_DATA(RECORD).number
end with

Example 2:

With me.lstTable.Items(RECORD)
     With ELEM_DATA(RECORD)
     .SubItems(1).text = .name
     .SubItems(2).text = .number
     end with
end with

I didnt know if it is possible or if it would be as simple as changing (.name) to something else.

回答1:

Nested With statements work (see comment about conflicts). Unfortunately you can't use the outer members inside the inner with. But since your outer WITH is a refernce type you could use a local variable to "alias" it as you suggest in you comment.

Dim l = me.lstTable.Items(RECORD) ' requires 2008 and option infer
With ELEM_DATA(RECORD)
   l.SubItems(1).text = .name
End With

Here's a link to show how nested WITH statements can used.

http://ideone.com/agjne

回答2:

'EXAMPLE:

With New Object() {1, 2} 'With block 1
     Dim debug_1 As Object = .ToArray(0) 'Value 1 from object of block 1
         With New Object() {3, 4}  'With block 2
                 Dim debug_2 As Object = .ToArray(0)  'Value 3 from block 2
                 'How get 2 from block 1 of Object() {1, 2}?
                 '>>>
         End With
End With
'SOLUTION
With New Object() {1, 2}    
     With New Object() {3, 4}.Concat(.ToArray)
          Dim debug_3 As Object = .ToArray(3)  'got value 2 from outer WITH block 1 [Object() {1, 2}]
          '---//---//---
     End With
     '---//---//---
End With