將新書添加到數組Books（）

Question

我必須將新書添加到數組Books（）中。我使用了一個文本文件來填充數組，現在我需要ReDim Preserve將一本新書添加到數組中。這是ReDim和For循環我有一個功能來做到這一點，但它不能正常工作。任何想法如何做到這一點。

Private Sub btnAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAdd.Click 

    Dim newBook As Book 
    newBook = EmptyBook() 

    ReDim Preserve Books(Books.Count) 

    For i As Integer = 0 To Books.Count - 1 
     Books(i) = newBook 
    Next 

End Sub 

Function EmptyBook() As Book 
    Dim Answer As Book 
    With Answer 
     .title = txtTitle.Text 
     .authorLastName = txtAuthor.Text 
     .year = CInt(txtYear.Text) 
     .value = CDec(txtValue.Text) 
    End With 
    Return Answer 
End Function 

Answer 1

嘗試以下操作：

Private Sub btnAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAdd.Click 

Dim newBook As Book 
newBook = EmptyBook() 

if Books is nothing then 
    ReDim Books(0) 
else 
    ReDim Preserve Books(Books.GetUpperBound(0) + 1) 
end if 

Books(Books.GetUpperBound(0)) = newBook 

End Sub