delphi中的dll文件，有个函数，addnumber，就是求2个数的和
我在vb中是这样调用的：
Private Declare Sub AddNumber Lib "TestDll.dll" (x As Integer, y As Integer)
Private Sub Command1_Click()
 Dim a As Integer
 Dim b As Integer
 Dim sum As Integer
 a = Text1.Text
 b = Text2.Text
 Call AddNumber(a, b)
End Sub
这样好像不报错，可是我要在text3中得到text1和text2的和，接下来怎么做，教教