VS2010 VB 调用DLL的步骤

第一步：用VS2010的类库模板的PUBLIC FUNCTION 建立DLL，生成DLL文件SUM.DLL

第二步：新建FORM WINDOWS窗体,添加引用SUM.DLL

第三步：在新建窗体里声明SUM.DLL  

Public Class Form1
    ' Public Declare Function jiafa1 Lib "ADD1" (ByVal a1 As Double, ByVal b1 As Double) As Double
    Dim mydll1 As SUM.ADD1   '声明sum.add1
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        mydll1 = New SUM.ADD1  '声明实例化
        TextBox3.Text = mydll1.jiafa1(TextBox1.Text, TextBox2.Text)   '调用SUM.DLL的函数
    End Sub
End Class

第四步：声明实例化

第五部：调用SUM.DLL的函数

附件：为SUM.DLL

Public Class ADD1
    Public Function jiafa1(ByVal a1 As Double, ByVal b1 As Double) As Double
        jiafa1 = a1 + b1
        MsgBox("加法成功")
    End Function
End Class