1.将DLL复制到工程下
2.添加如下代码
[DllImport("DLL.dll")] public static extern int Add(int a, int b); private void button1_Click(object sender, EventArgs e) { string str; str = Add(5,3).ToString(); MessageBox.Show(str); }
原文：http://www.cnblogs.com/yuqilihualuo/p/4199054.html