C#中调用DLL

1.先把调用的DLL文件复制到执行文件的目录(调试时为DEBUG目录)
2.在需调用DLL的*.CS文件中using System.Runtime.InteropServices;
3.在类定义中用DllImport关键字进行声明函数接口
public class FrmQuickSearch : System.Windows.Forms.Form
 {
        [DllImport("JINCARD7.DLL")]
        public extern static int Rcard(StringBuilder rdata,int track);
......

4.引用:
            StringBuilder rdata = new StringBuilder(32);            
            int re = Rcard(rdata,1);

这里要注意如果函数参数为PChar型,如(Rcard(rdata:pchar;track:integer):integer;)则可在C#中将其声明为StringBuilder而不用String.

相关文章:http://support.microsoft.com/default.aspx?scid=kb;zh-cn;815065