如何关闭打开的端口?

[bulls5988]

我用c#打开了一个delphi编写的dll读卡，现在如何关闭我打开的端口

namespace offer
{
    public partial class Form1 : Form
    {
        public class DLL_Open
        {
            [DllImport("JINCARD7.dll", EntryPoint = "Init_com")]
            public static extern int Init_com(string flags);
            [DllImport("JINCARD7.dll", EntryPoint = "sele_exp_port")]
            public static extern int sele_exp_port(int coms,char exp);
            [DllImport("JINCARD7.dll", EntryPoint = "Rcard")]
            public static extern int Rcard(StringBuilder rdatas, int tracks);
            
        }

        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            
            string flags = "1,9600,N,8,1";
            int ret = DLL_Open.Init_com(flags);
            switch (ret)
            {
                case 1:
                    break;
                default:
                    break;
            //打开串口连接
            }

            DLL_Open.sele_exp_port(1,'b');
            StringBuilder rdatas = new StringBuilder(300);
            int result = DLL_Open.Rcard(rdatas,2);
            textBox1.Text = result.ToString();
            textBox2.Text = rdatas.ToString();
            switch (result)
            {
                case 1:
                    MessageBox.Show("读卡成功!卡号:" + rdatas.ToString().
Substring(1, 10), "提示", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
                    break;
                case -6:
                    MessageBox.Show("读卡超时!","提示", MessageBoxButtons.OK, 
MessageBoxIcon.Error);
                    break;
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
        //如何关闭打开的端口?
        }

      
    }

[wuyq11]

http://topic.csdn.net/u/20080421/21/e06c4f6d-faaf-405d-bfad-b50a935705ce.html

[bulls5988]

这样,有问题的的

public string flags;
flags = "1,9600,N,8,1";
int ret = DLL_Open.Init_com(flags);
System.Diagnostics.Process.Start(flags);

如果没点刷卡按钮就提示:
"尚未提供文件名，因此无法启动进程。"
如果点过刷卡按钮就提示:
"系统找不到指定的文件。"

[v风雪山神庙v]

[Quote=引用 1 楼 wuyq11 的回复:]
http://topic.csdn.net/u/20080421/21/e06c4f6d-faaf-405d-bfad-b50a935705ce.html
[/Quote]
+1

[bulls5988]

我2楼的什么地方错了啊?

[bulls5988]

也不对啊

public string ret;
private void button1_Click(object sender, EventArgs e)
{
flags = "1,9600,N,8,1";
int ret = DLL_Open.Init_com(flags);
System.Diagnostics.Process.Start(ref);
}
private void button2_Click(object sender, EventArgs e)
        {
            System.Diagnostics.Process.Start(ret);
        }