---
title: "C# 用 VID 和 PID 自動連線 serialport"
description: "原本 C的 serial port function官方範例，是類似這樣的"
author: "kidneyweakx"
published: 2020-04-28T00:00:00.000Z
updated: 2026-06-02T17:25:09.833Z
lang: zh-TW
tags: ["程式筆記", "C#"]
canonical: https://kidneyweakx.com/blog/20log-0428-serial
---

# C# 用 VID 和 PID 自動連線 serialport

原本 C# 的 serial port function[官方範例](https://docs.microsoft.com/zh-tw/dotnet/api/system.io.ports.serialport?view=dotnet-plat-ext-3.1)，是類似這樣的

```C#
streamport = new SerialPort("COM3", bauadrate);
```

這種方法每次開啟都還要再去跟改port相當的麻煩，所以就找了別人針對windows寫的function，再返回靜態的 port string 給`SerialPort`，效果相當好。

```C#
// 有錯誤可能是你沒有 using Microsoft.Win32;或其他lib
 public static List<string> ComPortNames(String VID, String PID)
    {
        // 讀取PID和VID
        String pattern = String.Format("^VID_{0}.PID_{1}", VID, PID);
        Regex _rx = new Regex(pattern, RegexOptions.IgnoreCase);
        List<string> comports = new List<string>();
        RegistryKey rk1 = Registry.LocalMachine;
        RegistryKey rk2 = rk1.OpenSubKey("SYSTEM\\CurrentControlSet\\Enum");
        foreach (String s3 in rk2.GetSubKeyNames())
        {
            RegistryKey rk3 = rk2.OpenSubKey(s3);
            foreach (String s in rk3.GetSubKeyNames())
            {
                if (_rx.Match(s).Success)
                {
                    RegistryKey rk4 = rk3.OpenSubKey(s);
                    foreach (String s2 in rk4.GetSubKeyNames())
                    {
                        RegistryKey rk5 = rk4.OpenSubKey(s2);
                        RegistryKey rk6 = rk5.OpenSubKey("Device Parameters");
                        comports.Add((string)rk6.GetValue("PortName"));
                        // 獲取port name，如有多個相同設備，加入comports array
                    }
                }
            }
        }
        return comports;
    }
```

完整內容可參照下方連結😁
[code來源](https://www.codeproject.com/Tips/349002/Select-a-USB-Serial-Device-via-its-VID-PID)