MVC中如何创建单例Model并复用ATEM Mini硬件连接？

我开发了一个连接ATEM Mini物理硬件的Model，搭配Controller和View实现控制功能。目前遇到的问题是：每次点击View中的按钮修改硬件参数时，都会重新创建Model实例并重新连接硬件。
补充说明：多次调用switcher.changeInput(switcher)后，硬件因重复连接开始拒绝请求，请问能否在View中复用已连接的单一Model实例？

Model代码 #

private IBMDSwitcher switcher;
private IBMDSwitcherMixEffectBlock me0;
public int camera { get; set; }
public AtemSwitcher()
{
    // 连接切换器
    IBMDSwitcherDiscovery discovery = new CBMDSwitcherDiscovery();
    discovery.ConnectTo("192.168.0.10", out IBMDSwitcher switcher, out _BMDSwitcherConnectToFailure failureReason);
    this.switcher = switcher;
    me0 = this.MixEffectBlocks.First();
}

static long GetInputId(IBMDSwitcherInput input)
{
    input.GetInputId(out long id);
    return id;
}

private static IBMDSwitcherInput getSwitcherInput(AtemSwitcher sw, int cam)
{
    return sw.SwitcherInputs
                                .Where((i, ret) => {
                                    i.GetPortType(out _BMDSwitcherPortType type);
                                    return type == _BMDSwitcherPortType.bmdSwitcherPortTypeExternal;
                                })
                                .ElementAt(cam);
}

public void changeInput(AtemSwitcher sw)
{ 
    me0.SetProgramInput(GetInputId(getSwitcherInput(sw, camera)));
}

Controller代码 #

public IActionResult Atem()
{
    AtemSwitcher sw = new AtemSwitcher();
    return View("Connection", sw);
}

[HttpPost]
public IActionResult Connection(AtemSwitcher switcher)
{
    if (ModelState.IsValid)
    {
        i = 10;
        switcher.changeInput(switcher);
    }

    return View();
}

View代码 #

@model pokus222.Models.AtemSwitcher
<h1>Atem control</h1>
<div class="row">
    <div class="col-md-4">
        <form asp-action="Connection">
            <div asp-validation-summary="ModelOnly" class="text-danger"></div>
            <div class="form-group">
                <label asp-for="camera" class="control-label"></label>
                <br />
                <input asp-for="camera" class="form-control" />
                <span asp-validation-for="camera" class="text-danger"></span>
            </div>
            <div class="form-group">
                <input type="submit" value="Přepni" class="btn btn-default" />
            </div>
        </form>
    </div>
</div>

要复用单一Model实例，核心是避免每次请求都创建新的AtemSwitcher对象，可以通过以下方式实现：

1. 注册单例服务（ASP.NET Core） #

将AtemSwitcher注册为单例，确保整个应用生命周期内只有一个实例：

• 在Program.cs中添加注册代码：

builder.Services.AddSingleton<AtemSwitcher>();

• 修改Controller，通过构造函数注入获取实例：

private readonly AtemSwitcher _atemSwitcher;

public YourControllerName(AtemSwitcher atemSwitcher)
{
    _atemSwitcher = atemSwitcher;
}

public IActionResult Atem()
{
    return View("Connection", _atemSwitcher);
}

[HttpPost]
public IActionResult Connection(int camera)
{
    if (ModelState.IsValid)
    {
        _atemSwitcher.camera = camera;
        _atemSwitcher.changeInput(_atemSwitcher);
    }

    return View(_atemSwitcher);
}

2. 优化Model方法 #

changeInput方法无需传入自身实例，直接使用类内成员即可：

public void changeInput()
{ 
    me0.SetProgramInput(GetInputId(getSwitcherInput(this, camera)));
}

调用时改为_atemSwitcher.changeInput();

3. 增加连接异常处理 #

在Model构造函数中添加连接校验，避免启动失败：

public AtemSwitcher()
{
    IBMDSwitcherDiscovery discovery = new CBMDSwitcherDiscovery();
    var result = discovery.ConnectTo("192.168.0.10", out IBMDSwitcher switcher, out _BMDSwitcherConnectToFailure failureReason);
    if (result == 0 && switcher != null)
    {
        this.switcher = switcher;
        me0 = this.MixEffectBlocks.First();
    }
    else
    {
        throw new Exception($"连接ATEM失败，原因：{failureReason}");
    }
}

4. 动态重连支持（可选） #

添加重连方法，避免单例实例连接断开后无法恢复：

public bool Reconnect()
{
    switcher?.Disconnect();
    
    IBMDSwitcherDiscovery discovery = new CBMDSwitcherDiscovery();
    var result = discovery.ConnectTo("192.168.0.10", out IBMDSwitcher newSwitcher, out _BMDSwitcherConnectToFailure failureReason);
    if (result == 0 && newSwitcher != null)
    {
        switcher = newSwitcher;
        me0 = this.MixEffectBlocks.First();
        return true;
    }
    return false;
}

内容的提问来源于stack exchange，提问作者Tomáš Mejzr