C# 如何在WPF中使用ISynchronizeInvoke接口？

我有一个这样的组件，无法更改：

public sealed class UFScannerManager
{
    public UFScannerManager(ISynchronizeInvoke synInvoke);
    public ScannerList Scanners { get; }
    public event UFS_SCANNER_PROC ScannerEvent;

    public UFS_STATUS Init();
    public UFS_STATUS Uninit();
    public UFS_STATUS Update();

    [DefaultMember("Item")]
    public sealed class ScannerList
    {
        public ScannerList(UFScannerManager Owner);

        public UFScanner this[int Index] { get; }
        public UFScanner this[string ScannerID] { get; }
        public UFScanner this[IntPtr ScannerHandle] { get; }

        public int Count { get; }
    }
}

我想创建如下组件的实例：

UFScannerManager（this）

，但在WPF中，我不能将pass

this

作为参数调用。这里的

this

表示当前窗口窗体对象，构造函数需要一个

ISynchronizeInvoke sysInvoke

参数。因此，当传递

此

时，扫描仪可以在Windows窗体应用程序中正确初始化。无需担心

ISynchronizeInvoke

接口

UFS_STATUS ufs_res;
UFScannerManager ScannerManager;
int nScannerNumber;
ScannerManager = new UFScannerManager(this);
ufs_res = ScannerManager.Init();
nScannerNumber = ScannerManager.Scanners.Count;

但是，此代码在WPF中不起作用。问题是这条线。它不喜欢的位是

此

ScannerManager = new UFScannerManager(this);

当我尝试构建时，我得到一个错误：

参数1:无法从“win_myapp”转换为“System.ComponentModel.ISynchronizeInvoke”

---

WPF不像

System.Windows.Forms.Form

类那样提供

ISynchronizeInvoke

实现。所以你需要创建一个

幸运的是，WPF的

Dispatcher

类提供了实现该功能所需的所有方法。您只需为

调度程序

和

调度程序操作

创建包装器/适配器

我可以告诉你怎么做。请注意，此代码不应“按原样”在生产环境中使用，因为它简化了，并且缺少异常处理

class DispatcherSynchronizeInvoke : ISynchronizeInvoke
{
    private readonly Dispatcher dispatcher;

    public DispatcherSynchronizeInvoke(Dispatcher dispatcher)
    {
        this.dispatcher = dispatcher;
    }

    public IAsyncResult BeginInvoke(Delegate method, object[] args)
    {
        // Obtaining a DispatcherOperation instance
        // and wrapping it with our proxy class
        return new DispatcherAsyncResult(
            this.dispatcher.BeginInvoke(method, DispatcherPriority.Normal, args));
    }

    public object EndInvoke(IAsyncResult result)
    {
        DispatcherAsyncResult dispatcherResult = result as DispatcherAsyncResult;
        dispatcherResult.Operation.Wait();
        return dispatcherResult.Operation.Result;
    }

    public object Invoke(Delegate method, object[] args)
    {
        return dispatcher.Invoke(method, DispatcherPriority.Normal, args);
    }

    public bool InvokeRequired => !this.dispatcher.CheckAccess();

    // We also could use the DispatcherOperation.Task directly
    private class DispatcherAsyncResult : IAsyncResult
    {      
        private readonly IAsyncResult result;

        public DispatcherAsyncResult(DispatcherOperation operation)
        {
            this.Operation = operation;
            this.result = operation.Task;
        }

        public DispatcherOperation Operation { get; }

        public bool IsCompleted => this.result.IsCompleted;
        public WaitHandle AsyncWaitHandle => this.result.AsyncWaitHandle;
        public object AsyncState => this.result.AsyncState;
        public bool CompletedSynchronously => this.result.CompletedSynchronously;
    }
}

使用此自定义

ISynchronizeInvoke

实现，您可以实例化您的类：

// Assuming you're calling this inside of a DispatcherObject, e.g. a Window
new UFScannerManager(new DispatcherSynchronizeInvoke(this.Dispatcher));

---

接口的优点是可以编写任意类来实现它。接口的方法很容易映射到WPF调度程序：Invoke=>Invoke，BeginInvoke=>BeginInvoke，EndInvoke=>dispatcherooperation.Wait（），InvokeRequired=>CheckAccess。