为 WMI 创建异步选择并等待它们完成

Question

我阅读了很多关于异步方法的帖子，但仍然......我对此有点困惑。所以也许有人可以帮助我处理我的案子。现在我的代码没有抛出任何错误，但我知道我的代码不好，因为我使用 async void 并且我不能等待我的所有任务完成。

那么，有人可以帮我编辑这段代码吗：

在我的表单类中，我创建了关系：

Relation rel = new Relation(cb_MachineToConnect.Text);

在关系类中：

public Relation(string machineAddress)
    {
        isAsctive = true;
        idCount++;
        relationID = idCount;

        machine = new Machine(machineAddress);
        //I'm using WMI for gettig data from remote machine
        scope = new ManagementScope(string.Format("\\\\{0}\\root\\cimv2", machineAddress));
        scope.Options.Timeout = TimeSpan.FromSeconds(timeOut);

        //In this method, I need run async part of code - WMI selects
        LoadMachineData();
    }

LoadMachineData 方法代码：

    private async void LoadMachineData()
    {
        try
        {
            scope.Connect();

            try
            {
                //List<Task> taskList = new List<Task>();
                foreach (KeyValuePair<SelectQueryName, SelectQuery> select in SelectQueryes)
                {
                    //And this is it.. I need to run this methods async for better performance. SelectFromWMI is in Relation class and SetWMIproiperties is in Machine class
                    await Task.Run(() => machine.SetWMIProperties(select.Key, SelectFromWMI(select.Value, scope)));
                    //taskList.Add(t);
                    //machine.SetWMIProperties(select.Key, SelectFromWMI(select.Value, scope));
                }
                //I also want to wait for all created Tasks completion, but with this code it is not possible
                //Task.WaitAll(taskList.ToArray());
            }
            catch (Exception ex)
            {
                EventNotifier.LogOnScreen(string.Format("{0}, viz: {1}", ErrorList.GetEIbyID(15).definition, ex.Message));
                EventNotifier.Log(ex, ErrorList.GetEIbyID(15));
            }
        }
        catch (Exception ex)
        {
            EventNotifier.LogOnScreen(string.Format("{0}, viz: {1}", ErrorList.GetEIbyID(16).definition, ex.Message));
            EventNotifier.Log(ex, ErrorList.GetEIbyID(17));
        }
    }

SetWMIProperties(...) 在 Machine 类中：

    public void SetWMIProperties(SelectQueryName queryName, List<Dictionary<string, string>> propertiesData)
    {
        foreach (Dictionary<string, string> result in propertiesData)
        {
            switch (queryName)
            {
                case SelectQueryName.DiskModel:

                    disks.Add(result["Model"]);
                    break;

                case SelectQueryName.Drives:

                    drives.Add(new Drive { Name = result["Name"], FreeSpace = Convert.ToInt64(result["FreeSpace"]), Size = Convert.ToInt64(result["Size"]) });
                    break;

                case SelectQueryName.OS:

                    operatingSystem = new OS { BuildNumber = result["BuildNumber"], ProductName = result["Caption"], BitVersion = (result["OSArchitecture"].Contains(((int)OSBitVersion.Win32).ToString())) ? OSBitVersion.Win32 : OSBitVersion.Win64 };
                    break;

                case SelectQueryName.Processor:

                    processor = result["Name"];
                    break;

                case SelectQueryName.RAM:

                    ram = new RAM { TotalVisibleMemorySize = Convert.ToInt64(result["TotalVisibleMemorySize"]), FreePhysicalMemory = Convert.ToInt64(result["FreePhysicalMemory"]) };
                    break;
            }
        }
    }

还有 Relation 类中的 WMI select 方法（其实这个方法应该是真正异步的，因为 WMI select 有时会很慢）：

    private static List<Dictionary<string, string>> SelectFromWMI(SelectQuery select, ManagementScope wmiScope)
    {
        List<Dictionary<string, string>> result = new List<Dictionary<string, string>>();

        ManagementObjectSearcher searcher = new ManagementObjectSearcher(wmiScope, select);
        ManagementObjectCollection objectCollection = searcher.Get();

        foreach (ManagementObject managementObject in objectCollection)
        {
            result.Add(new Dictionary<string, string>());
            foreach (PropertyData property in managementObject.Properties)
            {
                result.Last().Add(property.Name, property.Value.ToString());
            }
        }

        return result;
    }

Answer 1

要等待您的所有任务，您可以使用Task.WhenAll()：

private async void LoadMachineData()
{
    try
    {
        scope.Connect();

        try
        {
            var tasks = new List<Task>();
            foreach (KeyValuePair<SelectQueryName, SelectQuery> select in SelectQueryes)
            {
                tasks.Add(Task.Run(() => machine.SetWMIProperties(select.Key, SelectFromWMI(select.Value, scope))));
            }

            await Task.WhenAll(tasks);
        }
        catch (Exception ex)
        {
            EventNotifier.LogOnScreen(string.Format("{0}, viz: {1}", ErrorList.GetEIbyID(15).definition, ex.Message));
            EventNotifier.Log(ex, ErrorList.GetEIbyID(15));
        }
    }
    catch (Exception ex)
    {
        EventNotifier.LogOnScreen(string.Format("{0}, viz: {1}", ErrorList.GetEIbyID(16).definition, ex.Message));
        EventNotifier.Log(ex, ErrorList.GetEIbyID(17));
    }
}

要等待LoadMachineData() 完成，您可以将其签名更改为async Task 并调用LoadMachineData().Wait()。这是你需要的吗？