在继续之前等待结果,并且不阻塞UI[重复]

我有一个 TextBox 用一个 TextChanged

我看到的基本上有2个“选项”/场景。

1. 在自定义事件中,在继续事件之前,以某种方式等待dll调用完成,同时保持UI空闲。这似乎是我未经训练的多线程自我提出的最简单的想法,但从概念上讲,它也给我带来了危险:考虑到自定义事件本身(从 事件 )在UI线程上?
2. 使用将整个自定义事件抛出到自己的线程中 Task.Run() InvokeRequired ,但如果有更正确的方法,我宁愿采用这种方法。

我用上面的选项2制作了一个更短(尽管是人为的)的示例项目,它基本上显示了我想要的东西:

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();

        comboBox1.Items.Add("Select One...");
        comboBox1.Items.Add("Item 1");
        comboBox1.Items.Add("Item 2");

        Value = 0;
    }

    public string SetMessage
    {
        set
        {
            if (lblInfo.InvokeRequired)
                lblInfo.BeginInvoke((MethodInvoker)delegate () { lblInfo.Text = Important ? value + "!" : value; });
            else
                lblInfo.Text = Important ? value + "!" : value;
        }
    }

    public bool Important
    {
        get
        {
            return chkImportant.Checked;
        }
        set
        {
            if (chkImportant.InvokeRequired)
                chkImportant.BeginInvoke((MethodInvoker) delegate() { chkImportant.Checked = value; });
            else
                chkImportant.Checked = value;
        }
    }

    public SomeValue Value
    {
        get
        {
            if (comboBox1.InvokeRequired)
            {
                SomeValue v = (SomeValue)comboBox1.Invoke(new Func<SomeValue>(() => SomeValue.Bar));
                return v;
            }
            else
            {
                switch (comboBox1.SelectedIndex)
                {
                    case 1:
                        return SomeValue.Foo;
                    case 2:
                        return SomeValue.Bar;
                    default:
                        return SomeValue.Nothing;
                }
            }
        }
        set
        {
            if (comboBox1.InvokeRequired)
            {
                comboBox1.BeginInvoke((MethodInvoker)delegate ()
                {
                   switch (value)
                   {
                       case SomeValue.Nothing:
                           comboBox1.SelectedIndex = 0;
                           break;
                       case SomeValue.Foo:
                           comboBox1.SelectedIndex = 1;
                           break;
                       case SomeValue.Bar:
                           comboBox1.SelectedIndex = 2;
                           break;
                   }
                });
            }
            else
            {
                switch (value)
                {
                    case SomeValue.Nothing:
                        comboBox1.SelectedIndex = 0;
                        break;
                    case SomeValue.Foo:
                        comboBox1.SelectedIndex = 1;
                        break;
                    case SomeValue.Bar:
                        comboBox1.SelectedIndex = 2;
                        break;
                }
            }
        }
    }

    private void CustomEvent(object sender, EventArgs e)
    {
        if (!Important)
            Important = true;

        SetMessage = "Doing some stuff";

        if (Value == SomeValue.Foo)
            Debug.WriteLine("Foo selected");

        //I don't want to continue until a result is returned, 
        //but I don't want to block UI either.
        if (ReturnsTrueEventually())
        {

            Debug.WriteLine("True!");
        }

        Important = false;
        SetMessage = "Finished.";
    }

    public bool ReturnsTrueEventually()
    {
        //Simulates some long running method call in a dll.
        //In reality, I would interpret an integer and return 
        //an appropriate T/F value based on it.
        Thread.Sleep(5000);

        return true;
    }

    private void textBox1_TextChanged(object sender, EventArgs e)
    {
        //Do I *need* to multithread the whole thing?
        Task.Run(() => CustomEvent(this, new EventArgs()));
    }
}

public enum SomeValue
{
    Nothing = 0,
    Foo = 100,
    Bar = 200
}

笔记 :我没有要求对我的选项2代码进行代码审查。相反,我要问的是,选项2是否有必要完成,因为该选项会导致我更改相当大的代码部分,因为其中只有一个方法可以支撑整个过程。

我还意识到我可以简化这些属性中的一些代码,以防止复制。为了给自己演示和调试,我现在暂缓。

下面是我与选项1相关的内容(省略了重复代码和没有调用的getter/setter):

private async void CustomEvent(object sender, EventArgs e)
{
    if (!Important)
        Important = true;

    SetMessage = "Doing some stuff";

    if (Value == SomeValue.Foo)
        Debug.WriteLine("Foo selected");

    //I don't want to continue until a result is returned, 
    //but I don't want to block UI either.
    if (await ReturnsTrueEventually())
    {

        Debug.WriteLine("True!");
    }

    Important = false;
    SetMessage = "Finished.";
}

public async Task<bool> ReturnsTrueEventually()
{
    //Simulates some long running method call in a dll.
    //In reality, I would interpret an integer and 
    //return an appropriate T/F value based on it.
    Thread.Sleep(5000);

    return true;
}