CF 3.5 中的 Control.Invoke 委托

发布于 2024-12-13 12:55:24 字数 2408 浏览 1 评论 0原文

似乎每个人都注意到 CF 无法 Control.Invoke 除 EventHandler 类型之外的委托。我找到了几种方法来解决该问题并通过棘手的事件和属性捕获参数，但它仅适用于某些对象/基元。

问题是当我尝试发送 Control 时，程序在执行时抛出异常：“Control.Invoke 必须用于与在单独线程上创建的控件进行交互”，无论我检查 Control.IsInvokeRequired 并由处理程序槽跟踪Invoke 方法...见鬼，有一个片段：

    static class Program
{
    [MTAThread]
    static void Main()
    {
        Form1 frm = new Form1();
        frm.modifier = new CModifier(ref frm);
        Application.Run(frm);
    }
 }

class CModifier
{
    internal event EventHandler Modify;

    internal CModifier(ref Form1 _frm)
    { frm = _frm; }

    private Form1 frm;

    internal void Start()
    {
        Thread t = new Thread(new ThreadStart(TestMe));
        t.Start();
    }
    private void TestMe()
    {
        frm._current = new Label() { Text = "Try Me" };
        Modify(this, EventArgs.Empty);
    }

}

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

    internal CModifier modifier;
    internal Control _current;

    private void Form1_Load(object sender, EventArgs e)
    {
        modifier.Modify += new EventHandler(modifier_Modify);
        modifier.Start();
    }

    void modifier_Modify(object sender, EventArgs e)
    {
        if (this.InvokeRequired)
        {
            this.Invoke(new EventHandler(modifier_Modify));
        }
        this.panel1.Controls.Add(_current);
    }

}

我尝试了几乎所有可能的方法，但总是得到相同的结果。

我做错了什么？ ---->有一个“回报”；调用后丢失。

无论如何，我的应用程序的实际错误（上面只是一个示例）是在这个过程中：

        internal void ManageControls(RSSDecisionMaking.InterfaceBehaviour _behaviour, Control _control)
    {
        if (this.InvokeRequired)
        {
            this.Invoke((Action)delegate { ManageControls(_behaviour, _control); });
            return;
        }
        switch (_behaviour)
        {
            case RSSDecisionMaking.InterfaceBehaviour.Display:
                this.pnDisplayContainer.Controls.Clear();
                this.pnDisplayContainer.Controls.Add(_control);
                break;
            case RSSDecisionMaking.InterfaceBehaviour.Command:
                this.pnDisplayContainer.Controls.Clear();
                this.pnDisplayContainer.Controls.Add(_control);
                this.pnDisplayContainer.Controls[0].Focus();
                break;
        }
    }

主要区别在于调用内容，我从另一个线程发送一个控件。

能告诉我它有什么区别吗？为什么这不起作用？

原文

It seems like everybody have noticed CF is unable to Control.Invoke delegates other than EventHandler type. I found few ways to workaround the problem and catch the arguments trough tricky events and properties, but it works just for certain objects/primitives.

The problem is when I try to send a Control, the program throws an exception at execution time: "Control.Invoke must be used to interact with controls created on a separate thread" no matters that I checked Control.IsInvokeRequired and tracked by handler trough the Invoke method...what hell, there is the snipet:

    static class Program
{
    [MTAThread]
    static void Main()
    {
        Form1 frm = new Form1();
        frm.modifier = new CModifier(ref frm);
        Application.Run(frm);
    }
 }

class CModifier
{
    internal event EventHandler Modify;

    internal CModifier(ref Form1 _frm)
    { frm = _frm; }

    private Form1 frm;

    internal void Start()
    {
        Thread t = new Thread(new ThreadStart(TestMe));
        t.Start();
    }
    private void TestMe()
    {
        frm._current = new Label() { Text = "Try Me" };
        Modify(this, EventArgs.Empty);
    }

}

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

    internal CModifier modifier;
    internal Control _current;

    private void Form1_Load(object sender, EventArgs e)
    {
        modifier.Modify += new EventHandler(modifier_Modify);
        modifier.Start();
    }

    void modifier_Modify(object sender, EventArgs e)
    {
        if (this.InvokeRequired)
        {
            this.Invoke(new EventHandler(modifier_Modify));
        }
        this.panel1.Controls.Add(_current);
    }

}

I tried to do in almost every way possible and I always get the same result.

What am I doing wrong? ----> there is a "return;" lost after Invoke.

Anyway, te actual error at my app (above is just an example) is in this procedure:

        internal void ManageControls(RSSDecisionMaking.InterfaceBehaviour _behaviour, Control _control)
    {
        if (this.InvokeRequired)
        {
            this.Invoke((Action)delegate { ManageControls(_behaviour, _control); });
            return;
        }
        switch (_behaviour)
        {
            case RSSDecisionMaking.InterfaceBehaviour.Display:
                this.pnDisplayContainer.Controls.Clear();
                this.pnDisplayContainer.Controls.Add(_control);
                break;
            case RSSDecisionMaking.InterfaceBehaviour.Command:
                this.pnDisplayContainer.Controls.Clear();
                this.pnDisplayContainer.Controls.Add(_control);
                this.pnDisplayContainer.Controls[0].Focus();
                break;
        }
    }

The main difference is in the Invoke stuff, I'm sending a Control from another thread.

Could tell me what the difference it makes? Why this does not work?

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野生奥特曼 2024-12-20 12:55:24

问题很简单。您的 modifier_Modify 调用正确调用 Invoke，但随后它不会退出，而是继续向下并在 ifControls.Add code> 块（事实上，如果没有发生异常，Controls.Add 将被调用两次）。在 this.Invoke 调用之后的 if 块内插入一个 return。