生成一个新线程以打开一个新窗口并从另一个线程关闭它

Question

现在我有C#代码在不同的线程中生成一个新窗口,这是有效的,但是一旦新生成的窗口打开,它就会关闭并且线程结束.我怎样才能使这个新生成的窗口可以从第一个线程关闭？

这是产卵目前如何运作的"树":

主线程 -
在主线程中使用一个函数在另一个线程中启动另一个函数来打开w窗口,导致窗口使用该线程.

基本上我只想让每个窗口都有自己的线程.并能够从第一个窗口线程控制生成的辅助窗口.

Answer 1

我打赌你正在做的是这样的:

new Thread(() => new TestForm().Show()).Start();

因为这会使窗口立即消失,就像你描述的那样.

试试这个:

 new Thread(() => new TestForm().ShowDialog()).Start();

ShowDialog旋转自己的消息泵,仅在窗口关闭时返回.

Answer 2

这只是一个简单的例子.它比我写的第一个更强大.它通过使用p/invoke消除了现有的竞争条件.

更新 Still仍有竞争条件.这个应该是完美的.

using System;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Threading;
using System.Windows.Forms;

class MainUIThreadForm : Form
{
    [STAThread]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Application.Run(new MainUIThreadForm());
    }

    private IntPtr secondThreadFormHandle;

    public MainUIThreadForm()
    {
        Text = "First UI";
        Button button;
        Controls.Add(button = new Button { Name = "Start", Text = "Start second UI thread", AutoSize = true, Location = new Point(10, 10) });
        button.Click += (s, e) =>
        {
            if (secondThreadFormHandle == IntPtr.Zero)
            {
                Form form = new Form
                {
                    Text = "Second UI",
                    Location = new Point(Right, Top),
                    StartPosition = FormStartPosition.Manual,
                };
                form.HandleCreated += SecondFormHandleCreated;
                form.HandleDestroyed += SecondFormHandleDestroyed;
                form.RunInNewThread(false);
            }
        };
        Controls.Add(button = new Button { Name = "Stop", Text = "Stop second UI thread", AutoSize = true, Location = new Point(10, 40), Enabled = false });
        button.Click += (s, e) =>
        {
            if (secondThreadFormHandle != IntPtr.Zero)
                PostMessage(secondThreadFormHandle, WM_CLOSE, IntPtr.Zero, IntPtr.Zero);
        };
    }

    void EnableStopButton(bool enabled)
    {
        if (InvokeRequired)
            BeginInvoke((Action)(() => EnableStopButton(enabled)));
        else
        {
            Control stopButton = Controls["Stop"];
            if (stopButton != null)
                stopButton.Enabled = enabled;
        }
    }

    void SecondFormHandleCreated(object sender, EventArgs e)
    {
        Control second = sender as Control;
        secondThreadFormHandle = second.Handle;
        second.HandleCreated -= SecondFormHandleCreated;
        EnableStopButton(true);
    }

    void SecondFormHandleDestroyed(object sender, EventArgs e)
    {
        Control second = sender as Control;
        secondThreadFormHandle = IntPtr.Zero;
        second.HandleDestroyed -= SecondFormHandleDestroyed;
        EnableStopButton(false);
    }

    const int WM_CLOSE = 0x0010;
    [DllImport("User32.dll")]
    extern static IntPtr PostMessage(IntPtr hWnd, int message, IntPtr wParam, IntPtr lParam);
}

internal static class FormExtensions
{
    private static void ApplicationRunProc(object state)
    {
        Application.Run(state as Form);
    }

    public static void RunInNewThread(this Form form, bool isBackground)
    {
        if (form == null)
            throw new ArgumentNullException("form");
        if (form.IsHandleCreated)
            throw new InvalidOperationException("Form is already running.");
        Thread thread = new Thread(ApplicationRunProc);
        thread.SetApartmentState(ApartmentState.STA);
        thread.IsBackground = isBackground;
        thread.Start(form);
    }
}

这是后人的第一个例子:

using System;
using System.Drawing;
using System.Threading;
using System.Windows.Forms;

class MainUIThreadForm : Form
{
    [STAThread]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Application.Run(new MainUIThreadForm());
    }

    SecondUIThreadForm secondThreadForm;
    public MainUIThreadForm()
    {
        Text = "First UI";
        Button button;
        Controls.Add(button = new Button { Text = "Start second UI thread", AutoSize = true, Location = new Point(10, 10) });
        button.Click += (s, e) =>
            {
                if (secondThreadForm == null || !secondThreadForm.IsHandleCreated)
                    secondThreadForm = SecondUIThreadForm.Create();
            };
        Controls.Add(button = new Button { Text = "Stop second UI thread", AutoSize = true, Location = new Point(10, 40) });
        button.Click += (s, e) =>
        {
            if (secondThreadForm != null && secondThreadForm.IsHandleCreated)
                secondThreadForm.Invoke((Action)(() => secondThreadForm.Close()));
        };
    }
}

class SecondUIThreadForm : Form
{
    static void Main2(object state)
    {
        Application.Run((Form)state);
    }

    public static SecondUIThreadForm Create()
    {
        SecondUIThreadForm form = new SecondUIThreadForm();
        Thread thread = new Thread(Main2);
        thread.SetApartmentState(ApartmentState.STA);
        thread.Start(form);
        return form;
    }

    public SecondUIThreadForm()
    {
        Text = "Second UI";
    }
}