我創(chuàng)建了一個(gè)旨在運(yùn)行單個(gè)實(shí)例的程序，其中包含一個(gè)隱藏的表單，直到收到廣播消息。錯(cuò)誤是除非在創(chuàng)建時(shí)顯示表單，否則不會(huì)收到消息。為什么要在這個(gè)階段展示表格？我舉了一個(gè)例子。程序的第一個(gè)運(yùn)行實(shí)例創(chuàng)建表單，其他實(shí)例向它廣播消息。using System;using System.Runtime.InteropServices;using System.Threading;using System.Windows.Forms;namespace HiddenProgram{public class Program : ApplicationContext{ [DllImport("user32")] static extern bool PostMessage(IntPtr hwnd, int msg, IntPtr wparam, IntPtr lparam); [DllImport("user32")] static extern int RegisterWindowMessage(string message); const int HWND_BROADCAST = 0xffff; public static readonly int WM_SHOWME = Program.RegisterWindowMessage("com.holroyd.Gateway.Show"); public static Program Instance; static Mutex mutex = new Mutex(true, "{9BFB3652-CCE9-42A2-8CDE-BBC40A0F5213}"); MyForm form; [STAThread] static void Main() { Application.EnableVisualStyles(); Application.SetCompatibleTextRenderingDefault(false); if (!mutex.WaitOne(TimeSpan.Zero, true)) { // Show the single instance window PostMessage( (IntPtr)HWND_BROADCAST, WM_SHOWME, IntPtr.Zero, IntPtr.Zero); } else { // Create the hidden window Instance = new Program(); Application.Run(Instance); mutex.ReleaseMutex(); } } Program() { form = new MyForm(); form.FormClosing += form_FormClosing; // One of the following two seem necessary to get the broadcast message form.Show(); //MainForm = form; } void form_FormClosing(object sender, FormClosingEventArgs e) { ExitThread(); }}public class MyForm : Form{ protected override void WndProc(ref Message m) { if (m.Msg == Program.WM_SHOWME) Visible = !Visible; else base.WndProc(ref m); }}
1 回答
SMILET
TA貢獻(xiàn)1796條經(jīng)驗(yàn) 獲得超4個(gè)贊
要?jiǎng)?chuàng)建一個(gè)在收到廣播消息之前保持隱藏的窗體，從窗體的構(gòu)造函數(shù)調(diào)用 CreateHandle()，以創(chuàng)建底層窗口，以便接收來自程序的其他實(shí)例的廣播消息。
using System;
using System.Runtime.InteropServices;
using System.Threading;
using System.Windows.Forms;
namespace HiddenProgram
{
public class Program : ApplicationContext
{
[DllImport("user32")]
static extern bool PostMessage(IntPtr hwnd, int msg, IntPtr wparam, IntPtr lparam);
[DllImport("user32")]
static extern int RegisterWindowMessage(string message);
const int HWND_BROADCAST = 0xffff;
public static readonly int WM_SHOWME = Program.RegisterWindowMessage("com.holroyd.Gateway.Show");
static Mutex mutex = new Mutex(true, "{9BFB3652-CCE9-42A2-8CDE-BBC40A0F5213}");
MyForm form;
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
if (!mutex.WaitOne(TimeSpan.Zero, true))
{
// Show the single instance window
PostMessage(
(IntPtr)HWND_BROADCAST,
WM_SHOWME,
IntPtr.Zero,
IntPtr.Zero);
}
else
{
// Create the hidden window
Application.Run(new Program());
mutex.ReleaseMutex();
}
}
Program()
{
form = new MyForm();
form.FormClosing += form_FormClosing;
}
void form_FormClosing(object sender, FormClosingEventArgs e)
{
ExitThread();
}
}
public class MyForm : Form
{
public MyForm()
{
CreateHandle();
}
protected override void WndProc(ref Message m)
{
if (m.Msg == Program.WM_SHOWME)
Visible = !Visible;
else
base.WndProc(ref m);
}
}
}
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