在线时间:8:00-16:00
迪恩网络APP
随时随地掌握行业动态
扫描二维码
关注迪恩网络微信公众号
对于存在窗体的WPF程序(或者说,起码在任务栏上有个图标,即ShowInTaskbar = true),互相传递消息是很容易的。 步骤: 1,寻找窗体的句柄 2,运用windows API: SendMessage或PostMessage 3,目标窗体收到消息
这里的代码,展示了一个APP不希望多开所以在启动时检查是否存在一个已经运行的进程。如果进程已经存在,则给对方发送消息并结束自身。 1.判断/获取已经运行的实例 /// <summary> /// 获取当前exe文件的是否已经在电脑上运行了一个实例,如果是,则返回那个实例的Process;如果否,就返回null; /// 如果有窗体,可以通过process.MainWindowHandle获取窗体的句柄,如果没窗体(ShowInTaskbar = false),则句柄为空 /// </summary> public static Process GetCurrentExeProcess() { Process targetProcess = null; Process currentProcess = Process.GetCurrentProcess(); string exeName = string.Format("{0}.exe", currentProcess.ProcessName); //PTZ.Tracer.AppLog.Info("$$$$$Get Current Process Successfully, current process exe: {0}", exeName); try { Process[] aryProcess = Process.GetProcessesByName(currentProcess.ProcessName); //PTZ.Tracer.AppLog.Info("$$$$$Get aryProcess Successfully, aryProcess count: {0}", aryProcess.Count()); foreach (Process process in aryProcess) { if (process.Id != currentProcess.Id && process.ProcessName == currentProcess.ProcessName) { targetProcess = process; //PTZ.Tracer.AppLog.Info("$$$$$Get MainWindowHandle Successfully, hWnd: {0}", hWnd); break; } } } catch (System.PlatformNotSupportedException pEx) { //PTZ.Tracer.AppLog.Error("$$$$$GetCurrentWindowsInstanceHandle exception:", pEx); } catch (System.InvalidOperationException iEx) { //PTZ.Tracer.AppLog.Error("$$$$$GetCurrentWindowsInstanceHandle exception:", iEx); } catch (System.ComponentModel.Win32Exception win32Ex) { //PTZ.Tracer.AppLog.Error("$$$$$GetCurrentWindowsInstanceHandle exception:", win32Ex); } return targetProcess; } 但是这个方法在某些奇怪权限设置的电脑上会遭遇UnauthorizedException,所以,如果只是想获取窗体句柄的话,还可以将上述方法的Try & Catch部分换成下面的代码: try { string wmiQueryString = string.Format("SELECT ProcessId, Handle,ExecutablePath,Name FROM Win32_Process WHERE ProcessId != {0} AND Name = '{1}'", currentProcess.Id, exeName); using (var searcher = new ManagementObjectSearcher(wmiQueryString)) { using (var results = searcher.Get()) { ManagementObject mo = results.Cast<ManagementObject>().FirstOrDefault(); if (mo != null) { string s = (string)mo["ExecutablePath"]; string handleStr = (string)mo["Handle"]; string sss = (string)mo["Name"]; Tracing.Trace.Information("¥*¥ManagementObjectSearcher, name: {0} Handle: {1} Path: {2}", sss, handleStr, s); int handle = int.Parse(handleStr); Process p = Process.GetProcessById(handle); hWnd = p.MainWindowHandle; isRunExist = true; Tracing.Trace.Information("¥*¥ManagementObjectSearcher, hWnd: {0}", hWnd); } } } } catch (Exception e) { Tracing.Trace.Error("ManagementObjectSearcher exception:", e); } 2.注册WindowsAPI #region Dll Imports [DllImport("user32.dll")] static extern IntPtr PostMessage(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam); public const uint WM_APP = 0x9112;////0x8001~0xBFFF,随意#endregion Dll Imports 3.修改App.OnStartup方法 当程序启动,就需要检测实例。如已有实例运行,则发送消息;如没有,则继续正常运行。所以我们需要修改Appxaml.cs的OnStartup方法: protected override void OnStartup(StartupEventArgs e) { base.OnStartup(e); Process targetProcess = SingleExeHelper.GetCurrentExeProcess(); if (targetProcess!=null)//Software has been running... { //currentHandle通过targetProcess.MainWindowHandle得到 PostMessage(currentHandle,WM_APP, IntPtr.Zero, IntPtr.Zero); Software has been running, close this } else { //do nothing } }
4.主窗体监听消息: protected override void OnSourceInitialized(EventArgs e) { base.OnSourceInitialized(e); ((HwndSource)PresentationSource.FromVisual(this)).AddHook(myHook); //HwndSource source = HwndSource.FromHwnd(new WindowInteropHelper(this).Handle); //source.AddHook(new HwndSourceHook(myHook)); } private IntPtr myHook(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled) { int m = (int)App.WM_APP; if (msg == m) { System.Windows.MessageBox.Show("haha"); } return IntPtr.Zero; }
|
请发表评论