在。net下使用c#和WPF(而不是Windows窗体或控制台),创建一个只能作为单个实例运行的应用程序的正确方法是什么?
我知道它与某种叫做互斥的神秘事物有关,我很少能找到有人费心停下来解释其中一个是什么。
代码还需要通知已经运行的实例,用户试图启动第二个实例,如果存在命令行参数,还可能传递任何命令行参数。
在。net下使用c#和WPF(而不是Windows窗体或控制台),创建一个只能作为单个实例运行的应用程序的正确方法是什么?
我知道它与某种叫做互斥的神秘事物有关,我很少能找到有人费心停下来解释其中一个是什么。
代码还需要通知已经运行的实例,用户试图启动第二个实例,如果存在命令行参数,还可能传递任何命令行参数。
当前回答
这是我的两分钱
static class Program
{
[STAThread]
static void Main()
{
bool createdNew;
using (new Mutex(true, "MyApp", out createdNew))
{
if (createdNew) {
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
var mainClass = new SynGesturesLogic();
Application.ApplicationExit += mainClass.tray_exit;
Application.Run();
}
else
{
var current = Process.GetCurrentProcess();
foreach (var process in Process.GetProcessesByName(current.ProcessName).Where(process => process.Id != current.Id))
{
NativeMethods.SetForegroundWindow(process.MainWindowHandle);
break;
}
}
}
}
}
其他回答
我在这里找不到一个简单的解决方案,所以我希望有人会喜欢这个:
更新2018-09-20
把这段代码放在Program.cs中:
using System.Diagnostics;
static void Main()
{
Process thisProcess = Process.GetCurrentProcess();
Process[] allProcesses = Process.GetProcessesByName(thisProcess.ProcessName);
if (allProcesses.Length > 1)
{
// Don't put a MessageBox in here because the user could spam this MessageBox.
return;
}
// Optional code. If you don't want that someone runs your ".exe" with a different name:
string exeName = AppDomain.CurrentDomain.FriendlyName;
// in debug mode, don't forget that you don't use your normal .exe name.
// Debug uses the .vshost.exe.
if (exeName != "the name of your executable.exe")
{
// You can add a MessageBox here if you want.
// To point out to users that the name got changed and maybe what the name should be or something like that^^
MessageBox.Show("The executable name should be \"the name of your executable.exe\"",
"Wrong executable name", MessageBoxButtons.OK, MessageBoxIcon.Error);
return;
}
// Following code is default code:
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new MainForm());
}
我添加了一个sendMessage方法到NativeMethods类。
显然,如果应用程序没有显示在任务栏中,postmessage方法不会工作,但是使用sendmessage方法解决了这个问题。
class NativeMethods
{
public const int HWND_BROADCAST = 0xffff;
public static readonly int WM_SHOWME = RegisterWindowMessage("WM_SHOWME");
[DllImport("user32")]
public static extern bool PostMessage(IntPtr hwnd, int msg, IntPtr wparam, IntPtr lparam);
[DllImport("user32.dll", CharSet = CharSet.Auto)]
public static extern IntPtr SendMessage(IntPtr hWnd, int Msg, IntPtr wParam, IntPtr lParam);
[DllImport("user32")]
public static extern int RegisterWindowMessage(string message);
}
但是不使用互斥,简单的回答:
System.Diagnostics;
...
string thisprocessname = Process.GetCurrentProcess().ProcessName;
if (Process.GetProcesses().Count(p => p.ProcessName == thisprocessname) > 1)
return;
把它放在Program.Main()中。 例子:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Diagnostics;
namespace Sample
{
static class Program
{
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
//simple add Diagnostics namespace, and these 3 lines below
string thisprocessname = Process.GetCurrentProcess().ProcessName;
if (Process.GetProcesses().Count(p => p.ProcessName == thisprocessname) > 1)
return;
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Sample());
}
}
}
您可以添加MessageBox。在if语句中显示并输入“应用程序已运行”。 这可能对某些人有帮助。
这是我的两分钱
static class Program
{
[STAThread]
static void Main()
{
bool createdNew;
using (new Mutex(true, "MyApp", out createdNew))
{
if (createdNew) {
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
var mainClass = new SynGesturesLogic();
Application.ApplicationExit += mainClass.tray_exit;
Application.Run();
}
else
{
var current = Process.GetCurrentProcess();
foreach (var process in Process.GetProcessesByName(current.ProcessName).Where(process => process.Id != current.Id))
{
NativeMethods.SetForegroundWindow(process.MainWindowHandle);
break;
}
}
}
}
}
这里有一个解决方案:
Protected Overrides Sub OnStartup(e As StartupEventArgs)
Const appName As String = "TestApp"
Dim createdNew As Boolean
_mutex = New Mutex(True, appName, createdNew)
If Not createdNew Then
'app is already running! Exiting the application
MessageBox.Show("Application is already running.")
Application.Current.Shutdown()
End If
MyBase.OnStartup(e)
End Sub