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
[我在下面提供了控制台和wpf应用程序的示例代码。]
在创建命名的Mutex实例后，只需检查createdNew变量的值(示例如下!)。
布尔值createdNew将返回false:
如果命名为“YourApplicationNameHere”的互斥锁实例已经存在 在系统某处创建
布尔值createdNew将返回true:
如果这是第一个名为“YourApplicationNameHere”的互斥锁 系统。
控制台应用程序-示例:
static Mutex m = null;
static void Main(string[] args)
{
const string mutexName = "YourApplicationNameHere";
bool createdNew = false;
try
{
// Initializes a new instance of the Mutex class with a Boolean value that indicates
// whether the calling thread should have initial ownership of the mutex, a string that is the name of the mutex,
// and a Boolean value that, when the method returns, indicates whether the calling thread was granted initial ownership of the mutex.
using (m = new Mutex(true, mutexName, out createdNew))
{
if (!createdNew)
{
Console.WriteLine("instance is alreday running... shutting down !!!");
Console.Read();
return; // Exit the application
}
// Run your windows forms app here
Console.WriteLine("Single instance app is running!");
Console.ReadLine();
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
Console.ReadLine();
}
}
WPF-Example:
public partial class App : Application
{
static Mutex m = null;
protected override void OnStartup(StartupEventArgs e)
{
const string mutexName = "YourApplicationNameHere";
bool createdNew = false;
try
{
// Initializes a new instance of the Mutex class with a Boolean value that indicates
// whether the calling thread should have initial ownership of the mutex, a string that is the name of the mutex,
// and a Boolean value that, when the method returns, indicates whether the calling thread was granted initial ownership of the mutex.
m = new Mutex(true, mutexName, out createdNew);
if (!createdNew)
{
Current.Shutdown(); // Exit the application
}
}
catch (Exception)
{
throw;
}
base.OnStartup(e);
}
protected override void OnExit(ExitEventArgs e)
{
if (m != null)
{
m.Dispose();
}
base.OnExit(e);
}
}
其他回答
一个节省时间的c# Winforms解决方案…
Program.cs:
using System;
using System.Windows.Forms;
// needs reference to Microsoft.VisualBasic
using Microsoft.VisualBasic.ApplicationServices;
namespace YourNamespace
{
public class SingleInstanceController : WindowsFormsApplicationBase
{
public SingleInstanceController()
{
this.IsSingleInstance = true;
}
protected override void OnStartupNextInstance(StartupNextInstanceEventArgs e)
{
e.BringToForeground = true;
base.OnStartupNextInstance(e);
}
protected override void OnCreateMainForm()
{
this.MainForm = new Form1();
}
}
static class Program
{
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
string[] args = Environment.GetCommandLineArgs();
SingleInstanceController controller = new SingleInstanceController();
controller.Run(args);
}
}
}
[我在下面提供了控制台和wpf应用程序的示例代码。]
在创建命名的Mutex实例后，只需检查createdNew变量的值(示例如下!)。
布尔值createdNew将返回false:
如果命名为“YourApplicationNameHere”的互斥锁实例已经存在 在系统某处创建
布尔值createdNew将返回true:
如果这是第一个名为“YourApplicationNameHere”的互斥锁 系统。
控制台应用程序-示例:
static Mutex m = null;
static void Main(string[] args)
{
const string mutexName = "YourApplicationNameHere";
bool createdNew = false;
try
{
// Initializes a new instance of the Mutex class with a Boolean value that indicates
// whether the calling thread should have initial ownership of the mutex, a string that is the name of the mutex,
// and a Boolean value that, when the method returns, indicates whether the calling thread was granted initial ownership of the mutex.
using (m = new Mutex(true, mutexName, out createdNew))
{
if (!createdNew)
{
Console.WriteLine("instance is alreday running... shutting down !!!");
Console.Read();
return; // Exit the application
}
// Run your windows forms app here
Console.WriteLine("Single instance app is running!");
Console.ReadLine();
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
Console.ReadLine();
}
}
WPF-Example:
public partial class App : Application
{
static Mutex m = null;
protected override void OnStartup(StartupEventArgs e)
{
const string mutexName = "YourApplicationNameHere";
bool createdNew = false;
try
{
// Initializes a new instance of the Mutex class with a Boolean value that indicates
// whether the calling thread should have initial ownership of the mutex, a string that is the name of the mutex,
// and a Boolean value that, when the method returns, indicates whether the calling thread was granted initial ownership of the mutex.
m = new Mutex(true, mutexName, out createdNew);
if (!createdNew)
{
Current.Shutdown(); // Exit the application
}
}
catch (Exception)
{
throw;
}
base.OnStartup(e);
}
protected override void OnExit(ExitEventArgs e)
{
if (m != null)
{
m.Dispose();
}
base.OnExit(e);
}
}
通常，这是我用于单实例Windows窗体应用程序的代码:
[STAThread]
public static void Main()
{
String assemblyName = Assembly.GetExecutingAssembly().GetName().Name;
using (Mutex mutex = new Mutex(false, assemblyName))
{
if (!mutex.WaitOne(0, false))
{
Boolean shownProcess = false;
Process currentProcess = Process.GetCurrentProcess();
foreach (Process process in Process.GetProcessesByName(currentProcess.ProcessName))
{
if (!process.Id.Equals(currentProcess.Id) && process.MainModule.FileName.Equals(currentProcess.MainModule.FileName) && !process.MainWindowHandle.Equals(IntPtr.Zero))
{
IntPtr windowHandle = process.MainWindowHandle;
if (NativeMethods.IsIconic(windowHandle))
NativeMethods.ShowWindow(windowHandle, ShowWindowCommand.Restore);
NativeMethods.SetForegroundWindow(windowHandle);
shownProcess = true;
}
}
if (!shownProcess)
MessageBox.Show(String.Format(CultureInfo.CurrentCulture, "An instance of {0} is already running!", assemblyName), assemblyName, MessageBoxButtons.OK, MessageBoxIcon.Asterisk, MessageBoxDefaultButton.Button1, (MessageBoxOptions)0);
}
else
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form());
}
}
}
本地组件的位置:
[DllImport("User32.dll", CharSet = CharSet.Unicode, ExactSpelling = true, SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
internal static extern Boolean IsIconic([In] IntPtr windowHandle);
[DllImport("User32.dll", CharSet = CharSet.Unicode, ExactSpelling = true, SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
internal static extern Boolean SetForegroundWindow([In] IntPtr windowHandle);
[DllImport("User32.dll", CharSet = CharSet.Unicode, ExactSpelling = true, SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
internal static extern Boolean ShowWindow([In] IntPtr windowHandle, [In] ShowWindowCommand command);
public enum ShowWindowCommand : int
{
Hide = 0x0,
ShowNormal = 0x1,
ShowMinimized = 0x2,
ShowMaximized = 0x3,
ShowNormalNotActive = 0x4,
Minimize = 0x6,
ShowMinimizedNotActive = 0x7,
ShowCurrentNotActive = 0x8,
Restore = 0x9,
ShowDefault = 0xA,
ForceMinimize = 0xB
}
永远不要使用命名互斥来实现单实例应用程序(至少在生产代码中不要这样做)。恶意代码可以很容易地DoS(拒绝服务)你的屁股…
更新2017-01-25。在尝试了一些东西之后，我决定使用VisualBasic.dll，它更容易，工作效果更好(至少对我来说)。我让我之前的答案只是作为参考…
只是作为参考，这是我如何不传递参数(我找不到任何理由这样做…我指的是带有参数的单个应用程序，这些参数可以从一个实例传递到另一个实例)。 如果需要文件关联，那么应用程序应该(根据用户的标准期望)为每个文档实例化。如果你必须传递args到现有的应用程序，我想我会使用vb dll。
不传递参数(只是单实例应用程序)，我更喜欢不注册一个新的窗口消息，不覆盖Matt Davis解决方案中定义的消息循环。虽然添加一个VisualBasic dll不是一个大问题，但我不喜欢添加一个新的引用只是做单个实例应用程序。此外，我更喜欢用Main实例化一个新类，而不是调用Shutdown from app. startup重写以确保尽快退出。
希望大家都喜欢……或者会启发一点:-)
项目启动类应该设置为“SingleInstanceApp”。
public class SingleInstanceApp
{
[STAThread]
public static void Main(string[] args)
{
Mutex _mutexSingleInstance = new Mutex(true, "MonitorMeSingleInstance");
if (_mutexSingleInstance.WaitOne(TimeSpan.Zero, true))
{
try
{
var app = new App();
app.InitializeComponent();
app.Run();
}
finally
{
_mutexSingleInstance.ReleaseMutex();
_mutexSingleInstance.Close();
}
}
else
{
MessageBox.Show("One instance is already running.");
var processes = Process.GetProcessesByName(Assembly.GetEntryAssembly().GetName().Name);
{
if (processes.Length > 1)
{
foreach (var process in processes)
{
if (process.Id != Process.GetCurrentProcess().Id)
{
WindowHelper.SetForegroundWindow(process.MainWindowHandle);
}
}
}
}
}
}
}
WindowHelper:
using System;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Interop;
using System.Windows.Threading;
namespace HQ.Util.Unmanaged
{
public class WindowHelper
{
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool SetForegroundWindow(IntPtr hWnd);
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