【Visual Studio Visual Csharp】Mutex

 using System;

using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows.Forms; using System.Threading; namespace mutexC { public partial class Form1 : Form { public Form1() { InitializeComponent(); if (!IsSingleInstance()) { label1.Text = "There are more instance!"; } else { label1.Text = "Only one instance!" ; } // Put label in center label1.Location = new Point(this.Size.Width / 2 - this.label1.Width / 2, this.Size.Height / 2 - this.label1.Height); } // Declare Mutex object public Mutex mutex; public bool IsSingleInstance() { try { // Open existing mutex Mutex.OpenExisting("Mutex"); } catch { // Run new instance if app don't exist mutex = new Mutex(true, "Mutex"); // App start normally return true; } // Return false is app is already opened return false; } private void Form1_Load(object sender, EventArgs e) { // Keep label on center label1.Location = new Point(this.Size.Width / 2 - this.label1.Width / 2, this.Size.Height / 2 - this.label1.Height); } } }