form1.cs

C#150例

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Threading;
using System.Runtime.InteropServices;

namespace Example104_使程序只能够运行一个
{
	/// <summary>
	/// Form1 的摘要说明。
	/// </summary>
	public class Form1 : System.Windows.Forms.Form
	{
		/// <summary>
		/// 必需的设计器变量。
		/// </summary>
		private System.ComponentModel.Container components = null;

		public Form1()
		{
			//
			// Windows 窗体设计器支持所必需的
			//
			InitializeComponent();

			//
			// TODO: 在 InitializeComponent 调用后添加任何构造函数代码
			//
		}

		/// <summary>
		/// 清理所有正在使用的资源。
		/// </summary>
		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if (components != null) 
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}

		#region Windows Form Designer generated code
		/// <summary>
		/// 设计器支持所需的方法 - 不要使用代码编辑器修改
		/// 此方法的内容。
		/// </summary>
		private void InitializeComponent()
		{
			// 
			// Form1
			// 
			this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
			this.ClientSize = new System.Drawing.Size(272, 189);
			this.Name = "Form1";
			this.Text = "Form1";

		}
		#endregion

		/// <summary>
		/// 应用程序的主入口点。
		/// </summary>

		[StructLayout( LayoutKind.Sequential)]
		public class SECURITY_ATTRIBUTES 
		{
			public int nLength; 
			public int lpSecurityDescriptor; 
			public int bInheritHandle; 
		}

		[System.Runtime.InteropServices.DllImport("kernel32")]
		private static extern int GetLastError();
		[System.Runtime.InteropServices.DllImport("kernel32")]
		private static extern IntPtr CreateMutex(SECURITY_ATTRIBUTES lpMutexAttributes,bool bInitialOwner,string lpName);
		[System.Runtime.InteropServices.DllImport("kernel32")]
		private static extern int ReleaseMutex(IntPtr hMutex);
		const int ERROR_ALREADY_EXISTS = 0183;

		[STAThread]
		static void Main() 
		{
			IntPtr hMutex;
			hMutex=CreateMutex(null,false,"test");
			if (GetLastError()!=ERROR_ALREADY_EXISTS)
			{
				Application.Run(new Form1());
			}
			else
			{
				MessageBox.Show("本程序只允许同时运行一个");
				ReleaseMutex(hMutex);
			}
		}
	}
}