本文以实例描述了C#实现让窗体永远在窗体最前面显示的方法,具体步骤以下:html
一、新建一个窗体程序,添加一个Timer以及设置它可用并绑定事件。前端
二、设置窗体的TopMost属性为Trueapp
三、而后设置代码以下便可实现.函数
using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Text; using System.Windows.Forms;namespace jiyi { public partial class Form1 : Form {public Form1() { InitializeComponent(); } private void Form1_Load(object sender, EventArgs e) { } private void timer1_Tick(object sender, EventArgs e) { this.TopMost = false; this.BringToFront(); this.TopMost = true; } } }
出处:https://www.jb51.net/article/52401.htm this
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防止程序运行多个实例的方法有多种,如:经过使用互斥量和进程名等.而我想要实现的是:在程序运行多个实例时激活的是第一个实例,使其得到焦点,并在前端显示..net 主要用到两个API 函数:线程
代码以下: |
using System.Runtime.InteropServices; using System.Diagnostics; using System.Reflection; //***************************************************** static class Program { /// <summary> /// 该函数设置由不一样线程产生的窗口的显示状态。 /// </summary> /// <param name="hWnd">窗口句柄</param> /// <param name="cmdShow">指定窗口如何显示。查看容许值列表,请查阅ShowWlndow函数的说明部分。</param> /// <returns>若是函数原来可见,返回值为非零;若是函数原来被隐藏,返回值为零。</returns> [DllImport("User32.dll")] private static extern bool ShowWindowAsync(IntPtr hWnd, int cmdShow); /// <summary> /// 该函数将建立指定窗口的线程设置到前台,而且激活该窗口。键盘输入转向该窗口,并为用户改各类可视的记号。系统给建立前台窗口的线程分配的权限稍高于其余线程。 /// </summary> /// <param name="hWnd">将被激活并被调入前台的窗口句柄。</param> /// <returns>若是窗口设入了前台,返回值为非零;若是窗口未被设入前台,返回值为零。</returns> [DllImport("User32.dll")] private static extern bool SetForegroundWindow(IntPtr hWnd); private const int WS_SHOWNORMAL = 1; /// <summary> /// 应用程序的主入口点。 /// </summary> [STAThread] static void Main() { Application.EnableVisualStyles(); Application.SetCompatibleTextRenderingDefault(false); Process instance = RunningInstance(); if (instance == null) { Form1 frm = new Form1(); Application.Run(new Form1()); } else { HandleRunningInstance(instance); } } /// <summary> /// 获取正在运行的实例,没有运行的实例返回null; /// </summary> public static Process RunningInstance() { Process current = Process.GetCurrentProcess(); Process[] processes = Process.GetProcessesByName(current.ProcessName); foreach (Process process in processes) { if (process.Id != current.Id) { if (Assembly.GetExecutingAssembly().Location.Replace("/", "\\") == current.MainModule.FileName) { return process; } } } return null; } /// <summary> /// 显示已运行的程序。 /// </summary> public static void HandleRunningInstance(Process instance) { ShowWindowAsync(instance.MainWindowHandle, WS_SHOWNORMAL); //显示,能够注释掉 SetForegroundWindow(instance.MainWindowHandle); //放到前端 } }
//=====建立互斥体法:===== bool blnIsRunning; Mutex mutexApp = new Mutex(false, Assembly.GetExecutingAssembly().FullName, out blnIsRunning); if (!blnIsRunning) { MessageBox.Show("程序已经运行!", "提示", MessageBoxButtons.OK, MessageBoxIcon.Exclamation); return; } //保证同时只有一个客户端在运行 System.Threading.Mutex mutexMyapplication = new System.Threading.Mutex(false, "OnePorcess.exe"); if (!mutexMyapplication.WaitOne(100, false)) { MessageBox.Show("程序" + Application.ProductName + "已经运行!", Application.ProductName, MessageBoxButtons.OK, MessageBoxIcon.Error); return; } //=====判断进程法:(修改程序名字后依然能执行)===== Process current = Process.GetCurrentProcess(); Process[] processes = Process.GetProcessesByName(current.ProcessName); foreach (Process process in processes) { if (process.Id != current.Id) { if (process.MainModule.FileName == current.MainModule.FileName) { MessageBox.Show("程序已经运行!", Application.ProductName, MessageBoxButtons.OK, MessageBoxIcon.Exclamation); return; } } }
出处:http://www.soaspx.com/dotnet/csharp/csharp_20130319_10168.htmlorm