Question

程序已打开，并且在托盘中，重新点击程序时，不用重新运行，仅最大化托盘中的程序！

使用了ShowWindowAsync只能实现最小化的时候可以激活窗口，但是托盘状态不行，哪位高手知道，请多多指教

Answer 1

几处要修改:
一修改Program.cs:
原来为:
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
}

添加命名空间:
using System.Diagnostics;
using System.Runtime.InteropServices;
然后修改代码为:
public const int WM_PROCESSISRUNNING = 0x0400 + 101;

[DllImport("user32")]
public static extern int SendMessage(IntPtr hWnd, int Msg, int wParam, int lParam);

/// <summary>
/// 应用程序的主入口点。
/// </summary>
[STAThread]
static void Main()
{
Process pCurrent = Process.GetCurrentProcess();
Process[] pList = Process.GetProcessesByName(pCurrent.ProcessName);
if (pList.Length < 2)
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
}
else
{
SendMessage(pList[0].MainWindowHandle, WM_PROCESSISRUNNING, 0, 0);
}
}

然后到主窗体里面加入代码:
protected override void WndProc(ref Message m)
{
if (m.Msg == Program.WM_PROCESSISRUNNING)
{
this.WindowState = FormWindowState.Normal;
}
base.WndProc(ref m);
}

Answer 2

#region dll import
[DllImport("User32.dll")]
public static extern IntPtr FindWindow(string classname, string windowname);
[DllImport("User32.dll")]
public static extern IntPtr GetForegroundWindow();
[DllImport("User32.dll")]
public static extern long SetForegroundWindow(IntPtr hwnd);
[DllImport("User32.dll")]
public static extern long GetWindowText(IntPtr hwnd, string lpString, long cch);
public IntPtr formhwnd;
#endregion

public Form1()
{
//只运行一个实例
formhwnd = FindWindow(null, "From1");
if (formhwnd.ToInt32() > 0)
{
MessageBox.Show("系统已运行！查看是否最小化！", "安全", MessageBoxButtons.OK, MessageBoxIcon.Information);
SetForegroundWindow(formhwnd);
this.Close();
}
InitializeComponent();
}