WPF App.xaml.cs常用模板，包括：異常捕獲，App只能啟動一次

App.xaml.cs中的代碼每次都差不多，故特地將其整理出來直接復用：

  5 using System;
  6 using System.Configuration;
  7 using System.Diagnostics;
  8 using System.Globalization;
  9 using System.Net;
 10 using System.Net.Sockets;
 11 using System.Reflection;
 12 using System.Runtime.InteropServices;
 13 using System.Windows;
 14 
 15 namespace WpfDemo
 16 {
 17     /// <summary>
 18     /// App.xaml 的交互邏輯
 19     /// </summary>
 20     public partial class App : Application
 21     {
 22         private LoginWindow login = new LoginWindow();
 23         private ILog logger;
 24 
 25         static App()
 26         {
 27             log4net.Config.XmlConfigurator.Configure();
 28         }
 29 
 30         public App()
 31         {
 32             logger = LogManager.GetLogger(typeof(this));
 33         }
 34 
 35         System.Threading.Mutex _mutex;
 36         protected override void OnStartup(StartupEventArgs e)
 37         {
 38             Assembly assembly = Assembly.GetExecutingAssembly();
 39             string mutexName = string.Format(CultureInfo.InvariantCulture, "Local\\{{{0}}}{{{1}}}", assembly.GetType().GUID, assembly.GetName().Name);
 40             bool ret = false;
 41             _mutex = new System.Threading.Mutex(true, mutexName, out ret);
 42             if (!ret)
 43             {
 44                 this.logger.Info("已經運行程式，激活至主視窗.");
 45                 HandleRunningInstance();
 46                 Environment.Exit(0);
 47                 return;
 48             }
 49 
 50             base.OnStartup(e);
 51             this.logger.Info("App startup.");
 52             this.ShutdownMode = System.Windows.ShutdownMode.OnExplicitShutdown;
 53 
 54             AppDomain.CurrentDomain.UnhandledException += CurrentDomain_UnhandledException;
 55             this.DispatcherUnhandledException += App_DispatcherUnhandledException;
 56 
 57             this.login.Show();
 58         }
 59 
 60         void CurrentDomain_UnhandledException(object sender, UnhandledExceptionEventArgs e)
 61         {
 62             try
 63             {
 64                 var exception = e.ExceptionObject as Exception;
 65                 if (exception != null)
 66                 {
 67                     this.logger.FatalFormat("非UI線程全局異常, Message:{0}, Error: {1}", exception.Message, exception.ToString());
 68                 }
 69             }
 70             catch (Exception ex)
 71             {
 72                 this.logger.FatalFormat("非UI線程全局異常, Message:{0}, Error: {1}", ex.Message, ex.ToString());
 73             }
 74         }
 75 
 76         void App_DispatcherUnhandledException(object sender, System.Windows.Threading.DispatcherUnhandledExceptionEventArgs e)
 77         {
 78             try
 79             {
 80                 e.Handled = true;
 81                 this.logger.FatalFormat("UI線程全局異常：Meassage:{0}, Error: {1}", e.Exception.Message, e.Exception.ToString());
 82             }
 83             catch (Exception ex)
 84             {
 85                 this.logger.FatalFormat("UI線程全局異常：Meassage:{0}, Error: {1}", ex.Message, ex.ToString());
 86             }
 87         }
 88 
 89         
 90         protected override void OnExit(ExitEventArgs e)
 91         {
 92             this.logger.Info("App exit.");
 93             
 94             base.OnExit(e);
 95         }
 96 
 97         ///<summary>
 98         /// 該函數設置由不同線程產生的視窗的顯示狀態
 99         /// </summary>
100         /// <param name="hWnd">視窗句柄</param>
101         /// <param name="cmdShow">指定視窗如何顯示。查看允許值列表，請查閱ShowWlndow函數的說明部分</param>
102         /// <returns>如果函數原來可見，返回值為非零；如果函數原來被隱藏，返回值為零</returns>
103         [DllImport("User32.dll")]
104         private static extern bool ShowWindowAsync(IntPtr hWnd, int cmdShow);
105 
106         /// <summary>
107         ///  該函數將創建指定視窗的線程設置到前臺，並且激活該視窗。鍵盤輸入轉向該視窗，併為用戶改各種可視的記號。
108         ///  系統給創建前臺視窗的線程分配的許可權稍高於其他線程。 
109         /// </summary>
110         /// <param name="hWnd">將被激活並被調入前臺的視窗句柄</param>
111         /// <returns>如果視窗設入了前臺，返回值為非零；如果視窗未被設入前臺，返回值為零</returns>
112         [DllImport("User32.dll")]
113         private static extern bool SetForegroundWindow(IntPtr hWnd);
114 
115         static Process RunningInstance()
116         {
117             Process current = Process.GetCurrentProcess();
118             Process[] processes = Process.GetProcessesByName(current.ProcessName);
119             foreach (Process process in processes)
120             {
121                 if (process.Id != current.Id)
122                 {
123                     if (process.MainModule.FileName == current.MainModule.FileName)
124                     {
125                         return process;
126                     }
127                 }
128             }
129             return null;
130         }
131 
132         private const int SW_NORMAL = 1;     //正常彈出窗體
133         private const int SW_MAXIMIZE = 3;     //最大化彈出窗體
134 
135         public static void HandleRunningInstance()
136         {
137             var instance = RunningInstance();
138             if (instance != null)
139             {
140                 ShowWindowAsync(instance.MainWindowHandle, SW_NORMAL);
141                 SetForegroundWindow(instance.MainWindowHandle);
142             }
143         }
144     }
145 }