我坚持维护的一些遗留代码陷入了无限循环（因此我自己似乎在其中）；不过，我不知道为什么/如何。
这是应用程序的入口点，它在其中实例化主窗体 (frmCentral)：
代码附件 A
public static int Main(string [] args)
{
try
{
AppDomain currentDomain = AppDomain.CurrentDomain;
currentDomain.UnhandledException += new UnhandledExceptionEventHandler(GlobalExceptionHandler);
string name = Assembly.GetExecutingAssembly().GetName().Name;
MessageBox.Show(string.Format("Executing assembly is {0}", name)); // TODO: Remove after testing <= this one is seen
IntPtr mutexHandle = CreateMutex(IntPtr.Zero, true, name);
long error = GetLastError();
MessageBox.Show(string.Format("Last error int was {0}", error.ToString())); // TODO: Remove after testing <= this one is also seen
if (error == ERROR_ALREADY_EXISTS)
{
ReleaseMutex(mutexHandle);
IntPtr hWnd = FindWindow("#NETCF_AGL_BASE_", null);
if ((int) hWnd > 0)
{
SetForegroundWindow(hWnd);
}
return 0;
}
MessageBox.Show("made it into Main method #4"); // TODO: Remove after testing <= this one is seen
ReleaseMutex(mutexHandle);
MessageBox.Show("made it into Main method #5"); // TODO: Remove after testing <= this one is seen
DeviceInfo devIn = DeviceInfo.GetInstance();
MessageBox.Show("made it into Main method #6"); // TODO: Remove after testing <= this one is seen
Wifi.DisableWifi();
MessageBox.Show("made it into Main method #7"); // TODO: Remove after testing <= this one is seen
// Instantiate a new instance of Form1.
frmCentral f1 = new frmCentral();
f1.Height = devIn.GetScreenHeight();
f1.Text = SSCS.GetFormTitle("SSCS HHS", "", "");
MessageBox.Show("made it before Application.Run() in Main method"); // TODO: Remove after testing <= this one is NOT seen
Application.Run(f1);
devIn.Close();
Application.Exit();
return 0;
}
catch(Exception ex)
{
SSCS.ExceptionHandler(ex, "Main");
return 0;
}
} // Main() method
然后 frmCentral 的构造函数调用一个名为DBConnection.GetInstance()的（与荣耀相反的是什么？）单例方法：
代码附件 B
public frmCentral()
{
try
{
//
// Required for Windows Form Designer support
//
InitializeComponent();
MessageBox.Show("made it past InitializeComponent() in frmCentral constructor"); // <= this displays
devIn = DeviceInfo.GetInstance();
MessageBox.Show("made it past DeviceInfo.GetInstance() in frmCentral constructor"); // <= this displays
dbconn = DBConnection.GetInstance();
MessageBox.Show("made it past DBConnection.GetInstance() in frmCentral constructor");
WindowState = FormWindowState.Maximized;
UpdateMenuItemSelectable = false;
ResetConnectionFetchForm = false;
AllowNewItems = true;
listboxWork.Focus();
MessageBox.Show("made it through frmCentral constructor"); // <= this one does NOT display
}
catch (Exception ex)
{
SSCS.ExceptionHandler(ex, "frmCentral()");
}
} // frmCentral Constructor
这是“美化”的单例/单例方法：
代码展览 C
// Singleton pattern, or at least a derivation thereof
public static DBConnection GetInstance()
{
MessageBox.Show("made it into DBConnection.GetInstance()");
try
{
if (instance == null)
{
MessageBox.Show("made it into DBConnection.GetInstance(); instance was null");
instance = new DBConnection();
}
}
catch(Exception ex)
{
SSCS.ExceptionHandler(ex, "DBConnection.GetInstance");
}
return instance;
}
这会实例化 DBConnection，因此调用它的构造函数：
代码展览 D
private DBConnection()
{
try
{
// Connection String
string conStr = "Data Source = " + filename;
string cmpStr = conStr + ".tmp";
MessageBox.Show(string.Format("made it into DBConnection constructor. cmpStr == {0}", cmpStr)); // TODO: Comment out or remove
if (File.Exists(filename+".tmp"))
File.Delete(filename+".tmp");
engine = new SqlCeEngine(conStr);
MessageBox.Show(string.Format("SqlCeEngine created. conStr == {0}", conStr)); // TODO: Comment out or remove
if (File.Exists(filename))
{
MessageBox.Show(string.Format("file {0} exists", filename)); // TODO: Comment out or remove
}
else
{
// Create the SQL Server CE database
engine.CreateDatabase();
MessageBox.Show("Made it past call to engine.CreateDatabase()"); // TODO: Comment out or remove
}
engine.Dispose();
objCon = new SqlCeConnection(conStr);
MessageBox.Show("Made it past call to new SqlCeConnection(conStr)"); // TODO: Comment out or remove
objCon.Open();
}
catch(Exception ex)
{
SSCS.ExceptionHandler(ex, "DBConnection.DBConnection");
}
}
我看到代码展览 A 中的 *MessageBox.Show()*s（除非另有说明），然后是代码展览 B，然后是代码展览 C，然后是代码展览 D，然后它在 C 和 D 之间来回切换“直到奶牛回家。”
我不明白为什么 DBConnection 构造函数和 DBConnection GetInstance() 递归地相互调用，虽然......我错过了大海捞针，还是隐藏在视线中的大象，或者......？？ ?
更新
public static void ExceptionHandler(Exception ex, string location)
{
try
{
MessageBox.Show("Exception: " + ex.Message + "\n\nLocation: " + location, GetFormTitle("SSCS: " + ex.GetType().FullName,"",""));
}
catch(Exception exc)
{
MessageBox.Show("Exception Handler generated an exception!\n" + exc.Message + "\n\nCalling Location: " + location, GetFormTitle("SSCS: " + exc.GetType().FullName,"",""));
}
}
更新 2
这里有更多有启发性的晦涩之处：
public static string GetFormTitle(string formName, string serialNo, string siteNo)
{
string titleBar = formName == "" ? "SSCS HHS" : formName;
if((serialNo == ""))
{
User person = new User();
person.getUserFromTable();
serialNo = person.getSerialNo();
}
if (frmCentral.HashSiteMapping.ContainsKey(siteNo))
{
siteNo = (string) frmCentral.HashSiteMapping[siteNo];
}
if (serialNo != "")
titleBar += " - " + serialNo + (siteNo == "" ? "" : " Site #" + siteNo);
return titleBar;
}
更新 3
我添加的未捕获异常代码：
currentDomain.UnhandledException += new UnhandledExceptionEventHandler(GlobalExceptionHandler);
static void GlobalExceptionHandler(object sender, UnhandledExceptionEventArgs args)
{
Exception e = (Exception)args.ExceptionObject;
MessageBox.Show(string.Format("GlobalExceptionHandler caught {0}; Compact Framework Version == {1}", e.Message, Environment.Version.ToString()));
}
不过，我还没有看到任何证据表明曾经到达过这个处理程序（到目前为止，无论如何）。
更新 4
非常有趣 - 在 GetFormTitle 添加一个 MessageBox.Show（或两个）之后：
public static string GetFormTitle(string formName, string serialNo, string siteNo)
{
MessageBox.Show(string.Format("GetFormTitle() reached. formName == {0}; serialNo == {1}; siteNo == {2}", formName, serialNo, siteNo)); // TODO: Remove after testing
string titleBar = formName == "" ? "SSCS HHS" : formName;
if((serialNo == ""))
{
User person = new User();
person.getUserFromTable();
serialNo = person.getSerialNo();
}
if (frmCentral.HashSiteMapping.ContainsKey(siteNo))
{
siteNo = (string) frmCentral.HashSiteMapping[siteNo];
}
if (serialNo != "")
titleBar += " - " + serialNo + (siteNo == "" ? "" : " Site #" + siteNo);
MessageBox.Show(string.Format("titleBar val about to be returned. Val is {0}", titleBar)); // TODO: Remove after testing
return titleBar;
}
...这些是我现在看到的 MessageBox.Show() 的序列：
0) Made it into DBConnection.GetInstance()
1) Made it into DBConnection.GetInstance() instance was null
2) Made it to DBConnection constructor cmpStr == ....
3) Sqlceengine created. conStr == ...
4) File \My Documents\HHSDB.SDF exists
5) Made it past call to new SqlCeConnection(conStr)
6) GetFormTitle() reached. fromName == SSCS:
System.Data.SqlserverCe.SqlCeException; serial No ==; siteNo ==
...随后是一轮更追尾的递归消息，直到我热启动（我讨厌与 Fab 4 相矛盾，但与流行的观点相反，幸福绝对不是热启动！*）
...所以就在 MessageBox 消息显示的中间，插入了一个异常！完全宾夕法尼亚嘻哈（关键说唱）！
* Let's have no attempts at humor revolving around warm booty, now!
那是远程桌面调试的最高级展示，LB2！