How call customer exeption

Question

I chave create my exeption class but when i call my exeption show box with this exeption and program stop. using System.Collections.Generic; using System.Text; using System.Runtime.Serialiazation; namespace MyToolBar { public class MyXmlExeption : Exception { public MyXmlExeption() : base() { } public MyXmlExeption(string message) : base(message) { } public MyXmlExeption(string message Exception e) : base(message e) { } } } and here i check when i will call my exeption foreach (XmlAttribute atr in ch.Attributes) { if (atr.Name == img && atr.Value == ) throw new MyXmlExeption(Picture not found in xml file); if (atr.Name == id) button1.Name = atr.Value; if (atr.Name == img) { button1.BackgroundImage = Image.FromFile(atr.Value); } if (atr.Name == text) button1.Text = atr.Value; } and here i call my exeption thrd = new Thread(new ParameterizedThreadStart(toolBar1.XmlLoad)); try { //?????? ?????? ? ??????????? thrd.Start(xmlPath); } catch (MyXmlExeption ex) { }

Zoran Horvat · Answer

Do not start thread like this: thrd.Start(xmlPath); Instead write a state class which contains XML path and exception e.g. like this: public class State { public State() { } public State(string xmlPath) { _xmlPath = xmlPath; } public Exception Exception { get { return _exception; } set { _exception = value; } } public string XmlPath { get { return _xmlPath; } set { _xmlPath = value; } } private Exception _exception; private string _xmlPath; } Now start the thread like this: thrd.Start(new State(xmlPath)); Then in the thread procedure don't miss to catch ALL exceptions: void ThreadProc(object state) { State s = (State)state; s.Exception = null; // Indicates that there was no exception try { // Do work } catch (System.Exception ex) { s.Exception = ex; } } Once the thread exits you can test state's Exception property to see if there was any exception on the thread. Zoran

Anil Kumar · Answer

Wonderful ... Zoran

Mike Jonson · Answer

Thank you Zoran))) Undestand now more

Zoran Horvat · Answer

Dimitri Did this solve the problem? Zoran

Zoran Horvat · Answer

That is the method in which you had this code: foreach (XmlAttribute atr in ch.Attributes) { if (atr.Name == img && atr.Value == ) throw new MyXmlExeption(Picture not found in xml file); if (atr.Name == id) button1.Name = atr.Value; if (atr.Name == img) { button1.BackgroundImage = Image.FromFile(atr.Value); } if (atr.Name == text) button1.Text = atr.Value; } Actually this foreach loop is the piece of code that I marked with // Do work. It is only important to have throw new MyXmlException... line wrapped in try...catch (System.Exception) block. Zoran

Mike Jonson · Answer

and whe i need use method void ThreadProc(object state) { State s = (State)state; s.Exception = null; // Indicates that there was no exception try { // Do work } catch (System.Exception ex) { s.Exception = ex; } } and what add in parameter?

Zoran Horvat · Answer

In your first post you have put this code: thrd = new Thread(new ParameterizedThreadStart(toolBar1.XmlLoad)); try { //?????? ?????? ? ??????????? thrd.Start(xmlPath); } catch (MyXmlExeption ex) { } Instead of thrd.Start(xmlPath) you should call thrd.Start(new State(xmlPath)). Zoran

Mike Jonson · Answer

Whe i need add: thrd.Start(new State(xmlPath))?

Mike Jonson · Answer

i see but cant undestand how then call my exeption in another theads example in my class form1

Zoran Horvat · Answer

Dimitri You are throwing exception on one thread and catching it on another thread. That doesn't work. You have to catch the exception on the same thread on which it was thrown and then to pass that information to the other thread yourself. Please refer to my second listing for complete solution. Zoran

Mike Jonson · Answer

please check file its picture with error

Zoran Horvat · Answer

You can't catch exception from where you start the thread because that code executes on another thread. thrd is the thread which throws exception and exception must be caught on that thread. You can help collect information about the unhandled exception on another thread using this code: using System; using System.Threading; using System.Windows.Forms; namespace ExceptionTest { class Program { static void ThreadProc() { throw new System.Exception(); } static void Main(string[] args) { Application.SetUnhandledExceptionMode(UnhandledExceptionMode.CatchException); AppDomain.CurrentDomain.UnhandledException += new UnhandledExceptionEventHandler(CurrentDomain_UnhandledException); _thread = new Thread(new ThreadStart(ThreadProc)); _thread.Start(); _thread.Join(); Console.WriteLine(Press ENTER to continue...); Console.ReadLine(); } static void CurrentDomain_UnhandledException(object sender UnhandledExceptionEventArgs e) { Console.WriteLine(e.ExceptionObject); } static Thread _thread; } } In this example unhandled exception will be logged but that cannot prevent application from stopping. The only way to keep running is to handle the exception on the thread which raises it: try { foreach (XmlAttribute atr in ch.Attributes) { if (atr.Name == img && atr.Value == ) throw new MyXmlExeption(Picture not found in xml file); if (atr.Name == id) button1.Name = atr.Value; if (atr.Name == img) { button1.BackgroundImage = Image.FromFile(atr.Value); } if (atr.Name == text) button1.Text = atr.Value; } } catch (MyXmlException ex) { // Report error } Reporting the error may include sending information about the exception to the caller. Here is the modified code which handles exception on the thread and passes it nicely to the entity which has started the thread: using System; using System.Threading; using System.Windows.Forms; namespace ExceptionTest { class State { public Exception Exception { get { return _exception; } set { _exception = value; } } private Exception _exception; } class Program { static void ThreadProc(object state) { State s = (State)state; try { // Do work throw new System.Exception(); } catch (System.Exception ex) { s.Exception = ex; } } static void Main(string[] args) { State state = new State(); Application.SetUnhandledExceptionMode(UnhandledExceptionMode.CatchException); AppDomain.CurrentDomain.UnhandledException += new UnhandledExceptionEventHandler(CurrentDomain_UnhandledException); _thread = new Thread(new ParameterizedThreadStart(ThreadProc)); _thread.Start(state); _thread.Join(); if (state.Exception != null) Console.WriteLine(Exception occurred on thread: {0} state.Exception); Console.WriteLine(Press ENTER to continue...); Console.ReadLine(); } static void CurrentDomain_UnhandledException(object sender UnhandledExceptionEventArgs e) { Console.WriteLine(e.ExceptionObject); } static Thread _thread; protected Exception _threadException; } } Zoran

Dorababu Meka · Answer

Didn't get you you don't want to close the application or what

Mike Jonson · Answer

have change but show message with the text of this error and program not go

Dorababu Meka · Answer

Not clear about your requirement do you want to throw the exception or what if so write catch (MyXmlExeption ex) { throw ex; //You can show that using message box if you are using WINFORMS messagebox.show(ex.tostring()); or you can write to console as follows Console . WriteLine ( ex . ToString ()); }