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FirstChanceExceptionEventArgs Kelas

  • Referensi

Definisi

Ruang nama:
System.Runtime.ExceptionServices
Rakitan:
System.Runtime.dll
Rakitan:
mscorlib.dll
Rakitan:
netstandard.dll
Sumber:
FirstChanceExceptionEventArgs.cs
Sumber:
FirstChanceExceptionEventArgs.cs
Sumber:
FirstChanceExceptionEventArgs.cs

Menyediakan data untuk peristiwa pemberitahuan yang dimunculkan saat pengecualian terkelola pertama kali terjadi, sebelum runtime bahasa umum mulai mencari penanganan aktivitas.

public ref class FirstChanceExceptionEventArgs : EventArgs
public class FirstChanceExceptionEventArgs : EventArgs
type FirstChanceExceptionEventArgs = class
    inherit EventArgs
Public Class FirstChanceExceptionEventArgs
Inherits EventArgs
Warisan
Object
EventArgs
FirstChanceExceptionEventArgs

Contoh

Contoh berikut membuat serangkaian domain aplikasi bernama Child_0 melalui Child_3, dengan Worker objek di setiap domain aplikasi. Setiap Worker objek memiliki referensi ke Worker objek di domain aplikasi berikutnya, kecuali di Worker domain aplikasi terakhir. Peristiwa FirstChanceException ini ditangani di semua domain aplikasi kecuali Child_1.

Ketika domain aplikasi telah dibuat, domain aplikasi default memanggil TestException metode untuk domain aplikasi anak pertama. Setiap Worker objek memanggil TestException metode untuk berikutnya, sampai yang terakhir Worker melempar pengecualian yang ditangani atau tidak tertangani. Dengan demikian, utas saat ini melewati semua domain aplikasi, dan TestException ditambahkan ke tumpukan di setiap domain aplikasi.

Ketika objek terakhir Worker menangani pengecualian, FirstChanceException peristiwa hanya dinaikkan di domain aplikasi terakhir. Domain aplikasi lain tidak pernah mendapatkan kesempatan untuk menangani pengecualian, sehingga peristiwa tidak dinaikkan.

Ketika objek terakhir Worker tidak menangani pengecualian, FirstChanceException peristiwa dinaikkan di setiap domain aplikasi yang memiliki penanganan aktivitas. Setelah setiap penanganan aktivitas selesai, tumpukan terus melepas lelah hingga pengecualian ditangkap oleh domain aplikasi default.

Catatan

Untuk melihat bagaimana tampilan tumpukan tumbuh saat peristiwa dinaikkan lebih dekat dan lebih dekat ke domain aplikasi default, ubah e.Exception.Message ke e.ExceptionFirstChanceHandler di penanganan aktivitas. Perhatikan bahwa ketika TestException dipanggil di seluruh batas domain aplikasi, itu muncul dua kali: sekali untuk proksi dan sekali untuk stub.

using System;
using System.Reflection;
using System.Runtime.ExceptionServices;

class FirstChanceExceptionSnippet
{
    static void Main()
    {
        AppDomain.CurrentDomain.FirstChanceException += FirstChanceHandler;

        // Create a set of application domains, with a Worker object in each one.
        // Each Worker object creates the next application domain.
        AppDomain ad = AppDomain.CreateDomain("AD0");
        Worker w = (Worker) ad.CreateInstanceAndUnwrap(
                                typeof(Worker).Assembly.FullName, "Worker");
        w.Initialize(0, 3);

        Console.WriteLine("\r\nThe last application domain throws an exception and catches it:");
        Console.WriteLine();
        w.TestException(true);

        try
        {
            Console.WriteLine(
                "\r\nThe last application domain throws an exception and does not catch it:");
            Console.WriteLine();
            w.TestException(false);
        }
        catch (ArgumentException ex)
        {
            Console.WriteLine("ArgumentException caught in {0}: {1}",
                AppDomain.CurrentDomain.FriendlyName, ex.Message);
        }
    }

    static void FirstChanceHandler(object source, FirstChanceExceptionEventArgs e)
    {
        Console.WriteLine("FirstChanceException event raised in {0}: {1}",
            AppDomain.CurrentDomain.FriendlyName, e.Exception.Message);
    }
}

public class Worker : MarshalByRefObject
{
    private AppDomain ad = null;
    private Worker w = null;

    public void Initialize(int count, int max)
    {
        // Handle the FirstChanceException event in all application domains except
        // AD1.
        if (count != 1)
        {
            AppDomain.CurrentDomain.FirstChanceException += FirstChanceHandler;
        }

        // Create another application domain, until the maximum is reached.
        // Field w remains null in the last application domain, as a signal
        // to TestException().
        if (count < max)
        {
            int next = count + 1;
            ad = AppDomain.CreateDomain("AD" + next);
            w = (Worker) ad.CreateInstanceAndUnwrap(
                             typeof(Worker).Assembly.FullName, "Worker");
            w.Initialize(next, max);
        }
    }

    public void TestException(bool handled)
    {
        // As long as there is another application domain, call TestException() on
        // its Worker object. When the last application domain is reached, throw a
        // handled or unhandled exception.
        if (w != null)
        {
            w.TestException(handled);
        }
        else if (handled)
        {
            try
            {
                throw new ArgumentException("Thrown in " + AppDomain.CurrentDomain.FriendlyName);
            }
            catch (ArgumentException ex)
            {
                Console.WriteLine("ArgumentException caught in {0}: {1}",
                    AppDomain.CurrentDomain.FriendlyName, ex.Message);
            }
        }
        else
        {
            throw new ArgumentException("Thrown in " + AppDomain.CurrentDomain.FriendlyName);
        }
    }

    static void FirstChanceHandler(object source, FirstChanceExceptionEventArgs e)
    {
        Console.WriteLine("FirstChanceException event raised in {0}: {1}",
            AppDomain.CurrentDomain.FriendlyName, e.Exception.Message);
    }
}

/* This example produces output similar to the following:

The last application domain throws an exception and catches it:

FirstChanceException event raised in AD3: Thrown in AD3
ArgumentException caught in AD3: Thrown in AD3

The last application domain throws an exception and does not catch it:

FirstChanceException event raised in AD3: Thrown in AD3
FirstChanceException event raised in AD2: Thrown in AD3
FirstChanceException event raised in AD0: Thrown in AD3
FirstChanceException event raised in Example.exe: Thrown in AD3
ArgumentException caught in Example.exe: Thrown in AD3
 */

Imports System.Reflection
Imports System.Runtime.ExceptionServices

Class Example

    Shared Sub Main()
    
        AddHandler AppDomain.CurrentDomain.FirstChanceException, AddressOf FirstChanceHandler

        ' Create a set of application domains, with a Worker object in each one.
        ' Each Worker object creates the next application domain.
        Dim ad As AppDomain = AppDomain.CreateDomain("AD0")
        Dim w As Worker = CType(ad.CreateInstanceAndUnwrap(
                                GetType(Worker).Assembly.FullName, "Worker"),
                                Worker)
        w.Initialize(0, 3)

        Console.WriteLine(vbCrLf & "The last application domain throws an exception and catches it:")
        Console.WriteLine()
        w.TestException(true)

        Try
            Console.WriteLine(vbCrLf & 
                "The last application domain throws an exception and does not catch it:")
            Console.WriteLine()
            w.TestException(false) 

        Catch ex As ArgumentException
        
            Console.WriteLine("ArgumentException caught in {0}: {1}", 
                AppDomain.CurrentDomain.FriendlyName, ex.Message)
        End Try
    End Sub

    Shared Sub FirstChanceHandler(ByVal source As Object, 
                                  ByVal e As FirstChanceExceptionEventArgs)
    
        Console.WriteLine("FirstChanceException event raised in {0}: {1}",
            AppDomain.CurrentDomain.FriendlyName, e.Exception.Message)
    End Sub
End Class

Public Class Worker
    Inherits MarshalByRefObject

    Private ad As AppDomain = Nothing
    Private w As Worker = Nothing

    Public Sub Initialize(ByVal count As Integer, ByVal max As Integer)
    
        ' Handle the FirstChanceException event in all application domains except
        ' AD1.
        If count <> 1
        
            AddHandler AppDomain.CurrentDomain.FirstChanceException, AddressOf FirstChanceHandler

        End If

        ' Create another application domain, until the maximum is reached.
        ' Field w remains Nothing in the last application domain, as a signal 
        ' to TestException(). 
        If count < max
            Dim nextAD As Integer = count + 1
            ad = AppDomain.CreateDomain("AD" & nextAD)
            w = CType(ad.CreateInstanceAndUnwrap(
                      GetType(Worker).Assembly.FullName, "Worker"),
                      Worker)
            w.Initialize(nextAD, max)
        End If
    End Sub

    Public Sub TestException(ByVal handled As Boolean)
    
        ' As long as there is another application domain, call TestException() on
        ' its Worker object. When the last application domain is reached, throw a
        ' handled or unhandled exception.
        If w IsNot Nothing
        
            w.TestException(handled)

        Else If handled
        
            Try
                Throw New ArgumentException("Thrown in " & AppDomain.CurrentDomain.FriendlyName)

            Catch ex As ArgumentException
            
                Console.WriteLine("ArgumentException caught in {0}: {1}", 
                    AppDomain.CurrentDomain.FriendlyName, ex.Message)
            End Try
        Else
        
            Throw New ArgumentException("Thrown in " & AppDomain.CurrentDomain.FriendlyName)
        End If
    End Sub

    Shared Sub FirstChanceHandler(ByVal source As Object, 
                                  ByVal e As FirstChanceExceptionEventArgs)
    
        Console.WriteLine("FirstChanceException event raised in {0}: {1}",
            AppDomain.CurrentDomain.FriendlyName, e.Exception.Message)
    End Sub
End Class

' This example produces output similar to the following:
'
'The last application domain throws an exception and catches it:
'
'FirstChanceException event raised in AD3: Thrown in AD3
'ArgumentException caught in AD3: Thrown in AD3
'
'The last application domain throws an exception and does not catch it:
'
'FirstChanceException event raised in AD3: Thrown in AD3
'FirstChanceException event raised in AD2: Thrown in AD3
'FirstChanceException event raised in AD0: Thrown in AD3
'FirstChanceException event raised in Example.exe: Thrown in AD3
'ArgumentException caught in Example.exe: Thrown in AD3

Keterangan

Kelas ini menyediakan handler pengecualian untuk AppDomain.FirstChanceException peristiwa dengan akses ke pengecualian.

Konstruktor

FirstChanceExceptionEventArgs(Exception)

Menginisialisasi instans FirstChanceExceptionEventArgs baru kelas dengan pengecualian tertentu.

Properti

Exception

Objek pengecualian terkelola yang sesuai dengan pengecualian yang dilemparkan dalam kode terkelola.

Metode

Equals(Object)

Menentukan apakah objek yang ditentukan sama dengan objek saat ini.

(Diperoleh dari Object)
GetHashCode()

Berfungsi sebagai fungsi hash default.

(Diperoleh dari Object)
GetType()

Mendapatkan dari instans Type saat ini.

(Diperoleh dari Object)
MemberwiseClone()

Membuat salinan dangkal dari saat ini Object.

(Diperoleh dari Object)
ToString()

Mengembalikan string yang mewakili objek saat ini.

(Diperoleh dari Object)

Berlaku untuk

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