FirstChanceExceptionEventArgs Kelas
Definisi
Penting
Beberapa informasi terkait produk prarilis yang dapat diubah secara signifikan sebelum dirilis. Microsoft tidak memberikan jaminan, tersirat maupun tersurat, sehubungan dengan informasi yang diberikan di sini.
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
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.Exception
FirstChanceHandler
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) |