в 16:40, 26 мая 2010

2010-05-26T16:40:06Z

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2010-05-26T12:42:17Z

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==Any Exception generatesd will be caught in the Catch block that follows==

<source lang="vbnet">
Imports System
Public Class MainClass
Shared Sub Main()
Try
Method1()
" Output String representation of Exception, then output
" values of properties InnerException, Message and StackTrace
Catch exceptionParameter As Exception
Console.WriteLine("exceptionParameter.ToString: " & _
vbCrLf & "{0}" & vbCrLf, exceptionParameter.ToString())
Console.WriteLine("exceptionParameter.Message: " & _
vbCrLf & "{0}" & vbCrLf, exceptionParameter.Message)
Console.WriteLine("exceptionParameter.StackTrace: " & _
vbCrLf & "{0}" & vbCrLf, exceptionParameter.StackTrace)
Console.WriteLine( _
"exceptionParameter.InnerException: " & _
vbCrLf & "{0}" & vbCrLf, _
exceptionParameter.InnerException.ToString())
End Try
End Sub " Main
Public Shared Sub Method1()
Method2()
End Sub
Public Shared Sub Method2()
Method3()
End Sub
Public Shared Sub Method3()
" attempt to convert String to Integer
Try
Convert.ToInt32("Not an integer")
Catch formatException As FormatException
Throw New Exception("Exception occurred in Method3", _
formatException)
End Try
End Sub
End Class

</source>

==Catch and rethrow exceptions==

<source lang="vbnet">
Imports System
Imports System.Data
Imports System.IO
public class MainClass
Shared Sub Main()
Dim FileToRead As String = "test.txt"
Dim TestFile As FileStream
Dim Reader As New StreamReader(FileToRead)
Do
Dim I As Integer, S As String
Dim Result As Integer
Try
S = Reader.ReadLine()
I = CInt(S)
Result = 100 \ I
Console.WriteLine(Result)
Catch DivByZero As System.DivideByZeroException
Console.WriteLine("** Divide by zero **")
Catch BadConversion As System.InvalidCastException
Console.WriteLine("** " + S + " is not a number **")
Throw New System.InvalidCastException("My own exception happened here", BadConversion)
Catch OtherErrors As Exception
Throw OtherErrors
End Try
Loop While Reader.Peek <> -1
End Sub
End Class

</source>

==Exception occurs and caught, then rethrown to caller==

<source lang="vbnet">
Imports System
Public Class MainClass

Shared Sub Main(ByVal args As String())
Console.WriteLine("Calling ThrowExceptionCatchRethrow")
Try
ThrowExceptionCatchRethrow()
Catch
Console.WriteLine("Caught exception from " & _
"ThrowExceptionCatchRethrow in Main")
End Try
End Sub
Public Shared Sub ThrowExceptionCatchRethrow()
Try
Console.WriteLine("In ThrowExceptionCatchRethrow")
Throw New Exception("Exception in ThrowExceptionCatchRethrow")
Catch exceptionParameter As Exception
Console.WriteLine("Message: " & exceptionParameter.Message)
Throw exceptionParameter
Finally
Console.WriteLine("Finally executed in ThrowException")
End Try
" any code placed here is never reached
Console.WriteLine("End of ThrowExceptionCatchRethrow")
End Sub
End Class

</source>

==Throw an Exception==

<source lang="vbnet">
Imports System
Imports System.Configuration
Imports System.Resources " Resource readers
Public Class MainClass

Shared Sub Main()
Throw New System.IO.FileLoadException()
End Sub
End Class

</source>

==Throw an Exception from a Function==

<source lang="vbnet">
Imports System
Imports System.Text
Imports System.Text.RegularExpressions
Public Class MainClass
Shared Sub Main(ByVal args As String())
Console.WriteLine("Enter Run...")
Func1( )
Console.WriteLine("Exit Run...")
End Sub

Shared Public Sub Func1( )
Console.WriteLine("Enter Func1...")
Func2( )
Console.WriteLine("Exit Func1...")
End Sub "Func1
Shared Public Sub Func2( )
Console.WriteLine("Enter Func2...")
Throw New System.Exception( )
Console.WriteLine("Exit Func2...")
End Sub "Func2
End Class

</source>

==Throw Exception Without Catch==

<source lang="vbnet">
Imports System
Public Class MainClass

Shared Sub Main(ByVal args As String())
Try
ThrowExceptionWithoutCatch()
Catch
Console.WriteLine("Caught exception from " & _
"ThrowExceptionWithoutCatch in Main")
End Try
End Sub
Shared Public Sub ThrowExceptionWithoutCatch()
Try
Console.WriteLine("In ThrowExceptionWithoutCatch")
Throw New Exception( _
"Exception in ThrowExceptionWithoutCatch")
Finally
Console.WriteLine("Finally executed in " & _
"ThrowExceptionWithoutCatch")
End Try
" unreachable code; logic error
Console.WriteLine("End")
End Sub

End Class

</source>

==Throws exception and catches it locally==

<source lang="vbnet">
Imports System
Public Class MainClass

Shared Sub Main(ByVal args As String())

" Try block throws exception
Try
Console.WriteLine("In Throw Exception With Catch")
Throw New Exception("Exception in Throw Exception With Catch")
" catch exception thrown in Try block
Catch exceptionParameter As Exception
Console.WriteLine("Message: " & exceptionParameter.Message)
" Finally executes because corresponding Try executed
Finally
Console.WriteLine( _
"Finally executed in Throw Exception With Catch")
End Try
Console.WriteLine("End")
End Sub
End Class

</source>

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в 16:40, 26 мая 2010

Admin: 1 версия