Overloads Public Shared Sub Main(args() As String)
' Creates an exception with an error message.
Dim myException As New Exception("This is an exception test")
' Creates an ErrorEventArgs with the exception.
Dim myErrorEventArgs As New ErrorEventArgs(myException)
' Extracts the exception from the ErrorEventArgs and display it.
Dim myReturnedException As Exception = myErrorEventArgs.GetException()
MessageBox.Show(("The returned exception is: " & myReturnedException.Message))
End Sub 'Main
public static void Main(string[] args) {
// Creates an exception with an error message.
Exception myException= new Exception("This is an exception test");
// Creates an ErrorEventArgs with the exception.
ErrorEventArgs myErrorEventArgs = new ErrorEventArgs(myException);
// Extracts the exception from the ErrorEventArgs and display it.
Exception myReturnedException = myErrorEventArgs.GetException();
MessageBox.Show("The returned exception is: " + myReturnedException.Message);
}
int main()
{
// Creates an exception with an error message.
Exception^ myException = gcnew Exception( "This is an exception test" );
// Creates an ErrorEventArgs with the exception.
ErrorEventArgs^ myErrorEventArgs = gcnew ErrorEventArgs( myException );
// Extracts the exception from the ErrorEventArgs and display it.
Exception^ myReturnedException = myErrorEventArgs->GetException();
MessageBox::Show( String::Concat( "The returned exception is: ", myReturnedException->Message ) );
}
public static void main(String[] args)
{
// Creates an exception with an error message.
Exception myException = new Exception("This is an exception test");
// Creates an ErrorEventArgs with the exception.
ErrorEventArgs myErrorEventArgs = new ErrorEventArgs(myException);
// Extracts the exception from the ErrorEventArgs and display it.
System.Exception myReturnedException =
myErrorEventArgs.GetException();
MessageBox.Show("The returned exception is: "
+ myReturnedException.get_Message());
} //main
FileSystemWatcher を作成し、ディスク ドライブ上でのファイルの変更 (作成、削除、名前変更、変更) を監視する例を次に示します。この例では、エラーの通知を正しく受け取る方法も示されています。
Imports System.IO
Module Module1
Sub Main()
' Create a FileSystemWatcher to monitor all files on drive C.
Dim fsw As New FileSystemWatcher("C:\")
' Watch for changes in LastAccess and LastWrite times, and
' the renaming of files or directories.
fsw.NotifyFilter = (NotifyFilters.LastAccess Or NotifyFilters.LastWrite _
Or NotifyFilters.FileName Or NotifyFilters.DirectoryName)
' Register a handler that gets called when a
' file is created, changed, or deleted.
AddHandler fsw.Changed, New FileSystemEventHandler(AddressOf OnChanged)
' The commented line of code below is a shorthand of the above line.
' AddHandler fsw.Changed, AddressOf OnChanged
' NOTE: The shorthand version is used in the remainder of this code.
' FileSystemEventHandler
AddHandler fsw.Created, AddressOf OnChanged
' FileSystemEventHandler
AddHandler fsw.Deleted, AddressOf OnChanged
' Register a handler that gets called when a file is renamed.
' RenamedEventHandler
AddHandler fsw.Renamed, AddressOf OnRenamed
' Register a handler that gets called if the
' FileSystemWatcher needs to report an error.
' ErrorEventHandler
AddHandler fsw.Error, AddressOf OnError
' Begin watching.
fsw.EnableRaisingEvents = True
' Wait for the user to quit the program.
Console.WriteLine("Press 'Enter' to quit the sample.")
Console.ReadLine()
End Sub
' This method is called when a file is created, changed, or deleted.
Private Sub OnChanged(ByVal source As Object, ByVal e As FileSystemEventArgs)
' Show that a file has been created, changed, or deleted.
Dim wct As WatcherChangeTypes = e.ChangeType
Console.WriteLine("File {0} {1}", e.FullPath, wct.ToString())
End Sub
' This method is called when a file is renamed.
Private Sub OnRenamed(ByVal source As Object, ByVal e As RenamedEventArgs)
' Show that a file has been renamed.
Dim wct As WatcherChangeTypes = e.ChangeType
Console.WriteLine("File {0} {2} to {1}", e.OldFullPath, e.FullPath, wct.ToString())
End Sub
' This method is called when the FileSystemWatcher detects an error.
Private Sub OnError(ByVal source As Object, ByVal e As ErrorEventArgs)
' Show that an error has been detected.
Console.WriteLine("The FileSystemWatcher has detected an error")
' Give more information if the error is due to an internal buffer overflow.
If TypeOf e.GetException Is InternalBufferOverflowException Then
' This can happen if Windows is reporting many file system events quickly
' and internal buffer of the FileSystemWatcher is not large enough to handle this
' rate of events. The InternalBufferOverflowException error informs the application
' that some of the file system events are being lost.
Console.WriteLine( _
"The file system watcher experienced an internal buffer overflow: " _
+ e.GetException.Message)
End If
End Sub
End Module