ErrorEventArgs (Clase)
Ensamblado: System (en system.dll)
ErrorEventArgs contiene el objeto Exception que ocasionó el evento Error. La clase proporciona el método GetException necesario para recuperar la excepción.
En el siguiente ejemplo se crea una nueva instancia de ErrorEventArgs y la inicializa con Exception. A continuación, el ejemplo llama a GetException para recuperar Exception y mostrar el mensaje de error. No hay ningún formulario asociado a este código.
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); }
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
En el siguiente ejemplo de código se muestra cómo se crea un objeto FileSystemWatcher para supervisar los cambios en archivos (crear, eliminar, cambiar el nombre, modificar) que se producen en una unidad de disco. El ejemplo también muestra cómo se reciben correctamente las notificaciones de error.
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
Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center, Windows XP Professional x64, Windows XP SP2, Windows XP Starter Edition
.NET Framework no admite todas las versiones de cada plataforma. Para obtener una lista de las versiones admitidas, vea Requisitos del sistema.