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Exception.HelpLink Proprietà

Definizione

Ottiene o imposta un collegamento al file della Guida associato all'eccezione.

public:
 virtual property System::String ^ HelpLink { System::String ^ get(); void set(System::String ^ value); };
public virtual string HelpLink { get; set; }
public virtual string? HelpLink { get; set; }
member this.HelpLink : string with get, set
Public Overridable Property HelpLink As String

Valore della proprietà

URN (Uniform Resource Name) o URL (Uniform Resource Locator).

Implementazioni

Esempio

L'esempio di codice seguente genera un oggetto Exception che imposta la HelpLink proprietà nel costruttore e quindi rileva l'eccezione e visualizza HelpLink.

// Example for the Exception::HelpLink, Exception::Source,
// Exception::StackTrace, and Exception::TargetSite properties.
using namespace System;

namespace NDP_UE_CPP
{

   // Derive an exception; the constructor sets the HelpLink and 
   // Source properties.
   public ref class LogTableOverflowException: public Exception
   {
   private:
      static String^ overflowMessage = "The log table has overflowed.";

   public:
      LogTableOverflowException( String^ auxMessage, Exception^ inner )
         : Exception( String::Format( "{0} - {1}", overflowMessage, auxMessage ), inner )
      {
         this->HelpLink = "https://learn.microsoft.com";
         this->Source = "Exception_Class_Samples";
      }

   };

   public ref class LogTable
   {
   public:
      LogTable( int numElements )
      {
         logArea = gcnew array<String^>(numElements);
         elemInUse = 0;
      }


   protected:
      array<String^>^logArea;
      int elemInUse;

   public:

      // The AddRecord method throws a derived exception if 
      // the array bounds exception is caught.
      int AddRecord( String^ newRecord )
      {
         try
         {
            logArea[ elemInUse ] = newRecord;
            return elemInUse++;
         }
         catch ( Exception^ ex ) 
         {
            throw gcnew LogTableOverflowException( String::Format( "Record \"{0}\" was not logged.", newRecord ),ex );
         }

      }

   };


   // Create a log table and force an overflow.
   void ForceOverflow()
   {
      LogTable^ log = gcnew LogTable( 4 );
      try
      {
         for ( int count = 1; ; count++ )
         {
            log->AddRecord( String::Format( "Log record number {0}", count ) );

         }
      }
      catch ( Exception^ ex ) 
      {
         Console::WriteLine( "\nMessage ---\n{0}", ex->Message );
         Console::WriteLine( "\nHelpLink ---\n{0}", ex->HelpLink );
         Console::WriteLine( "\nSource ---\n{0}", ex->Source );
         Console::WriteLine( "\nStackTrace ---\n{0}", ex->StackTrace );
         Console::WriteLine( "\nTargetSite ---\n{0}", ex->TargetSite->ToString() );
      }

   }

}

int main()
{
   Console::WriteLine( "This example of \n   Exception::Message, \n"
   "   Exception::HelpLink, \n   Exception::Source, \n"
   "   Exception::StackTrace, and \n   Exception::"
   "TargetSite \ngenerates the following output." );
   NDP_UE_CPP::ForceOverflow();
}

/*
This example of
   Exception::Message,
   Exception::HelpLink,
   Exception::Source,
   Exception::StackTrace, and
   Exception::TargetSite
generates the following output.

Message ---
The log table has overflowed. - Record "Log record number 5" was not logged.

HelpLink ---
https://learn.microsoft.com

Source ---
Exception_Class_Samples

StackTrace ---
   at NDP_UE_CPP.LogTable.AddRecord(String newRecord)
   at NDP_UE_CPP.ForceOverflow()

TargetSite ---
Int32 AddRecord(System.String)
*/
// Example for the Exception.HelpLink, Exception.Source,
// Exception.StackTrace, and Exception.TargetSite properties.
using System;

namespace NDP_UE_CS
{
    // Derive an exception; the constructor sets the HelpLink and
    // Source properties.
    class LogTableOverflowException : Exception
    {
        const string overflowMessage = "The log table has overflowed.";

        public LogTableOverflowException(
            string auxMessage, Exception inner ) :
                base( String.Format( "{0} - {1}",
                    overflowMessage, auxMessage ), inner )
        {
            this.HelpLink = "https://learn.microsoft.com";
            this.Source = "Exception_Class_Samples";
        }
    }

    class LogTable
    {
        public LogTable( int numElements )
        {
            logArea = new string[ numElements ];
            elemInUse = 0;
        }

        protected string[ ] logArea;
        protected int       elemInUse;

        // The AddRecord method throws a derived exception if
        // the array bounds exception is caught.
        public    int       AddRecord( string newRecord )
        {
            try
            {
                logArea[ elemInUse ] = newRecord;
                return elemInUse++;
            }
            catch( Exception e )
            {
                throw new LogTableOverflowException(
                    String.Format( "Record \"{0}\" was not logged.",
                        newRecord ), e );
            }
        }
    }

    class OverflowDemo
    {
        // Create a log table and force an overflow.
        public static void Main()
        {
            LogTable log = new LogTable( 4 );

            Console.WriteLine(
                "This example of \n   Exception.Message, \n" +
                "   Exception.HelpLink, \n   Exception.Source, \n" +
                "   Exception.StackTrace, and \n   Exception." +
                "TargetSite \ngenerates the following output." );

            try
            {
                for( int count = 1; ; count++ )
                {
                    log.AddRecord(
                        String.Format(
                            "Log record number {0}", count ) );
                }
            }
            catch( Exception ex )
            {
                Console.WriteLine( "\nMessage ---\n{0}", ex.Message );
                Console.WriteLine(
                    "\nHelpLink ---\n{0}", ex.HelpLink );
                Console.WriteLine( "\nSource ---\n{0}", ex.Source );
                Console.WriteLine(
                    "\nStackTrace ---\n{0}", ex.StackTrace );
                Console.WriteLine(
                    "\nTargetSite ---\n{0}", ex.TargetSite );
            }
        }
    }
}

/*
This example of
   Exception.Message,
   Exception.HelpLink,
   Exception.Source,
   Exception.StackTrace, and
   Exception.TargetSite
generates the following output.

Message ---
The log table has overflowed. - Record "Log record number 5" was not logged.

HelpLink ---
https://learn.microsoft.com

Source ---
Exception_Class_Samples

StackTrace ---
   at NDP_UE_CS.LogTable.AddRecord(String newRecord)
   at NDP_UE_CS.OverflowDemo.Main()

TargetSite ---
Int32 AddRecord(System.String)
*/
// Example for the Exception.HelpLink, Exception.Source,
// Exception.StackTrace, and Exception.TargetSite properties.
open System
        
let overflowMessage = "The log table has overflowed."

// Derive an exception; the constructor sets the HelpLink and
// Source properties.
type LogTableOverflowException(auxMessage, inner) as this =
    inherit Exception($"%s{overflowMessage} - %s{auxMessage}", inner)

    do
        this.HelpLink <- "https://learn.microsoft.com"
        this.Source <- "Exception_Class_Samples"

type LogTable(numElements) =
    let logArea = Array.zeroCreate<string> numElements
    let mutable elemInUse = 0

    // The AddRecord method throws a derived exception if
    // the array bounds exception is caught.
    member this.AddRecord(newRecord) =
        try
            logArea[elemInUse] <- newRecord
            elemInUse <- elemInUse + 1
            elemInUse - 1 
        with e ->
            raise (LogTableOverflowException($"Record \"{newRecord}\" was not logged.", e) )

// Create a log table and force an overflow.
let log = LogTable 4 

printfn
    """This example of
   Exception.Message, 
   Exception.HelpLink, 
   Exception.Source, 
   Exception.StackTrace, and
   Exception.TargetSite 
   generates the following output."""

try
    for count = 1 to 1000000 do
        log.AddRecord $"Log record number {count}"
        |> ignore
with ex ->
    printfn $"\nMessage ---\n{ex.Message}"
    printfn $"\nHelpLink ---\n{ex.HelpLink}"
    printfn $"\nSource ---\n{ex.Source}"
    printfn $"\nStackTrace ---\n{ex.StackTrace}"
    printfn $"\nTargetSite ---\n{ex.TargetSite}"

// This example of
//    Exception.Message,
//    Exception.HelpLink,
//    Exception.Source,
//    Exception.StackTrace, and
//    Exception.TargetSite
// generates the following output.

// Message ---
// The log table has overflowed. - Record "Log record number 5" was not logged.

// HelpLink ---
// https://learn.microsoft.com

// Source ---
// Exception_Class_Samples

// StackTrace ---
//    at NDP_UE_FS.LogTable.AddRecord(String newRecord)
//    at <StartupCode$fs>.$NDP_UE_FS.main@()

// TargetSite ---
// Int32 AddRecord(System.String)
' Example for the Exception.HelpLink, Exception.Source,
' Exception.StackTrace, and Exception.TargetSite properties.
Namespace NDP_UE_VB

    ' Derive an exception; the constructor sets the HelpLink and 
    ' Source properties.
    Class LogTableOverflowException
        Inherits Exception

        Private Const overflowMessage As String = _
            "The log table has overflowed."
           
        Public Sub New( auxMessage As String, inner As Exception )
            MyBase.New( String.Format( "{0} - {1}", _
                overflowMessage, auxMessage ), inner )

            Me.HelpLink = "https://learn.microsoft.com"
            Me.Source = "Exception_Class_Samples"

        End Sub
    End Class

    Class LogTable
       
        Public Sub New(numElements As Integer)
            logArea = New String(numElements) {}
            elemInUse = 0
        End Sub
           
        Protected logArea() As String
        Protected elemInUse As Integer
           
        ' The AddRecord method throws a derived exception if 
        ' the array bounds exception is caught.
        Public Function AddRecord( newRecord As String ) As Integer

            Try
                Dim curElement as Integer = elemInUse
                logArea( elemInUse ) = newRecord
                elemInUse += 1
                Return curElement

            Catch ex As Exception
                Throw New LogTableOverflowException( _
                    String.Format( "Record ""{0}"" was not logged.", _
                        newRecord ), ex )
            End Try
        End Function ' AddRecord
    End Class

    Module OverflowDemo
       
        ' Create a log table and force an overflow.
        Sub Main( )
            Dim log As New LogTable( 4 )
              
            Console.WriteLine( "This example of " & vbCrLf & _
                "   Exception.Message, " & vbCrLf & _
                "   Exception.HelpLink, " & vbCrLf & _
                "   Exception.Source, " & vbCrLf & _
                "   Exception.StackTrace, and " & vbCrLf & _
                "   Exception.TargetSite " & vbCrLf & _
                "generates the following output." )
              
            Try
                Dim count As Integer = 0
                 
                Do
                    log.AddRecord( _
                        String.Format( "Log record number {0}", count ) )
                    count += 1
                Loop

            Catch ex As Exception
                Console.WriteLine( vbCrLf & _
                    "Message ---" & vbCrLf & ex.Message )
                Console.WriteLine( vbCrLf & _
                    "HelpLink ---" & vbCrLf & ex.HelpLink )
                Console.WriteLine( vbCrLf & _
                    "Source ---" & vbCrLf & ex.Source )
                Console.WriteLine( vbCrLf & _
                    "StackTrace ---" & vbCrLf & ex.StackTrace )
                Console.WriteLine( vbCrLf & "TargetSite ---" & _
                    vbCrLf & ex.TargetSite.ToString( ) )
            End Try
        End Sub

    End Module ' OverflowDemo
End Namespace ' NDP_UE_VB

' This example of
'    Exception.Message,
'    Exception.HelpLink,
'    Exception.Source,
'    Exception.StackTrace, and
'    Exception.TargetSite
' generates the following output.
' 
' Message ---
' The log table has overflowed. - Record "Log record number 5" was not logged.
' 
' HelpLink ---
' https://learn.microsoft.com
' 
' Source ---
' Exception_Class_Samples
' 
' StackTrace ---
'    at NDP_UE_VB.LogTable.AddRecord(String newRecord)
'    at NDP_UE_VB.OverflowDemo.Main()
' 
' TargetSite ---
' Int32 AddRecord(System.String)

Commenti

Il valore restituito, che rappresenta un file della Guida, è un URN o URL. Ad esempio, il HelpLink valore potrebbe essere:

"file:///C:/Applications/Bazzal/help.html#ErrorNum42"

Si applica a