Exception.HelpLink Property

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

Property Value

The Uniform Resource Name (URN) or Uniform Resource Locator (URL).

Implements

Examples

The following code example throws an Exception that sets the HelpLink property in its constructor and then catches the exception and displays HelpLink.

// 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)

Remarks

The return value, which represents a help file, is a URN or URL. For example, the HelpLink value could be:

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