Imports System
Imports System.Diagnostics
Imports SampleInternal
Namespace SamplePublic
' This console application illustrates various uses
' of the StackTrace and StackFrame classes.
Class ConsoleApp
<STAThread()> _
Shared Sub Main()
Dim mainClass As New ClassLevel1
Try
mainClass.InternalMethod()
Catch
Console.WriteLine(" Main method exception handler")
' Display file and line information, if available.
Dim st As New StackTrace(New StackFrame(True))
Console.WriteLine(" Stack trace for current level: {0}", _
st.ToString())
Console.WriteLine(" File: {0}", _
st.GetFrame(0).GetFileName())
Console.WriteLine(" Line Number: {0}", _
st.GetFrame(0).GetFileLineNumber().ToString())
Console.WriteLine()
Console.WriteLine("-------------------------------------------------")
Console.WriteLine()
End Try
End Sub 'Main
End Class 'ConsoleApp
End Namespace 'StackFramePublic
Namespace SampleInternal
Public Class ClassLevel1
Public Sub InternalMethod()
Try
Dim nestedClass As New ClassLevel2
nestedClass.Level2Method()
Catch e As Exception
Console.WriteLine(" InternalMethod exception handler")
' Build a stack trace from one frame, skipping the
' current frame and using the next frame. By default,
' file and line information are not displayed.
Dim st As New StackTrace(New StackFrame(1))
Console.WriteLine(" Stack trace for next level frame: {0}", _
st.ToString())
Console.WriteLine(" Stack frame for next level: ")
Console.WriteLine(" {0}", st.GetFrame(0).ToString())
Console.WriteLine(" Line Number: {0}", _
st.GetFrame(0).GetFileLineNumber().ToString())
Console.WriteLine()
Console.WriteLine(" ... throwing exception to next level ...")
Console.WriteLine("-------------------------------------------------")
Console.WriteLine()
Throw e
End Try
End Sub 'InternalMethod
End Class 'ClassLevel1
Public Class ClassLevel2
Public Sub Level2Method()
Try
Dim nestedClass As New ClassLevel3
nestedClass.Level3Method()
Catch e As Exception
Console.WriteLine(" Level2Method exception handler")
' Display the full call stack at this level.
Dim st1 As New StackTrace(True)
Console.WriteLine(" Stack trace for this level: {0}", _
st1.ToString())
' Build a stack trace from one frame, skipping the current
' frame and using the next frame.
Dim st2 As New StackTrace(New StackFrame(1, True))
Console.WriteLine(" Stack trace built with next level frame: {0}", _
st2.ToString())
' Build a stack trace skipping the current frame, and
' including all the other frames.
Dim st3 As New StackTrace(1, True)
Console.WriteLine(" Stack trace built from the next level up: {0}", _
st3.ToString())
Console.WriteLine()
Console.WriteLine(" ... throwing exception to next level ...")
Console.WriteLine("-------------------------------------------------")
Console.WriteLine()
Throw e
End Try
End Sub 'Level2Method
End Class 'ClassLevel2
Public Class ClassLevel3
Public Sub Level3Method()
Try
Dim nestedClass As New ClassLevel4()
nestedClass.Level4Method()
Catch e As Exception
Console.WriteLine(" Level3Method exception handler")
' Build a stack trace from a dummy stack frame.
' Explicitly specify the source file name and line number.
Dim st As New StackTrace(New StackFrame("source.cs", 60))
Console.WriteLine(" Stack trace with dummy stack frame: {0}", _
st.ToString())
Dim i As Integer
For i = 0 To st.FrameCount - 1
' Display the stack frame properties.
Dim sf As StackFrame = st.GetFrame(i)
Console.WriteLine(" File: {0}", sf.GetFileName())
Console.WriteLine(" Line Number: {0}", _
sf.GetFileLineNumber())
' The column number defaults to zero when not initialized.
Console.WriteLine(" Column Number: {0}", _
sf.GetFileColumnNumber())
If sf.GetILOffset <> StackFrame.OFFSET_UNKNOWN
Console.WriteLine(" Intermediate Language Offset: {0}", _
sf.GetILOffset())
End If
If sf.GetNativeOffset <> StackFrame.OFFSET_UNKNOWN
Console.WriteLine(" Native Offset: {0}", _
sf.GetNativeOffset())
End If
Next i
Console.WriteLine()
Console.WriteLine(" ... throwing exception to next level ...")
Console.WriteLine("-------------------------------------------------")
Console.WriteLine()
Throw e
End Try
End Sub 'Level3Method
End Class 'ClassLevel3
Public Class ClassLevel4
Public Sub Level4Method()
Try
Dim [nestedClass] As New ClassLevel5()
[nestedClass].Level5Method()
Catch e As Exception
Console.WriteLine(" Level4Method exception handler")
' Build a stack trace from a dummy stack frame.
' Explicitly specify the source file name, line number
' and column number.
Dim st As New StackTrace(New StackFrame("source.cs", 79, 24))
Console.WriteLine(" Stack trace with dummy stack frame: {0}", _
st.ToString())
' Access the StackFrames explicitly to display the file
' name, line number and column number properties.
' StackTrace.ToString only includes the method name.
Dim i As Integer
For i = 0 To st.FrameCount - 1
Dim sf As StackFrame = st.GetFrame(i)
Console.WriteLine(" File: {0}", sf.GetFileName())
Console.WriteLine(" Line Number: {0}", _
sf.GetFileLineNumber())
Console.WriteLine(" Column Number: {0}", _
sf.GetFileColumnNumber())
Next i
Console.WriteLine()
Console.WriteLine(" ... throwing exception to next level ...")
Console.WriteLine("-------------------------------------------------")
Console.WriteLine()
Throw e
End Try
End Sub 'Level4Method
End Class 'ClassLevel4
Public Class ClassLevel5
Public Sub Level5Method()
Try
Dim nestedClass As New ClassLevel6()
nestedClass.Level6Method()
Catch e As Exception
Console.WriteLine(" Level5Method exception handler")
Dim st As New StackTrace()
' Display the most recent function call.
Dim sf As StackFrame = st.GetFrame(0)
Console.WriteLine()
Console.WriteLine(" Exception in method: ")
Console.WriteLine(" {0}", sf.GetMethod())
If st.FrameCount > 1 Then
' Display the highest-level function call in the trace.
sf = st.GetFrame((st.FrameCount - 1))
Console.WriteLine(" Original function call at top of call stack):")
Console.WriteLine(" {0}", sf.GetMethod())
End If
Console.WriteLine()
Console.WriteLine(" ... throwing exception to next level ...")
Console.WriteLine("-------------------------------------------------")
Console.WriteLine()
Throw e
End Try
End Sub 'Level5Method
End Class 'ClassLevel5
Public Class ClassLevel6
Public Sub Level6Method()
Throw New Exception("An error occurred in the lowest internal class method.")
End Sub 'Level6Method
End Class 'ClassLevel6
End Namespace 'StackFrameInternal