Return type of Exception StackTrace

Question

Hi I am writing C# codes from legacy VB Codes, I have a function:

Public Shared Sub logError(ByVal ex As Exception, ByVal additionalInfo As String) 
    Dim messagestr As String
    If ex.StackTrace.Length > 0 Then
        For Each stackTrace As String In ex.StackTrace
             messagestr &= stackTrace
        Next
    End If

I converted the for loop as:

foreach (string stackTrace in ex.StackTrace)
{
      messagestr += stackTrace;
}

There is an error message under 'foreach': "Cannot convert type 'char' to 'string'.

It's quite weird as I read the StackTrace from MSDN that it returns a string. So I don't know why there is a for loop in the legacy VB codes. Also, I don't where the 'char' comes from.

I think I am complete lost in this area. Can anybody help me out?

Answer 1

The return type of ex.StackTrace is a string. The object that you will get by iterating over a string is char not another string. So you foreach loop must be:

foreach (char stackTrace in ex.StackTrace)
{

}

Or simply append stack trace to your string:

messagestr += ex.StackTrace;

If you want to get all function calls separately use this code to split your string into lines:

var stackLines = ex.StackTrace.Split('\n')

Answer 2

According to the documentation StackTrace Gets a string representation of the immediate frames on the call stack.

So when you iterate a string which will actually iterate through its characters, this is happening in your case.

Where as in VB it Represents a stack trace, which is an ordered collection of one or more stack frames. so when you iterate it iterates through the frames