Attach StackTrace To Exception Without Throwing in C# / .NET

Just create your own Exception type and override the StackTrace property:

class MyException : Exception
{
    private string oldStackTrace;

    public MyException(string message, string stackTrace) : base(message)
    {
        this.oldStackTrace = stackTrace;
    }


    public override string StackTrace
    {
        get
        {
            return this.oldStackTrace;
        }
    }
}

Well with nothing elegant available, here is my reflection based approach.

public static class ExceptionUtilities
{
    private static readonly FieldInfo STACK_TRACE_STRING_FI = typeof(Exception).GetField("_stackTraceString", BindingFlags.NonPublic | BindingFlags.Instance);
    private static readonly Type TRACE_FORMAT_TI = Type.GetType("System.Diagnostics.StackTrace").GetNestedType("TraceFormat", BindingFlags.NonPublic);
    private static readonly MethodInfo TRACE_TO_STRING_MI = typeof(StackTrace).GetMethod("ToString", BindingFlags.NonPublic | BindingFlags.Instance, null, new[] { TRACE_FORMAT_TI }, null);

    public static Exception SetStackTrace(this Exception target, StackTrace stack)
    {
        var getStackTraceString = TRACE_TO_STRING_MI.Invoke(stack, new object[] { Enum.GetValues(TRACE_FORMAT_TI).GetValue(0) });
        STACK_TRACE_STRING_FI.SetValue(target, getStackTraceString);
        return target;
    }
}

Writing a formatted StackTrace string to the _stackTraceString property seems to be enough to fool visual studio test runner and the Exception.ToString() methods into believing the stack was generated by a throw (without actually throwing anything).

See below for usage:

    StackTrace GetDeeperStackTrace(int depth)
    {
        if (depth > 0)
        {
            return GetDeeperStackTrace(depth - 1);
        }
        else
        {
            return new StackTrace(0, true);
        }
    }

    [TestMethod]
    public void Test007()
    {
        Exception needStackTrace = new Exception("Some exception");
        var st = GetDeeperStackTrace(3);

        needStackTrace.SetStackTrace(st);

        Trace.Write(needStackTrace.ToString());

        throw new Exception("Nested has custom stack trace", needStackTrace);
    }

You can use: Environment.StackTrace to capture the stacktrace at the occurence of the error in the component and then return it together with the other error informations or rethrow.

You can manually build stackframes to create a full trace. See StackFrame/StackTrace for more information.