Logging Method Name in C#

logMessage("functionName",  "something bad happened");

Yes the above works if IF *if* you remember to update "functionName". However, remembering to update the parameter after copying from another method is often not done. It is also a pain and not necessary. A little reflection easily solves this problem:

// start one up so that we don't get the current
// method but the one that called this one
StackFrame sf = new StackFrame(1, true);
System.Reflection.MethodBase mb = sf.GetMethod();
string methodName = mb != null ? mb.Name : "";
// fileName can be null, if unable to determine
string fileName = sf.GetFileName();
// we only want the filename not the complete path
if (fileName != null) fileName = fileName.Substring(fileName.LastIndexOf('\\') + 1);
int lineNumber = sf.GetFileLineNumber();

However the above does not work if you are using RichException or other proxies. So something a bit more complicated is needed:

private StackFrame GetCallingStackFrame()
{
    // Determine the method that called the one that is calling this one.
    // This is not just two up the Stack because of RichException support.
    StackFrame sf = null;
    // Start at 2.  1 for this one and another for the one above that.
    StackTrace st = new StackTrace(2, true);
    Type thisType = GetType();
    foreach (StackFrame sfi in st.GetFrames())
    {
        // Find a calling method that is not part of this log class but is part
        // of the same Namespace.
        Type callType = sfi.GetMethod().DeclaringType;
        if (callType != thisType &&
            callType.Namespace == thisType.Namespace &&
            !callType.IsInterface)
        {
            sf = sfi;
            break;
        }
    }
    return sf;
}

This can then be used like so:

StackFrame sf = GetCallingStackFrame();
if (sf != null) // if found add info to log message
{
    System.Reflection.MethodBase mb = sf.GetMethod();
    string methodName = mb != null ? mb.Name : "";
    string fileName = sf.GetFileName();
    if (fileName != null) fileName = fileName.Substring(fileName.LastIndexOf('\\') + 1);
    int lineNumber = sf.GetFileLineNumber();

    if (fileName != null)
    {
         strMsg = fileName + "(" + lineNumber + ") - " + methodName + " - " + strMsg;
    }
    else
    {
         strMsg = "unknown - " + methodName + " - " + strMsg;
    }
}