c# - Generic logging of function parameters in exception handling

Question

A lot of my C# code follows this pattern:

void foo(string param1, string param2, string param3)
{
    try
    {
         // do something...
    }
    catch(Exception ex)
    {
        LogError(String.Format("Error in foo(param1={0}, param2={1}, param3={2}), exception={3}", param1, param2, param3, ex.Message));
    }
}

Is there a way in .NET to get a Key/Value list of the parameters to a function so that I can call another function to construct my error logging string? OR Do you have a more generic / better way of doing this?

Answer 1

You could use Reflection and the convention that you must pass the parameters to the LogError with the right order:

private static void MyMethod(string s, int x, int y)
{
    try
    {
        throw new NotImplementedException();
    }
    catch (Exception ex)
    {
        LogError(MethodBase.GetCurrentMethod(), ex, s, x, y);
    }
}

private static void LogError(MethodBase method, Exception ex, params object[] values)
{
    ParameterInfo[] parms = method.GetParameters();
    object[] namevalues = new object[2 * parms.Length];

    string msg = "Error in " + method.Name + "(";
    for (int i = 0, j = 0; i < parms.Length; i++, j += 2)
    {
        msg += "{" + j + "}={" + (j + 1) + "}, ";
        namevalues[j] = parms[i].Name;
        if (i < values.Length) namevalues[j + 1] = values[i];
    }
    msg += "exception=" + ex.Message + ")";
    Console.WriteLine(string.Format(msg, namevalues));
}