CODEWITHSUNDEEP
c#
user1108948
user1108948

Reputation:

Override a method in the third party

I have a third party party class say Log. It contains the methods

public void Write(string s, params object[] args)
{
            Monitor.Enter(this);
            try
            {
                            string logEntry = string.Format(s, args);
                            this.Write(logEntry);
            }
            finally
            {
                            Monitor.Exit(this);
            }
}

And

public void Write(string LogEntry)
{
    this.Write(0, LogEntry);
}

I defined a property outLog in my own class

public static Log OutLog  {get;set;}

I want to use the feature "CallerMemberNameAttribute" etc. in .net 4.5 and override the Write method as something like:

public void Write(string s,
    [CallerMemberName] string memberName = "",
    [CallerFilePath] string sourceFilePath = "",
    [CallerLineNumber] int sourceLineNumber = 0)
    {
        Monitor.Enter(this);
        try
        {
            string logEntry = string.Format(s, memberName, sourceFilePath, sourceLineNumber);
            this.Write(logEntry);
        }
        finally
        {
            Monitor.Exit(this);
        }
    }

So I can call it in my class:

outLog.Write(...);

Not sure how?

Upvotes: 0

Views: 1440

Answers (2)

svick
svick

Reputation: 244928

You can't override it, but you can create an extension method (which is signified by the this keyword on its first parameter) that will do what you want. Something like:

public static class LogExtensions
{
    public static void WriteWithCallerInfo(
        this Log log,
        string s,
        [CallerMemberName] string memberName = "",
        [CallerFilePath] string sourceFilePath = "",
        [CallerLineNumber] int sourceLineNumber = 0)
    {
        Monitor.Enter(log);
        try
        {
            string logEntry = string.Format(s, memberName, sourceFilePath, sourceLineNumber);
            log.Write(logEntry);
        }
        finally
        {
            Monitor.Exit(log);
        }
    }
}

With this, you can then write:

OutLog.WriteWithCallerInfo("whatever");

The extension method can't be called just Write, because normal methods take precedence over extension methods.

Note that I also don't understand the reason for the locking, I think it shouldn't be necessary, assuming the overload Write(int, string) is thread-safe.

Upvotes: 4

Paulo Morgado
Paulo Morgado

Reputation: 14856

You cannot override non virtual/abstract members.

You can hide but that will only work as long as you use the instance as being an instance of your class. If you use it as being an instance of the base class, it will call the base classe's method.

Upvotes: -1

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