A man told a woman alone that he found out he liked her, was he trying to pick her up or was he joking?

When you say this to a woman alone, you need to analyze the tone of his voice when he speaks. You also need to have a certain understanding of the man to know whether he is joking. If the man is usually more serious, If he is really steady, then he really likes that woman if he says this. If he is more frivolous, it is just a joke.