Barley Salad

1 pound barley, rinsed well, cooked until tender. 1, 15oz. can cooked black beans, rinsed 1 pound frozen sweet corn, steamed or air fried and cooled 1 medium red onion, sliced thin 1/4 chopped fresh dill 1/4 chopped parsley 2 cups red wine vinegar 1 cup brown sugar...