Question

如何将以下嵌套foreach循环转换为Linq表达式？

由于

        List<Plan> plans = new List<Plan>();

        foreach (var planning in plannings)
        {
            foreach (var plan in planning)
            {
                plans.Add(plan);
            }                
        }

我希望看到它与lambda表达式（.Select()）完成比from .. select语法更多，如果可能的话

Answer 1

var plans = plannings.SelectMany(p => p);

Answer 2

List<Plan> plans = plannings.SelectMany(ps => ps).ToList();

Answer 3

为了完整起见，这是查询语法版本：

var query = from planning in plannings
            from plan in planning
            select plan;

List<Plan> plans = query.ToList();

Answer 4

        List<Plan> plans = new List<Plan>();

        foreach (var plan in plans.SelectMany(planning => planning))
        {
            newPlans.Add(plan as Plan);
        }

..可能有用！

Linq打开了一个嵌套的foreach

4 个答案: