使用LINQ，如何转换IList <IList<object> &gt;至IList <object> ？

Question

I'm trying to convert a IList<IList<object>> to IList<object> , I mean to have a unique and one list where contains all the element (object) of the first one.

    public IList<IList<Page>> PMTs
    {
        get
        {
            var pmts = Processes.Select(x => x.PageMapTable)
                                .ToList();
            return pmts;
        }
    }

    public IList<Page> BlockMapTable
    {
        get
        {
            // Incomplete
            var btm = PMTs.Select(x => x.?? ..
        }
    }

Answer 1

Assuming that you want to flatMap/flatten the list<list<Page>> , you can do that with selectMany method, like so:

public IList<Page> BlockMapTable
{
    get
    {
        var btm = PMTs.SelectMany(x => x).ToList();
    }
}

if you want to read more about it, here is a great blog post about selectMany extension method

Answer 2

public IList<Page> BlockMapTable
    {
        get
        {
            return PMTs.SelectMany(p => p).ToList();
        }
    }