怎么一次性删除结构体 List 中满足条件某值的所有元素？

  for (int i = 0; i < mdownPoint.Count; i++)//此for语句是放在button控件button1_Click事件中的
            {
                if (mdownPoint[i].C== 1)
                {
                    mdownPoint.RemoveAt(i);
                }
            }

using System;
using System.Collections.Generic;
using using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication7
{
    public struct Path
        {
            public  int A;
            public int B;
            public int C;
        }


    public partial class Form1 : Form
    {
        List<Path> mdownPoint = new List<Path>() {};
        public Form1()
        {
            InitializeComponent();
            this.Load += new EventHandler(Form1_Load);
        }

        void Form1_Load(object sender, EventArgs e)
        {
            Path p = new Path();
            p.A = 1;
            p.B = 0;
            p.C = 1;
            mdownPoint.Add(p);

            Path p1 = new Path();
            p1.A = 0;
            p1.B = 3;
            p1.C = 1;
            mdownPoint.Add(p1);

            Path p2 = new Path();
            p2.A = 2;
            p2.B = 0;
            p2.C = 1;
            mdownPoint.Add(p2);

            Path p3 = new Path();
            p3.A = 5;
            p3.B = 8;
            p3.C = 1;
            mdownPoint.Add(p3);

        }

      

        private void button1_Click(object sender, EventArgs e)
        {
            op(mdownPoint.Count);
            int a = mdownPoint.Count;//此处可以下断点监视查看一下删除的结果是否正确
        }


        private void op(int ccount)//ccount 是mdownPoint.Count的数量
        {
            for (int i = 0; i < ccount; i++)//此for语句是放在button控件button1_Click事件中的
            {

                if (mdownPoint[i].C == 1)
                {
                    mdownPoint.RemoveAt(i);
                    op(mdownPoint.Count);
                    break;
                }
            }
        }

    }
}