using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;

namespace ConsoleApplication2
{
    class Program
    {
        static void Main(string[] args)
        {
            string fn = @"1.dxf";
            ReadDxf rd = new ReadDxf(fn);
            ArrayList abc = new ArrayList();
            abc=rd.ReadPolyline(@"0");

            double[,] ps=new double[abc.Count,2];
            for (int i = 0; i < abc.Count; i++)
            {
                double[] ds = new double[2];
                ds = (double[])abc[i];
                ps[i, 0] = ds[0]; ps[i, 1] = ds[1];


                WriteToFile wtf = new WriteToFile(@"1.txt");
                string[] str = new string[2];
                str[0] = ps[0, 0].ToString("F3");
                str[1] = ps[0, 1].ToString("F3");
                wtf.WriteStringByLine(str);
                wtf.Close();
            }

            

                     
        }
    }
}
（ReadDxf为引用的类）

不懂啊

     WriteToFile wtf = new WriteToFile(@"1.txt");
                string[] str = new string[2];
                str[0] = ps[0, 0].ToString("F3");
                str[1] = ps[0, 1].ToString("F3");
                wtf.WriteStringByLine(str);
                wtf.Close();

这段代码不要放进for循环内部 当然只能存一个了
放到循环外部 等都读取完放到数组里 你在遍历数组 ps 内容在存到文件

好的，我试一下