C#并行的Parallel.ForEach 和for循环的嵌套写入csv验证

目前这么些暂时没发现数据丢失问题，需要继续验证。

   string fullPath = @"C:\Users\cyan\Desktop\bbb.csv";
            FileStream fs = new FileStream(fullPath, System.IO.FileMode.Create, System.IO.FileAccess.Write);
            StreamWriter ObjWrites = default(StreamWriter);
            ObjWrites = new StreamWriter(fs,Encoding.Default);

//在如下双循环里面写入csv，涉及到多个线程共同写入，所以需要安全同步写入，否则会出现数据遗漏现象。
            dynamic swline = StreamWriter.Synchronized(ObjWrites);

   
 Parallel.ForEach(list2,i=>
            {
             
                string a1 = i.Name;
                double a2 = Convert.ToDouble(i.longa);
                double a3 = Convert.ToDouble(i.lata);
                foreach (var j in list)
                {
                    string b1 = j.Name;
                    double b2 = Convert.ToDouble(j.longa);
                    double b3 = Convert.ToDouble(j.lata);

                    if (a1 != b1)
                    {
                        double c1 = Distance(a2, a3, b2, b3);
                        if (c1 == 0)
                        {
                            string txt = string.Concat("并发：    ", ",", a1, ",", b1, ",", a2, ",", a3, ",", b2, ",", b3, ",", c1);
                            swline.WriteLine(txt);
                        }
                    }
                }                  
                  
            });