Trade.dll 股票交易接口C#调用源代码

Trade.dll 股票交易接口C#调用源代码
http://www.nezip.cn/forum.php?mod=viewthread&tid=9&fromuid=1
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using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Runtime.InteropServices;
using System.IO;
using System.Threading;
using System.Windows.Forms;
using System.Collections.Specialized;
using System.Web;
using System.Net.Sockets;
using static System.Net.Mime.MediaTypeNames;

//总体说明：调用很简单，载入dll→发出指令→等待结果→解析结果

namespace TradeCS
{
    class CTest
    {
        [DllImport("Trade.dll")]
        private extern static int Start(RcvCallback_ callBack, IntPtr answer, int maxLen); //注册回调函数

        [DllImport("Trade.dll")]
        public extern static int Ask([MarshalAs(UnmanagedType.LPTStr)] string ask, IntPtr answer, int maxLen); //发出指令，参数参考调用规范填写，比如 下单?请求=登录&券商=信达证券
        [DllImport("Trade.dll")]
        private extern static int Stop();   //注销

        [UnmanagedFunctionPointerAttribute(CallingConvention.StdCall, CharSet = CharSet.Unicode)]
        public delegate int RcvCallback_(IntPtr ans, IntPtr data, int len, IntPtr dataEx, int exLen);  //定义回调函数对应的委托

        public static RcvCallback_ m_callBack = null;

        public static TcpC m_tdx = null;

        public static CTest s_test  = new CTest();
        //回调函数占用内部线程，为防止锁死，禁用运行耗时严重任务或进行界面操作。
        public static int Answer(IntPtr ans,  IntPtr data, int len, IntPtr dataEx, int exLen)
        {
            String query = KV_BASE.String(ans, "请求");
            String pkName = KV_BASE.String(ans, "包名称");
            String err = KV_BASE.String(ans, "错误");
            String kind = KV_BASE.Kind(ans);
            int td = KV_BASE.Int(ans, "通道");
            if (err.Length > 0)