工作过程中，一些代码片段记录

缺乏、安全感 2022-08-08 00:58 204阅读 0赞

Random rd = new Random(Guid.NewGuid().GetHashCode());
    xxxlist.OrderBy(x = >rd.Next()).Take(n).ToList();

/// <summary>
    /// 记录JsonResult、ContentResult、JavaScriptResult三种ActionResult
    /// </summary>
    public class ResultFilterAttribute : FilterAttribute, IResultFilter
    {
        /// <summary>
        /// 保存post提交的参数
        /// </summary>
        public bool SavePost { get; set; }
        /// <summary>
        /// 
        /// </summary>
        /// <param name="filterContext"></param>
        public void OnResultExecuted(ResultExecutedContext filterContext)
        {
            var jsonResult = filterContext.Result as JsonResult;
            try
            {
                string content = string.Empty;
                JavaScriptSerializer jss = null;
                if (jsonResult != null)
                {
                    var data = jsonResult.Data;
                    jss = new JavaScriptSerializer();
    
                    content = jss.Serialize(data);
                }
                var contentResult = filterContext.Result as ContentResult;
                if (contentResult != null)
                {
                    content = contentResult.Content;
                }
    
                var javaScriptResult = filterContext.Result as JavaScriptResult;
                if (javaScriptResult != null)
                {
                    content = javaScriptResult.Script;
                }
                if (string.IsNullOrWhiteSpace(content))
                {
                    return;
                }
                string userName = filterContext.HttpContext.User.Identity.Name;
                string ip = Common.WebUtils.Get_ClientIP();
    
                string host = filterContext.HttpContext.Request.Url.Host;
                string url = filterContext.HttpContext.Request.Url.ToString();
                string browser = Common.WebUtils.GetClientBrowser();
                string urlReferrer = string.Empty;
                if (filterContext.HttpContext.Request.UrlReferrer != null)
                {
                    urlReferrer = filterContext.HttpContext.Request.UrlReferrer.ToString();
                }
    
                string form = string.Empty;
                if (SavePost)
                {
                    if (jss == null)
                        jss = new JavaScriptSerializer();
    
                    var keys = filterContext.HttpContext.Request.Form.AllKeys;
                    Dictionary<string, string> dic = new Dictionary<string, string>();
                    foreach (var key in keys)
                    {
                        dic[key] = filterContext.HttpContext.Request.Form[key];
                    }
                    form = jss.Serialize(dic);
                }
                HttpLog.Service.LogInfo_Insert(new HttpLog.Service.LogInfo
                {
                    Browser = browser,
                    CreateTime = DateTime.Now.Ticks,
                    Host = host,
                    IP = ip,
                    Url = url.ToLower(),
                    UrlReferrer = urlReferrer.ToLower(),
                    UserName = userName,
                    Content = content,
                    Form = form
                });
            }
            catch (Exception ex)
            {
                LogHelper.Error("记录httplog失败", ex);
            }
        }
    
        public void OnResultExecuting(ResultExecutingContext filterContext)
        {
            //........
        }
    }

string str = "xxxxxxxxxxxxxxxxxxx";
    string targetstr = "biaud.com";
    bool check = str.ToLower().IndexOf(targetstr, StringComparison.Ordinal) > -1;

对象是否在枚举项中定义

public enum enumStatus {
        All = 0,
        Started = 1,
        End = 2
    }
    bool enumDefine = Enum.IsDefined(typeof(enumStatus), 1); // or 
    bool enumDefine = Enum.IsDefined(typeof(enumStatus), "Started");

public static string Md5EncryptClassic(string plainText) {
        using(MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider()) {
            byte[] _byte = hashmd5.ComputeHash(Encoding.Default.GetBytes(plainText ? ?string.Empty));
            return System.BitConverter.ToString(_byte).Replace("-", "").ToLower();
        }
    }
    public static string HashEx(long userId) {
        string md = Md5EncryptClassic(userId.ToString());
        return md.Substring(0, 2).ToLower();
    }

public static string Serialize(object value) {
        if (value == null) {
            return null;
        }
        XmlSerializer xs = new XmlSerializer(value.GetType());
        StringBuilder sb = new StringBuilder();
        StringWriter sw = new StringWriter(sb);
        xs.Serialize(sw, value);
        Regex reg = new Regex(@"[\s]*xmlns:[\w]*?=""[\w\W]*?""");
        string temp = reg.Replace(sb.ToString(), string.Empty);
        Regex reg2 = new Regex(@"<[?]xml[\w\W]+?[?]>");
        temp = reg2.Replace(temp, string.Empty);
        temp = StringHelper.ClearSpecialChar(temp);
        // "<?xml version=\"1.0\" encoding=\"UTF-8\" ?>"
        return temp;
    }
    
    public static T Deserialize < T > (string xml) {
        try {
            if (!string.IsNullOrEmpty(xml)) {
                XmlSerializer xs;
                StringReader sr = new StringReader(xml);
                xs = new XmlSerializer(typeof(T));
                return (T) xs.Deserialize(sr);
            } else {
                return
            default (T);
            }
        } catch //(Exception ex)
        {
            return
        default (T);
        }
    }
    
    public class StringHelper {
        /// <summary>
        /// 清除特殊字符
        /// </summary>
        /// <param name="sourceString"></param>
        /// <returns></returns>
        public static string ClearSpecialChar(string sourceString) {
            string pattern = @"[\u0000-\u0008]|[\u000B-\u000C]|[\u000E-\u001F]";
            System.Text.RegularExpressions.Regex reg = new System.Text.RegularExpressions.Regex(pattern, System.Text.RegularExpressions.RegexOptions.IgnoreCase | System.Text.RegularExpressions.RegexOptions.Multiline);
    
            string temp = reg.Replace(sourceString, "");
            //&#x{0:X}; 
            return System.Text.RegularExpressions.Regex.Replace(temp, "&#x[0-9a-f]{1,6};", "", System.Text.RegularExpressions.RegexOptions.IgnoreCase);
        }
    }
    //eg:
    FreeProductExpand model = Deserialize < FreeProductExpand > (xmlstr);
    string anstr = model.Answer;

xxxBusinessDTO entity = new xxxBusinessDTO();
    var query = entity.GetType().GetProperties().Select(x = >x.Name).ToList();
    foreach(var item in query) {
        this.listBox1.Items.Add(item);
    }
    this.label1.Text = string.Format("类 xxxBusinessDTO 共{0}个字段", query.Count);
    
    //匹配
    var checkarr = checkstr.Split(','); //checkstr--->ID,ProductID,ProductPrice,...
    checkarr.ToList().ForEach(x = >{
        if (!query.Any(t = >t.ToString() == x.ToString())) {
            this.listBox2.Items.Add(x);
        }
    });

![SouthEast][]

object转byte\[\]：

private byte[] ObjectToByteArray(object obj)
            {
                if (obj == null)
                    return new byte[] { };
    
                var bf = new BinaryFormatter();
                using (var ms = new MemoryStream())
                {
                    bf.Serialize(ms, obj);
                    return ms.ToArray();
                }
            }

利用动态对象和反射，给属性赋值（简单的mapping）：

public class CCMapper<T> where T : class
        {
            //为了避免不同线程造成对静态字段更改的不可控事件发生 通常静态字段都使用readonly 表示初始化以后 就只读了 
            private static readonly Dictionary<string, PropertyInfo> PropertyMap;
            /// <summary>
            /// 静态构造函数只在类被调用的第一次启动 类似初始化的作用
            /// 静态构造函数不会建立一个实例 而是用于初始化函数本身的一些static的字段的
            /// 没有参数 也没有修饰符 
            /// </summary>
            static CCMapper() //静态够着函数只执行一次
            {
                PropertyMap = typeof(T).GetProperties().ToDictionary(p => p.Name.ToLower(), p => p);
            }
    
            public static void Map(System.Dynamic.ExpandoObject source, T destination)
            {
                if (source == null)
                    throw new ArgumentNullException("source");
                if (destination == null)
                    throw new ArgumentNullException("destination");
    
                foreach (var kv in source)
                {
                    PropertyInfo p;
                    if (PropertyMap.TryGetValue(kv.Key.ToLower(), out p))
                    {
                        var propType = p.PropertyType;
                        if (kv.Value == null)
                        {
                            if (!propType.IsByRef && propType.Name != "Nullable`1")
                            {
                                throw new ArgumentException("not nullable");
                            }
                        }
                        p.SetValue(destination, kv.Value == DBNull.Value ? default(T) : kv.Value, null);
                    }
                }
            }
        }

使用demo：

static void Main(string[] args)
            {
                DataTable dt = new DataTable();
                dt.Columns.AddRange(new DataColumn[]
                { 
                    new DataColumn("Name", typeof(string)),
                    new DataColumn("Address", typeof(string)),
                    new DataColumn("Score", typeof(int)),
                    new DataColumn("Brithday", typeof(DateTime))
                });
    
                DataRow dr = dt.NewRow();
                dr["Name"] = "jon";
                dr["Address"] = "浙江杭州";
                dr["Score"] = 70;
                dr["Brithday"] = new DateTime(1987, 9, 20);
                dt.Rows.Add(dr);
    
                dr = dt.NewRow();
                dr["Name"] = "joyhen";
                dr["Address"] = "文三西路";
                dr["Score"] = 58;
                dr["Brithday"] = DateTime.Now.AddYears(-20);
                dt.Rows.Add(dr);
    
                var objects = new List<dynamic>();
    
                foreach (DataRow row in dt.Rows)
                {
                    dynamic obj = new System.Dynamic.ExpandoObject();
    
                    foreach (DataColumn column in dt.Columns)
                    {
                        var x = (IDictionary<string, object>)obj;
                        x.Add(column.ColumnName, row[column.ColumnName]);
                    }
                    objects.Add(obj);
                }
    
                var retval = new List<Tb_Unser>();
                foreach (dynamic item in objects)
                {
                    var o = new Tb_Unser();
                    CCMapper<Tb_Unser>.Map(item, o);
                    retval.Add(o);
                }
    
                //return retval;
                var str = string.Join(",", retval.Select(x => x.Name).ToArray());
                Console.WriteLine(str);
            }

前面提到了ExpandObject，那么我们顺带一说mvc中的序列化，很简单，json.net就ok，这里用Contet输出

public ActionResult Data() 
    { 
        dynamic expando = new ExpandoObject(); 
        expando.name = "Jon Skeet"; 
        expando.age = 46;
    
        var json = JsonConvert.SerializeObject(expando);
        return Content(json, "application/json"); 
    }

获取枚举项目集合：

string[] itemsarr = Enum.GetNames(typeof(PropertyType)); //枚举集合

PropertyType是枚举对象

Json.net时间格式处理：

/// <summary>
        /// 序列化、反序列化 处理类
        /// </summary>
        /// <typeparam name="T"></typeparam>
        public class JsonUtils
        {
            private static readonly IsoDateTimeConverter _timeFormat;
            static JsonUtils()
            {
                _timeFormat = _timeFormat = new IsoDateTimeConverter()
                {
                    DateTimeFormat = "yyyy-MM-dd HH:mm:ss"
                };
            }
    
            /// <summary>
            /// 序列化
            /// </summary>
            public static string JsonSerializer(object obj)
            {
                //return JsonConvert.SerializeObject(obj, Formatting.None, new JsonSerializerSettings()
                return JsonConvert.SerializeObject(obj, Formatting.Indented, new JsonSerializerSettings()
                {
                    ContractResolver = new CamelCasePropertyNamesContractResolver(),
                    Converters = new JsonConverter[1] { _timeFormat }
                });
            }
    
            /// <summary>
            /// 反序列化
            /// </summary>
            public static T DeserializeObject<T>(string str)
            {
                if (string.IsNullOrEmpty(str)) return default(T);
                return JsonConvert.DeserializeObject<T>(str);
            }
        }

class CoolMother
            {
                public static Func<CoolMother> Activator { get; protected set; }
    
                //防止空引用
                static CoolMother()
                {
                    Activator = () => new CoolMother();
                }
    
                public CoolMother()
                {
                    Message = "I am the mother";
                }
    
                public string Message { get; protected set; }
            }
    
            class HotDaughter : CoolMother
            {
                public HotDaughter()
                {
                    Activator = () => new HotDaughter();
                    Message = "I am the daughter";
                }
            }

测试调用：

Console.WriteLine(HotDaughter.Activator().Message); //触发几类的静态构造函数
    var create = new HotDaughter(); //重写了基类的Activator和Message
    Console.WriteLine(HotDaughter.Activator().Message);

I am the mother  
I am the daughter

GZip压缩：

public static class CompressionHelper
            {
                /// <summary> 
                /// Compress the byte[] 
                /// </summary> 
                /// <param name="input"></param> 
                /// <returns></returns> 
                public static byte[] Compress(byte[] input)
                {
                    byte[] output;
                    using (MemoryStream ms = new MemoryStream())
                    {
                        using (GZipStream gs = new GZipStream(ms, CompressionMode.Compress))
                        {
                            gs.Write(input, 0, input.Length);
                            gs.Close();
                            output = ms.ToArray();
                        }
                        ms.Close();
                    }
                    return output;
                }
    
                /// <summary> 
                /// Decompress the byte[] 
                /// </summary> 
                /// <param name="input"></param> 
                /// <returns></returns> 
                public static byte[] Decompress(byte[] input)
                {
                    List<byte> output = new List<byte>();
                    using (MemoryStream ms = new MemoryStream(input))
                    {
                        using (GZipStream gs = new GZipStream(ms, CompressionMode.Decompress))
                        {
                            int readByte = gs.ReadByte();
                            while (readByte != -1)
                            {
                                output.Add((byte)readByte);
                                readByte = gs.ReadByte();
                            }
                            gs.Close();
                        }
                        ms.Close();
                    }
                    return output.ToArray();
                }
            }

Using classic ADO.NET in ASP.NET 5： [http://blog.developers.ba/using-classic-ado-net-in-asp-net-vnext/][http_blog.developers.ba_using-classic-ado-net-in-asp-net-vnext]

[SouthEast]: /images/20220805/ebeed768e2f54aa0be24226b7a665297.png
[http_blog.developers.ba_using-classic-ado-net-in-asp-net-vnext]: http://blog.developers.ba/using-classic-ado-net-in-asp-net-vnext/