C#公共帮助类 Convert帮助类
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大家知道，开发项目除了数据访问层很重要外，就是Common了，这里就提供了强大且实用的工具。
一、DataTable
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Data; using System.Reflection; using System.Collections; namespace Common { public partial class DataTable { /// <summary> /// 转换 DataTable 对象为 IList 对象 /// </summary> /// <param name="datas">数据集合</param> /// <returns>数组对象</returns> public static T[] ToArray<T>(DataTable datas) where T : class, new() { List<T> list = ToList<T>(datas) as List<T>; return list.ToArray(); } /// <summary> /// 转换IList对象为DataTable对象 /// </summary> /// <param name="datas">数据集合</param> /// <returns>DataTable对象</returns> public static DataTable ToDataTable<T>(IList<T> datas) { return ToDataTable<T>(datas, null); } /// <summary> /// 转换IList对象为DataTable对象 /// </summary> /// <param name="datas">数据集合</param> /// <returns>DataTable对象</returns> public static DataTable ToDataTable<T>(T[] datas) { return ToDataTable<T>(datas, null); } /// <summary> /// 转换IList对象为DataTable对象 /// </summary> /// <param name="datas">数据集合</param> /// <param name="tableName">要创建的表名</param> /// <returns>DataTable对象</returns> public static DataTable ToDataTable<T>(IList<T> datas, string tableName) { Type type = typeof(T); if (string.IsNullOrEmpty(tableName)) { tableName = type.Name; } DataTable table = new DataTable(tableName); table.BeginLoadData(); PropertyInfo[] properties = type.GetProperties(BindingFlags.Public | BindingFlags.Instance); foreach (PropertyInfo info in properties) { string typeName = info.PropertyType.ToString(); if (info.PropertyType.IsGenericType) { typeName = info.PropertyType.GetGenericArguments()[0].ToString(); } Type type2 = Type.GetType(typeName, false); if (type2 != null) { table.Columns.Add(info.Name, type2); } } if ((datas != null) && (datas.Count > 0)) { foreach (object obj2 in datas) { DataRow row = table.NewRow(); foreach (PropertyInfo info2 in properties) { if ((Type.GetType(info2.PropertyType.ToString(), false) != null) && (info2.GetValue(obj2, null) != null)) { row[info2.Name] = info2.GetValue(obj2, null); } } table.Rows.Add(row); } } table.EndLoadData(); table.AcceptChanges(); return table; } public static DataTable ListToDataTable(object datas, string tableName) { Type type = ZGeneric.GetGenericType(datas); if (string.IsNullOrEmpty(tableName)) tableName = type.Name; DataTable table = new DataTable(tableName); table.BeginLoadData(); var properties = ZReflection.GetProperties(type); foreach (var p in properties) { Type colType = p.Value.PropertyType; string typeName = colType.ToString(); if (colType.IsGenericType) typeName = colType.GetGenericArguments()[0].ToString(); Type newType = Type.GetType(typeName, false); if (newType != null) table.Columns.Add(p.Value.Name, newType); } IEnumerator enumerator = ((dynamic)datas).GetEnumerator(); while (enumerator.MoveNext()) { DataRow row = table.NewRow(); foreach (var p in properties) { var value = ZGeneric.GetValue(enumerator.Current, p.Value.Name); if ((Type.GetType(p.Value.PropertyType.ToString(), false) != null) && (value != null)) row[p.Value.Name] = value; } table.Rows.Add(row); } table.EndLoadData(); table.AcceptChanges(); return table; } /// <summary> /// 转换IList对象为DataTable对象 /// </summary> /// <param name="datas">数据集合</param> /// <param name="tableName">要创建的表名</param> /// <returns>DataTable对象</returns> public static DataTable ToDataTable<T>(T[] datas, string tableName) { IList<T> list; if ((datas == null) || (datas.Length == 0)) { list = new List<T>(); } else { list = new List<T>(datas); } return ToDataTable<T>(list, tableName); } /// <summary> /// 转换 DataTable 对象为 IList 对象 /// </summary> /// <param name="datas">数据集合</param> /// <returns>IList 对象</returns> public static IList<T> ToList<T>(DataTable datas) where T : class, new() { IList<T> list = new List<T>(); if ((datas != null) && (datas.Rows.Count != 0)) { PropertyInfo[] properties = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance); foreach (DataRow row in datas.Rows) { T local = Activator.CreateInstance<T>(); foreach (DataColumn column in datas.Columns) { object obj2 = null; if (row.RowState == DataRowState.Deleted) { obj2 = row[column, DataRowVersion.Original]; } else { obj2 = row[column]; } if (obj2 != DBNull.Value) { foreach (PropertyInfo info in properties) { if (column.ColumnName.Equals(info.Name, StringComparison.CurrentCultureIgnoreCase)) { info.SetValue(local, obj2, null); } } } } list.Add(local); } } return list; } } }
二、Enum
public static T ToEnum<T>(object obj, T defaultEnum) { string str = To<string>(obj); if (Enum.IsDefined(typeof(T),str)) return (T)Enum.Parse(typeof(T),str); int num; if (int.TryParse(str, out num)) { if (Enum.IsDefined(typeof(T), num)) return (T)Enum.ToObject(typeof(T), num); } return defaultEnum; }
三、Generics
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Collections.Specialized; using System.Reflection; namespace Common { public partial class Generics { /// <summary> /// 转换object为 T 值 /// </summary> /// <typeparam name="T">T 类型</typeparam> /// <param name="obj">要被转换的值</param> /// <returns>T 类型值</returns> public static T To<T>(object obj) { return To<T>(obj, default(T)); } /// <summary> /// 转换object为 T 值 /// </summary> /// <typeparam name="T">T 类型</typeparam> /// <param name="obj">要被转换的值</param> /// <returns>T 类型值</returns> public static T To<T>(object obj,T defaultValue) { if (obj==null) { return defaultValue; } else if (obj is T) { return (T)obj; } else { try { Type conversionType = typeof(T); object obj2 = null; if (conversionType.Equals(typeof(Guid))) obj2 = new Guid(Convert.ToString(obj)); else obj2 = Convert.ChangeType(obj, conversionType); return (T)obj2; } catch (Exception) { return defaultValue; } } } /// <summary> /// 填充客户端提交的值到 T 对象 如appinfo = AppConvert.To<Appinfo>(context.Request.Form); /// </summary> /// <typeparam name="T">T 类</typeparam> /// <param name="datas">客户端提交的值</param> /// <returns>T 对象</returns> public static T To<T>(NameValueCollection datas) where T : class, new() { Type type = typeof(T); string[] strArray = type.FullName.Split(new char[] { \'.\' }); string str = strArray[strArray.Length - 1]; PropertyInfo[] properties = type.GetProperties(BindingFlags.Public | BindingFlags.Instance); T local = Activator.CreateInstance<T>(); foreach (string str2 in datas.AllKeys) { string str3 = datas[str2]; if (!string.IsNullOrEmpty(str3)) { str3 = str3.TrimEnd(new char[0]); } foreach (PropertyInfo info in properties) { string str4 = string.Format("{0}.{1}", str, info.Name); if (str2.Equals(info.Name, StringComparison.CurrentCultureIgnoreCase) || str2.Equals(str4, StringComparison.CurrentCultureIgnoreCase)) { string typeName = info.PropertyType.ToString(); if (info.PropertyType.IsGenericType) { typeName = info.PropertyType.GetGenericArguments()[0].ToString(); } object nullInternal = GetNullInternal(info.PropertyType); Type conversionType = Type.GetType(typeName, false); if (!string.IsNullOrEmpty(str3)) { nullInternal = Convert.ChangeType(str3, conversionType); } info.SetValue(local, nullInternal, null); } } } return local; } #region 获取类型的默认值 //另一种获取默认值的方法 private static object GetDefaultValue(Type type) { object value = null; if (type.IsValueType) value = Activator.CreateInstance(type); else value = null; return value; } // 获取指定类型的默认值.引用类型(包含String)的默认值为null private static T DefaultValue<T>() { return default(T); } //获取默认值 private static object GetNullInternal(Type type) { if (type.IsValueType) { if (type.IsEnum) { return GetNullInternal(Enum.GetUnderlyingType(type)); } if (type.IsPrimitive) { if (type == typeof(int)) { return 0; } if (type == typeof(double)) { return 0.0; } if (type == typeof(short)) { return (short)0; } if (type == typeof(sbyte)) { return (sbyte)0; } if (type == typeof(long)) { return 0L; } if (type == typeof(byte)) { return (byte)0; } if (type == typeof(ushort)) { return (ushort)0; } if (type == typeof(uint)) { return 0; } if (type == typeof(ulong)) { return (ulong)0L; } if (type == typeof(ulong)) { return (ulong)0L; } if (type == typeof(float)) { return 0f; } if (type == typeof(bool)) { return false; } if (type == typeof(char)) { return \'\\0\'; } } else { if (type == typeof(DateTime)) { return DateTime.MinValue; } if (type == typeof(decimal)) { return 0M; } if (type == typeof(Guid)) { return Guid.Empty; } if (type == typeof(TimeSpan)) { return new TimeSpan(0, 0, 0); } } } return null; } #endregion } }
四、String
/// <summary> /// 转换为string类型 defult为string.Empty /// </summary> /// <param name="obj"></param> /// <returns></returns> public static string ToString(object obj) { return To<string>(obj,string.Empty); }
五、TreeData
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Dynamic; namespace Common { public partial class TreeData { public static List<dynamic> ListToTreeData<T>(List<T> source, string ID, string PID) where T : class, new() { Action<List<dynamic>, T, dynamic> AddItem = (parent, item, Recursive) => { var childrens = new List<dynamic>(); var thisitem = ZGeneric.GetDictionaryValues(item); source.FindAll(o => ZGeneric.GetValue(item, ID).Equals(ZGeneric.GetValue(o, PID))) .ForEach(subitem => { Recursive(childrens, subitem, Recursive); }); thisitem.Add("children", childrens); parent.Add(thisitem); }; var target = new List<dynamic>(); source.FindAll(m => { return !source.Exists(n => ZGeneric.GetValue(n, ID).Equals(ZGeneric.GetValue(m, PID))); }) .ForEach(item => AddItem(target, item, AddItem)); return target; } public static List<T> TreeDataToList<T>(List<dynamic> source) { Action<List<dynamic>, List<T>, dynamic> AddItem = (mysource, mytarget, Recursive) => { foreach (var oldrow in mysource) { var newrow = ZGeneric.CreateNew<T>(); var dictionary = (IDictionary<string, object>)ZGeneric.GetDictionaryValues(oldrow); var childern = dictionary["childern"] as List<dynamic>; if (childern.Count > 0) Recursive(mysource, mytarget, Recursive); foreach (var property in dictionary) if (property.Key != "children") ZGeneric.SetValue(newrow, property.Key, property.Value); mytarget.Add(newrow); } }; var target = new List<T>(); AddItem(source, target, AddItem); return target; } } }
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