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- using System.Collections;
- using System.Text;
- namespace PlcSiemens.Core.Extension
- {
- /// <summary>集合扩展</summary>
- public static class CollectionExtension
- {
- /// <summary>
- /// 确保某一类型的元素必须位于开始位置
- /// </summary>
- /// <typeparam name="T"></typeparam>
- /// <param name="source"></param>
- /// <param name="checkedItem">想要位于首位的元素的类型</param>
- /// <returns>调整后的集合</returns>
- /// <remarks>
- /// 本方法适用于要确认的元素的类型在集合中唯一的情况。
- /// </remarks>
- public static void EnsureFirstPosition<T>(this IEnumerable<T> source, Type checkedItem)
- {
- if (source == null)
- {
- return;
- }
- var sourceArray = new List<T>(source);
- var itemIndex = sourceArray.FindIndex(m => m.GetType() == checkedItem);
- if (itemIndex <= 0) return;
- var changeItem = sourceArray[itemIndex];
- sourceArray.RemoveAt(itemIndex);
- sourceArray.Insert(0, changeItem);
- source = sourceArray;
- }
- /// <summary>
- /// 确保某一类型的元素必须位于末尾位置
- /// </summary>
- /// <typeparam name="T"></typeparam>
- /// <param name="source"></param>
- /// <param name="checkedItem">想要位于首位的元素的类型</param>
- /// <returns>调整后的集合</returns>
- /// <remarks>
- /// 本方法适用于要确认的元素的类型在集合中唯一的情况。
- /// </remarks>
- public static void EnsureLastPosition<T>(this IEnumerable<T> source, Type checkedItem)
- {
- if (source == null)
- {
- return;
- }
- var sourceArray = new List<T>(source);
- var itemIndex = sourceArray.FindIndex(m => m.GetType() == checkedItem);
- if (itemIndex == sourceArray.Count - 1) return;
- var changeItem = sourceArray[itemIndex];
- sourceArray.RemoveAt(itemIndex);
- sourceArray.Insert(sourceArray.Count - 1, changeItem);
- source = sourceArray;
- }
- /// <summary>
- /// 集合转换
- /// </summary>
- /// <typeparam name="T">对象类型</typeparam>
- /// <typeparam name="TResult">转换后的对象</typeparam>
- /// <param name="items">对象</param>
- /// <param name="transformation">转换表达式</param>
- /// <returns></returns>
- public static IEnumerable<TResult> ConvertAll<T, TResult>(this IEnumerable<T> items,
- Converter<T, TResult> transformation)
- {
- if (items == null) return null;
- var arr = items as T[];
- if (arr != null)
- {
- return Array.ConvertAll(arr, transformation);
- }
- var list = items as List<T>;
- if (list != null)
- {
- return list.ConvertAll(transformation);
- }
- return items.Select(_ => transformation(_));
- }
- /// <summary>
- /// Func转Predicate
- /// </summary>
- /// <typeparam name="T"></typeparam>
- /// <param name="source"></param>
- /// <returns></returns>
- public static Predicate<T> ToPredicate<T>(this Func<T, bool> source)
- {
- var result = new Predicate<T>(source);
- return result;
- }
- /// <summary>
- /// IEnumerable<T>对象的轮询操作
- /// </summary>
- /// <typeparam name="T"></typeparam>
- /// <param name="items"></param>
- /// <param name="action"></param>
- public static void ForEach<T>(this IEnumerable<T> items, Action<T> action)
- {
- if (items == null)
- {
- return;
- }
- var arr = items as T[];
- if (arr != null)
- {
- Array.ForEach(arr, action);
- return;
- }
- var list = items as List<T>;
- if (list != null)
- {
- list.ForEach(action);
- return;
- }
- foreach (var item in items)
- {
- action(item);
- }
- }
- /// <summary>
- /// IEnumerable<T>是否为空
- /// </summary>
- /// <param name="targer"></param>
- /// <returns></returns>
- public static bool IsNullOrEmpty(this IEnumerable targer)
- {
- return targer == null || targer.GetEnumerator().MoveNext() == false;
- }
- /// <summary>
- /// ICollection<T />转换成数组T[]
- /// </summary>
- public static T[] ToArray<T>(this ICollection<T> collection, int index = 0)
- {
- if (collection.IsNullOrEmpty()) return null;
- var arr = new T[collection.Count];
- collection.CopyTo(arr, index);
- return arr;
- }
- /// <summary>把一个列表组合成为一个字符串,默认逗号分隔</summary>
- /// <param name="value"></param>
- /// <param name="separator">组合分隔符,默认逗号</param>
- /// <returns></returns>
- public static string Join(this IEnumerable value, string separator = ",")
- {
- if (value == null) return null;
- var sb = new StringBuilder();
- foreach (var item in value)
- {
- sb.Separate(separator).Append(item + "");
- }
- return sb.ToString();
- }
- /// <summary>把一个列表组合成为一个字符串,默认逗号分隔</summary>
- /// <param name="value"></param>
- /// <param name="separator">组合分隔符,默认逗号</param>
- /// <param name="func">把对象转为字符串的委托</param>
- /// <returns></returns>
- public static string Join<T>(this IEnumerable<T> value, string separator = ",", Func<T, string> func = null)
- {
- if (value == null) return null;
- var sb = new StringBuilder();
- if (func == null) func = obj => obj + "";
- foreach (var item in value)
- {
- sb.Separate(separator).Append(func(item));
- }
- return sb.ToString();
- }
- /// <summary>
- /// 在考虑依赖关系的情况下,使用托普法进行排序
- /// </summary>
- /// <typeparam name="T">要排序的类型.</typeparam>
- /// <param name="source">要排序的数据</param>
- /// <param name="getDependencies">依赖项查询</param>
- /// <returns></returns>
- public static List<T> SortByDependencies<T>(this IEnumerable<T> source, Func<T, IEnumerable<T>> getDependencies)
- {
- var sorted = new List<T>();
- var visited = new Dictionary<T, bool>();
- foreach (var item in source)
- {
- SortByDependenciesVisit(item, getDependencies, sorted, visited);
- }
- return sorted;
- }
- private static void SortByDependenciesVisit<T>(T item, Func<T, IEnumerable<T>> getDependencies, List<T> sorted, Dictionary<T, bool> visited)
- {
- bool inProcess;
- var alreadyVisited = visited.TryGetValue(item, out inProcess);
- if (alreadyVisited)
- {
- if (inProcess)
- {
- throw new ArgumentException("Cyclic dependency found!");
- }
- }
- else
- {
- visited[item] = true;
- var dependencies = getDependencies(item);
- if (dependencies != null)
- {
- foreach (var dependency in dependencies)
- {
- SortByDependenciesVisit(dependency, getDependencies, sorted, visited);
- }
- }
- visited[item] = false;
- sorted.Add(item);
- }
- }
- }
- }
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