CollectionExtensions.cs
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using NCC.Dependency;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace NCC.Common.Collections
{
/// <summary>
/// 集合扩展方法
/// </summary>
[SuppressSniffer]
public static class CollectionExtensions
{
/// <summary>
/// 如果条件成立，添加项
/// </summary>
public static void AddIf<T>(this ICollection<T> collection, T value, bool flag)
{
if (flag)
{
collection.Add(value);
}
}
/// <summary>
/// 如果条件成立，添加项
/// </summary>
public static void AddIf<T>(this ICollection<T> collection, T value, Func<bool> func)
{
if (func())
{
collection.Add(value);
}
}
/// <summary>
/// 如果不存在，添加项
/// </summary>
public static void AddIfNotExist<T>(this ICollection<T> collection, T value, Func<T, bool> existFunc = null)
{
bool exists = existFunc == null ? collection.Contains(value) : collection.Any(existFunc);
if (!exists)
{
collection.Add(value);
}
}
/// <summary>
/// 如果不为空，添加项
/// </summary>
public static void AddIfNotNull<T>(this ICollection<T> collection, T value) where T : class
{
if (value != null)
{
collection.Add(value);
}
}
/// <summary>
/// 获取对象，不存在对使用委托添加对象
/// </summary>
public static T GetOrAdd<T>(this ICollection<T> collection, Func<T, bool> selector, Func<T> factory)
{
T item = collection.FirstOrDefault(selector);
if (item == null)
{
item = factory();
collection.Add(item);
}
return item;
}
/// <summary>
/// 判断集合是否为null或空集合
/// </summary>
public static bool IsNullOrEmpty<T>(this ICollection<T> collection)
{
return collection == null || collection.Count == 0;
}
/// <summary>
/// 交换两项的位置
/// </summary>
public static void Swap<T>(this List<T> list, int index1, int index2)
{
if (index1 == index2)
{
return;
}
T tmp = list[index1];
list[index1] = list[index2];
list[index2] = tmp;
}
}
}