using System.Collections.Concurrent;
using System.Reflection;
using System.Xml.Serialization;
using NewLife.Collections;
using NewLife.Reflection;
namespace System.Collections.Generic
{
/// <summary>集合扩展</summary>
public static class CollectionHelper
{
/// <summary>集合转为数组</summary>
/// <typeparam name="T"></typeparam>
/// <param name="collection"></param>
/// <param name="index"></param>
/// <returns></returns>
public static T[] ToArray<T>(this ICollection<T> collection, Int32 index = 0)
{
if (collection == null) return null;
var count = collection.Count;
if (count == 0) return new T[0];
lock (collection)
{
count = collection.Count;
if (count == 0) return new T[0];
var arr = new T[count - index];
collection.CopyTo(arr, index);
return arr;
}
}
/// <summary>集合转为数组</summary>
/// <typeparam name="TKey"></typeparam>
/// <typeparam name="TValue"></typeparam>
/// <param name="collection"></param>
/// <param name="index"></param>
/// <returns></returns>
public static IList<TKey> ToKeyArray<TKey, TValue>(this IDictionary<TKey, TValue> collection, Int32 index = 0)
{
if (collection == null) return null;
if (collection is ConcurrentDictionary<TKey, TValue> cdiv) return cdiv.Keys as IList<TKey>;
if (collection.Count == 0) return new TKey[0];
lock (collection)
{
var arr = new TKey[collection.Count - index];
collection.Keys.CopyTo(arr, index);
return arr;
}
}
/// <summary>集合转为数组</summary>
/// <typeparam name="TKey"></typeparam>
/// <typeparam name="TValue"></typeparam>
/// <param name="collection"></param>
/// <param name="index"></param>
/// <returns></returns>
public static IList<TValue> ToValueArray<TKey, TValue>(this IDictionary<TKey, TValue> collection, Int32 index = 0)
{
if (collection == null) return null;
if (collection is ConcurrentDictionary<TKey, TValue> cdiv) return cdiv.Values as IList<TValue>;
if (collection.Count == 0) return new TValue[0];
lock (collection)
{
var arr = new TValue[collection.Count - index];
collection.Values.CopyTo(arr, index);
return arr;
}
}
/// <summary>目标匿名参数对象转为字典</summary>
/// <param name="target"></param>
/// <returns></returns>
public static IDictionary<String, Object> ToDictionary(this Object target)
{
if (target is IDictionary<String, Object> dic) return dic;
dic = new NullableDictionary<String, Object>(StringComparer.OrdinalIgnoreCase);
if (target != null)
{
// 修正字符串字典的支持问题
if (target is IDictionary dic2)
{
foreach (DictionaryEntry item in dic2)
{
dic[item.Key + ""] = item.Value;
}
}
else
{
foreach (var pi in target.GetType().GetProperties())
{
if (pi.GetIndexParameters().Length > 0) continue;
if (pi.GetCustomAttribute<XmlIgnoreAttribute>() != null) continue;
dic[pi.Name] = target.GetValue(pi);
}
}
}
return dic;
}
/// <summary>合并字典参数</summary>
/// <param name="dic">字典</param>
/// <param name="target">目标对象</param>
/// <param name="overwrite">是否覆盖同名参数</param>
/// <param name="excludes">排除项</param>
/// <returns></returns>
public static IDictionary<String, Object> Merge(this IDictionary<String, Object> dic, Object target, Boolean overwrite = true, String[] excludes = null)
{
var exs = excludes != null ? new HashSet<String>(StringComparer.OrdinalIgnoreCase) : null;
foreach (var item in target.ToDictionary())
{
if (exs == null || !exs.Contains(item.Key))
{
if (overwrite || !dic.ContainsKey(item.Key)) dic[item.Key] = item.Value;
}
}
return dic;
}
/// <summary>转为可空字典</summary>
/// <typeparam name="TKey"></typeparam>
/// <typeparam name="TValue"></typeparam>
/// <param name="collection"></param>
/// <param name="comparer"></param>
/// <returns></returns>
public static IDictionary<TKey, TValue> ToNullable<TKey, TValue>(this IDictionary<TKey, TValue> collection, IEqualityComparer<TKey> comparer = null)
{
if (collection == null) return null;
if (collection is NullableDictionary<TKey, TValue> dic && (comparer != null || dic.Comparer == comparer)) return collection as NullableDictionary<TKey, TValue>;
return new NullableDictionary<TKey, TValue>(collection, comparer);
}
}
}
|