using System.Collections.Concurrent;
using NewLife.Collections;
using NewLife.Reflection;
using NewLife.Serialization;
#if NETCOREAPP
using System.Text.Json;
#endif
namespace System.Collections.Generic
{
/// <summary>集合扩展</summary>
public static class CollectionHelper
{
///// <summary>集合转为数组，加锁确保安全</summary>
///// <typeparam name="T"></typeparam>
///// <param name="collection"></param>
///// <param name="index">数组偏移量。大于0时，新数组将空出来前面一截，把数据拷贝到后面</param>
///// <returns></returns>
//[Obsolete("index参数晦涩难懂")]
//public static T[] ToArray<T>(this ICollection<T> collection, Int32 index)
//{
// if (collection == null) return null;
// lock (collection)
// {
// var count = collection.Count;
// if (count == 0) return Array.Empty<T>();
// var arr = new T[count + index];
// collection.CopyTo(arr, index);
// return arr;
// }
//}
/// <summary>集合转为数组，加锁确保安全</summary>
/// <typeparam name="T"></typeparam>
/// <param name="collection"></param>
/// <returns></returns>
public static T[] ToArray<T>(this ICollection<T> collection)
{
if (collection == null) return null;
lock (collection)
{
var count = collection.Count;
if (count == 0) return new T[0];
var arr = new T[count];
collection.CopyTo(arr, 0);
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>
/// <remarks>
/// 需要注意，还有一个 IExtend.ToDictionary() 扩展
/// </remarks>
/// <param name="target"></param>
/// <returns></returns>
public static IDictionary<String, Object> ToDictionary(this Object target)
{
//!! 即使传入为空，也返回字典，而不是null，避免业务层需要大量判空
//if (target == null) return null;
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;
}
}
#if NETCOREAPP
else if (target is JsonElement element && element.ValueKind == JsonValueKind.Object)
{
foreach (var item in element.EnumerateObject())
{
Object v = item.Value.ValueKind switch
{
JsonValueKind.Object => item.Value.ToDictionary(),
JsonValueKind.Array => ToArray(item.Value),
JsonValueKind.String => item.Value.GetString(),
JsonValueKind.Number when item.Value.GetRawText().Contains('.') => item.Value.GetDouble(),
JsonValueKind.Number => item.Value.GetInt64(),
JsonValueKind.True or JsonValueKind.False => item.Value.GetBoolean(),
_ => item.Value.GetString(),
};
if (v is Int64 n && n < Int32.MaxValue) v = (Int32)n;
dic[item.Name] = v;
}
}
#endif
else
{
foreach (var pi in target.GetType().GetProperties(true))
{
var name = SerialHelper.GetName(pi);
dic[name] = target.GetValue(pi);
}
}
}
return dic;
}
#if NETCOREAPP
static IList<Object> ToArray(JsonElement element)
{
var list = new List<Object>();
foreach (var item in element.EnumerateArray())
{
Object v = item.ValueKind switch
{
JsonValueKind.Object => item.ToDictionary(),
JsonValueKind.Array => ToArray(item),
JsonValueKind.String => item.GetString(),
JsonValueKind.Number when item.GetRawText().Contains('.') => item.GetDouble(),
JsonValueKind.Number => item.GetInt64(),
JsonValueKind.True or JsonValueKind.False => item.GetBoolean(),
_ => item.GetString(),
};
if (v is Int64 n && n < Int32.MaxValue) v = (Int32)n;
list.Add(v);
}
return list;
}
#endif
/// <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 dic;
return new NullableDictionary<TKey, TValue>(collection, comparer);
}
/// <summary>从队列里面获取指定个数元素</summary>
/// <typeparam name="T"></typeparam>
/// <param name="collection">消费集合</param>
/// <param name="count">元素个数</param>
/// <returns></returns>
public static IEnumerable<T> Take<T>(this Queue<T> collection, Int32 count)
{
if (collection == null) yield break;
while (count-- > 0 && collection.Count > 0)
{
yield return collection.Dequeue();
}
}
///// <summary>从消费集合里面获取指定个数元素</summary>
///// <typeparam name="T"></typeparam>
///// <param name="collection">消费集合</param>
///// <param name="count">元素个数</param>
///// <returns></returns>
//public static IEnumerable<T> Take<T>(this IProducerConsumerCollection<T> collection, Int32 count)
//{
// if (collection == null) yield break;
// while (count-- > 0 && collection.TryTake(out var item))
// {
// yield return item;
// }
//}
}
}
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