83 lines
3.7 KiB
C#
83 lines
3.7 KiB
C#
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using System;
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using System.Collections.Generic;
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using System.ComponentModel;
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namespace JiShe.CollectBus.Common.Extensions
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{
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/// <summary>
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/// Extension methods for Dictionary.
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/// </summary>
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public static class DictionaryExtensions
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{
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/// <summary>
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/// This method is used to try to get a value in a dictionary if it does exists.
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/// </summary>
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/// <typeparam name="T">Type of the value</typeparam>
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/// <param name="dictionary">The collection object</param>
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/// <param name="key">Key</param>
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/// <param name="value">Value of the key (or default value if key not exists)</param>
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/// <returns>True if key does exists in the dictionary</returns>
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internal static bool TryGetValue<T>(this IDictionary<string, object> dictionary, string key, out T value)
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{
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object valueObj;
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if (dictionary.TryGetValue(key, out valueObj) && valueObj is T)
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{
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value = (T)valueObj;
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return true;
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}
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value = default(T);
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return false;
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}
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/// <summary>
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/// Gets a value from the dictionary with given key. Returns default value if can not find.
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/// </summary>
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/// <param name="dictionary">Dictionary to check and get</param>
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/// <param name="key">Key to find the value</param>
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/// <typeparam name="TKey">Type of the key</typeparam>
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/// <typeparam name="TValue">Type of the value</typeparam>
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/// <returns>Value if found, default if can not found.</returns>
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[Description("从字典中获取具有给定键的值，如果找不到，则返回默认值")]
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public static TValue GetOrDefault<TKey, TValue>(this IDictionary<TKey, TValue> dictionary, TKey key)
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{
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TValue obj;
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return dictionary.TryGetValue(key, out obj) ? obj : default(TValue);
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}
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/// <summary>
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/// Gets a value from the dictionary with given key. Add value if can not find.
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/// </summary>
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/// <param name="dictionary">Dictionary to check and get</param>
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/// <param name="key">Key to find the value</param>
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/// <param name="factory">A factory method used to create the value if not found in the dictionary</param>
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/// <typeparam name="TKey">Type of the key</typeparam>
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/// <typeparam name="TValue">Type of the value</typeparam>
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/// <returns>Value if found, default if can not found.</returns>
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[Description("从字典中获取具有给定键的值，如果找不到，则添加")]
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public static TValue GetOrAdd<TKey, TValue>(this IDictionary<TKey, TValue> dictionary, TKey key, Func<TKey, TValue> factory)
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{
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TValue obj;
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if (dictionary.TryGetValue(key, out obj))
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{
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return obj;
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}
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return dictionary[key] = factory(key);
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}
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/// <summary>
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/// Gets a value from the dictionary with given key. Add value if can not find.
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/// </summary>
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/// <param name="dictionary">Dictionary to check and get</param>
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/// <param name="key">Key to find the value</param>
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/// <param name="factory">A factory method used to create the value if not found in the dictionary</param>
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/// <typeparam name="TKey">Type of the key</typeparam>
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/// <typeparam name="TValue">Type of the value</typeparam>
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/// <returns>Value if found, default if can not found.</returns>
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public static TValue GetOrAdd<TKey, TValue>(this IDictionary<TKey, TValue> dictionary, TKey key, Func<TValue> factory)
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{
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return dictionary.GetOrAdd(key, k => factory());
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}
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}
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}
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