32 lines
966 B
C#
32 lines
966 B
C#
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using System;
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using System.Collections.Generic;
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using System.Linq.Expressions;
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public static class InstanceFactory
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{
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private static readonly Dictionary<Type, Func<object>> _constructorCache = new();
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public static object CreateInstanceOptimized(Type type)
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{
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if (!_constructorCache.TryGetValue(type, out var constructor))
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{
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// 验证是否存在公共无参构造函数
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var ctor = type.GetConstructor(Type.EmptyTypes);
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if (ctor == null)
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{
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throw new MissingMethodException($"类型 {type.Name} 缺少公共无参构造函数");
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}
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// 构建表达式树：new T()
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var newExpr = Expression.New(ctor);
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var lambda = Expression.Lambda<Func<object>>(newExpr);
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constructor = lambda.Compile();
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// 缓存委托
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_constructorCache[type] = constructor;
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}
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return constructor();
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}
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}
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