性能难题：PropertyInfo属性的读取为什么哪么慢？？？

2008-07-08 10:11:23 146 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

C#反射PropertyInfo实战：动态获取属性信息与性能优化指南反射是.NET框架中实现运行时类型检查和动态操作的核心机制，它允许程序在编译后获取和操作类型元数据。其原理基于System.Type类作为类型入口，通过PropertyInfo等元数据对象实现属性的动态读写。这项技术的核心价值在于提升代码的灵活性和通用性，尤其在数据映射、序列化、通用工具开发等场景中不可或缺。然而，反射操作也伴随着显著的性能开销，因此缓存PropertyInfo对象、使用预编译委托等优化策略至关重要。本文聚焦于C#开发中的PropertyInfo应用，深入探讨如何高效获取属性名称与值，并结合阅读详情

性能难题：PropertyInfo属性的读取为什么哪么慢？？？

下面的程序调用ProcessProperties函数可以返回某个对象的属性与值字串，用来作为对象缓存的关键词，
但是发现这个读属性的过程速度难以接受。用单元测试竟然要15.625毫秒。晕。

究竟如何改进才能提高速度呢？头疼。。。。向各位高手求教了。。。。谢谢。。。。

public class CacheKey
{
private static Type typeCacheKeyAttr = typeof(CacheKeyAttribute);

/// <summary>
/// 处理属性
/// </summary>
/// <param name="baseObject"></param>
/// <returns></returns>
private static string ProcessProperties(object baseObject)
{
// 读取对象属性数组集合
PropertyInfo[] properties = baseObject.GetType().GetProperties(BindingFlags.Instance | BindingFlags.Public);
System.Collections.Generic.List<string> cachekeys = new System.Collections.Generic.List<string>();

// 遍历属性数组
foreach (PropertyInfo pi in properties)
{
cachekeys.Add(string.Format("{0}:{1}", KeyName(pi), pi.GetValue(baseObject, null)));
}

return string.Join("-", (string[])cachekeys.ToArray());
}

/// <summary>
/// 关键词名称
/// </summary>
/// <param name="mi"></param>
/// <returns></returns>
private static string KeyName(MemberInfo mi)
{
if (mi.IsDefined(typeCacheKeyAttr, true))
return ((CacheKeyAttribute)mi.GetCustomAttributes(typeCacheKeyAttr, true)[0]).KeyName;
else
return mi.Name;
}
}

/// <summary>
/// 缓存关键词特性类（特性类型都直接或间接地从 Attribute 类派生）
/// 注：类引这里的特性类名时可以用全名，也可以前缀名称都可以正常工作；
/// Indicates the property should be part of the cache key if set and other than the default value
/// </summary>
[AttributeUsage(AttributeTargets.Field | AttributeTargets.Property)]
public class CacheKeyAttribute : System.Attribute
{
/// <summary>
/// String to use in place of the property or field name in the cache key creation
/// </summary>
/// <param name="keyName"></param>
public CacheKeyAttribute(string keyName)
{
KeyName = keyName;
Ignored = false;
HasDefaultValue = false;
}

/// <summary>
/// String to use in place of the property or field name in the cache key creation Only non default values will be included in the final key
/// </summary>
/// <param name="keyName"></param>
/// <param name="defaultValue"></param>
public CacheKeyAttribute(string keyName, object defaultValue)
{
KeyName = keyName;
DefaultValue = defaultValue;
HasDefaultValue = true;
Ignored = false;
}

/// <summary>
/// Always ingore this field or property in cache key generation if set to true (no need to set this to true if other constructors are used)
/// </summary>
/// <param name="includeInKey"></param>
public CacheKeyAttribute(bool includeInKey)
{
Ignored = !includeInKey;
HasDefaultValue = false;
}

public readonly string KeyName;
public readonly object DefaultValue;
public readonly bool HasDefaultValue;
public readonly bool Ignored;
}

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