通过变量引用属性名称 [英] Refer to a property name by variable

问题描述

是否可以使用变量来引用属性名称?

Is there a way to refer to a property name with a variable?

场景:对象A具有公共整数属性X和Z，所以...

Scenario: Object A have public integer property X an Z, so...

public void setProperty(int index, int value)
{
    string property = "";

    if (index == 1)
    {
        // set the property X with 'value'
        property = "X";
    }
    else 
    {
        // set the property Z with 'value'
        property = "Z";
    }

    A.{property} = value;
}

这是一个愚蠢的例子，所以请相信，我对此很有用.

This is a silly example so please believe, I have an use for this.

推荐答案

简单:

a.GetType().GetProperty("X").SetValue(a, value);

请注意，如果 a 的类型没有名为"X"的属性，则 GetProperty("X")返回 null .

Note that GetProperty("X") returns null if type of a has no property named "X".

要使用您提供的语法设置属性，只需编写一个扩展方法:

To set property in the syntax you have provided just write an extension method:

public static class Extensions
{
    public static void SetProperty(this object obj, string propertyName, object value)
    {
        var propertyInfo = obj.GetType().GetProperty(propertyName);
        if (propertyInfo == null) return;
        propertyInfo.SetValue(obj, value);
    }
}

并像这样使用它:

a.SetProperty(propertyName, value);

UPD

请注意，这种基于反射的方法相对较慢.为了获得更好的性能，请使用动态代码生成或表达式树.有很好的库可以为您完成这些复杂的工作.例如， FastMember .

Note that this reflection-based method is relatively slow. For better performance use dynamic code generation or expression trees. There are good libraries that can do this complex stuff for you. For example, FastMember.

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