c# - 缩短此反射属性名称辅助方法？

Question

我想要一个静态辅助方法来删除魔法字符串。当然，我可以将属性方法打包到 TestContainer 中，这样就无需提供 TestContainer 作为参数。这做得很好 here .

但我希望在一个静态类中包含辅助方法，以防我以后决定优化我的代码并删除该方法。我设法把它归结为这个，但它有点难看(必须提供字符串类型，看起来不太好)。

任何知道更好方法的“表达神”。请记住，静态类应该保持通用并且不知道任何关于 TestContainer 的信息(否则它会像提供的链接一样简单)

internal class PropertyNameResolving
{
    internal class TestContainer
    {
        public string LastName { get; set; }
    }

    internal static class BindingHelper
    {
        public static string PropertyName<TObject, TValue>(Expression<Func<TObject, TValue>> propertySelector)
        {
            var memberExpression = propertySelector.Body as MemberExpression;
            if (memberExpression != null) return memberExpression.Member.Name;
            else
            throw new Exception("Something went wrong");
        }
    }

    internal static void Test()
    {
        var t = new TestContainer {LastName = "Hans"};
        Console.WriteLine(BindingHelper.PropertyName<TestContainer, string>(x => x.LastName));
        Console.ReadLine();

    }
}

顺便说一句，输出是“LastName”，可用于设置绑定(bind)。

还有一个问题，我可以安全地删除 NULL 检查吗？

Answer 1

3 种选择:

• 使类通用，并在方法上使用推断来获取值
• 使用示例对象来推断方法
• 完全忘记对象类型，只用一个例子

这些都显示在下面。关于 null 安全性——我很想检查表达式类型(顺便说一句，你也可以处理方法)——更多代码 shown here .

using System;
using System.Linq.Expressions;
internal class TestContainer
{
    public string LastName { get; set; }
}
static class Program
{
    static void Main()
    {
        var t = new TestContainer {LastName = "Hans"};            
        string s1 = BindingHelper<TestContainer>
                      .PropertyName(x => x.LastName);            
        string s2 = BindingHelper.PropertyName(t, x => x.LastName);
        string s3 = BindingHelper.PropertyName(() => t.LastName);
    }
}
internal static class BindingHelper
{
    public static string PropertyName<TObject, TValue>(TObject template,
        Expression<Func<TObject, TValue>> propertySelector)
    {
        var memberExpression = propertySelector.Body as MemberExpression;
        if (memberExpression != null) return memberExpression.Member.Name;
        else
            throw new Exception("Something went wrong");
    }
    public static string PropertyName<TValue>(
         Expression<Func<TValue>> propertySelector)
    {
        var memberExpression = propertySelector.Body as MemberExpression;
        if (memberExpression != null) return memberExpression.Member.Name;
        else
            throw new Exception("Something went wrong");
    }
}
internal static class BindingHelper<TObject>
{
    public static string PropertyName<TValue>(
        Expression<Func<TObject, TValue>> propertySelector)
    {
        var memberExpression = propertySelector.Body as MemberExpression;
        if (memberExpression != null) return memberExpression.Member.Name;
        else
            throw new Exception("Something went wrong");
    }
}