c# - 获取属性名称

Question

有没有办法获取传递给函数的值的属性名称？

Answer 1

你问这是否可能？

public void PrintPropertyName(int value) {
    Console.WriteLine(someMagicCodeThatPrintsThePropertyName);
}

// x is SomeClass having a property named SomeNumber
PrintInteger(x => x.SomeNumber);

和“SomeNumber”会打印到控制台吗？

如果是这样，不是。这显然是不可能的(提示:PrintPropertyName(5) 会发生什么？)。但你可以这样做:

public static string GetPropertyName<TSource, TProperty>(this Expression<Func<TSource, TProperty>> expression) {
    Contract.Requires<ArgumentNullException>(expression != null);
    Contract.Ensures(Contract.Result<string>() != null);
    PropertyInfo propertyInfo = GetPropertyInfo(expression);
    return propertyInfo.Name;
}

public static PropertyInfo GetPropertyInfo<TSource, TProperty>(this Expression<Func<TSource, TProperty>> expression) {
    Contract.Requires<ArgumentNullException>(expression != null);
    Contract.Ensures(Contract.Result<PropertyInfo>() != null);
    var memberExpression = expression.Body as MemberExpression;
    Guard.Against<ArgumentException>(memberExpression == null, "Expression does not represent a member expression.");
    var propertyInfo = memberExpression.Member as PropertyInfo;
    Guard.Against<ArgumentException>(propertyInfo == null, "Expression does not represent a property expression.");
    Type type = typeof(TSource);
    Guard.Against<ArgumentException>(type != propertyInfo.ReflectedType && type.IsSubclassOf(propertyInfo.ReflectedType));
    return propertyInfo;
}

用法:

string s = GetPropertyName((SomeClass x) => x.SomeNumber);
Console.WriteLine(s);

现在“SomeNumber”将打印到控制台。