从对象获取属性信息不给属性名作为字符串 [英] Get Property Info from an object without giving the property name as string
问题描述
对于一些原因,我需要建立相应的一些类的属性(我们称之为的PropertyInfo
实例的字典 EntityClass
)。
好吧,我可以使用 typeof运算(entityClass)方法.GetProperties()
。
但我还需要确定某些特定属性的值(在编译时已知)。
通常我可以做下列之一:
EntityInstance.PropertyX =值;
typeof运算(entityClass)方法.GetProperty(PropertyX)的SetValue(EntityInstance,值null)。
为了填补我的字典里,我需要使用的PropertyInfo
实例,而不仅仅是通常设定值。但我不觉得其字符串名称舒适获取属性。如果某些EntityClass变化,这会带来许多例外,而不是编译错误。所以,我想问的是:
如何获得一个知名物业公司的PropertyInfo没有通过字符串名称?
如果有什么东西,就像代表我会爱:
SomeDelegateType MyDelegate = EntityInstance.MethodX;
在理想情况下:
SomePropertyDelegate MyPropertyDelegate = EntityInstance.PropertyX;
这样呢?
字符串s = getPropertyName方法<使用者>(X => x.Name);
公共字符串getPropertyName方法< T>(表达式来; Func键< T,对象>>拉姆达)
{
VAR成员= lambda.Body为MemberExpression;
VAR道具= member.Member为的PropertyInfo;
返回prop.Name;
}
或
公开的PropertyInfo为getPropertyInfo< T>(表达式来; Func键< T,对象>>拉姆达)
{
VAR成员= lambda.Body为MemberExpression;
返回member.Member为的PropertyInfo;
}
公共类用户
{
公共字符串名称{设置;得到; }
}
For some reasons, I need to create a Dictionary of PropertyInfo
instances corresponding to some class' properties (let's call it EntityClass
).
Ok, I could use typeof(EntityClass).GetProperties()
.
But I also need to determine a value for some specific properties (known at compile time). Normally I could do one of the following:
EntityInstance.PropertyX = Value;
typeof(EntityClass).GetProperty("PropertyX").SetValue(EntityInstance, Value, null);
In order to fill up my dictionary, I need to use PropertyInfo
instances instead of just setting the values normally. But I don't feel confortable getting properties by their string names. If some EntityClass changes, it would bring many exceptions instead of compile errors. So, what I ask is:
How to get a known property's PropertyInfo without passing the string name? I would love if there's something just like delegates:
SomeDelegateType MyDelegate = EntityInstance.MethodX;
Ideally:
SomePropertyDelegate MyPropertyDelegate = EntityInstance.PropertyX;
Something like this?
string s = GetPropertyName<User>( x=> x.Name );
public string GetPropertyName<T>(Expression<Func<T, object>> lambda)
{
var member = lambda.Body as MemberExpression;
var prop = member.Member as PropertyInfo;
return prop.Name;
}
or
public PropertyInfo GetPropertyInfo<T>(Expression<Func<T, object>> lambda)
{
var member = lambda.Body as MemberExpression;
return member.Member as PropertyInfo;
}
public class User
{
public string Name { set; get; }
}
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