我无法在C#7.0中通过反射从valuetuple获取参数名称 [英] I can't get parameter names from valuetuple via reflection in c# 7.0
问题描述
我想使用反射将ValueTuple映射到一个类。
文档说ValueTuple附加了一个带有参数名称的属性(Item1,Item2等除外),但我看不到任何属性。
反汇编什么都没有显示。
会发生什么事?
示例:
公共静态T ToStruct< T,T1,T2>(此ValueTuple< T1,T2>元组)其中T:结构
通过反射无法通过反射使Item1,Item2名称与T字段匹配。
您应在编译器创建的方法上具有 TupleElementNames
属性。
请参见< a href = https://tryroslyn.azurewebsites.net/#K4Zwlgdg5gBAygTxAFwKYFsDcBYAUAB2ACMAbMAYxnJIEMQQYBhGAbzxg5kNIpgApIyGDQA0MQTCIBKGAFk+Mtrk4qY7VRwBObEAB> m pre> public class C {
public(int a,int b)M(){
return(1,2);
}
}
编译为:
[返回:TupleElementNames(新字符串[] {
a,
b
})]
public ValueTuple< int,int> M()
{
返回新的ValueTuple< int,int>(1,2);
}
您可以使用以下代码获取该属性:
Type t = typeof(C);
MethodInfo方法= t.GetMethod(nameof(C.M));
var attr = method.ReturnParameter.GetCustomAttribute< TupleElementNamesAttribute>();
string []名称= attr.TransformNames;
I want to Map a ValueTuple to a class using reflection. Documentation says that there is a Attribute attached to ValueTuple with parameters names (others than Item1, Item2, etc...) but I can't see any Attribute.
Disassembly shows nothing.
What's happens?
Example:
public static T ToStruct<T, T1,T2>(this ValueTuple<T1,T2> tuple) where T : struct
Via reflection can't get Item1, Item2 names to match with T fields via reflection.
You should have the TupleElementNames
attribute on the method created by the compiler.
See this code:
public class C {
public (int a, int b) M() {
return (1, 2);
}
}
Which compiles to:
[return: TupleElementNames(new string[] {
"a",
"b"
})]
public ValueTuple<int, int> M()
{
return new ValueTuple<int, int>(1, 2);
}
You can get that attribute using this code:
Type t = typeof(C);
MethodInfo method = t.GetMethod(nameof(C.M));
var attr = method.ReturnParameter.GetCustomAttribute<TupleElementNamesAttribute>();
string[] names = attr.TransformNames;
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