我想用一个字符串访问一个动态c#属性的值:
动态d = new {value1 = "some"， value2 = "random"， value3 = "value"};
如果我只有“value2”作为字符串，我如何才能得到d.value2(“random”)的值?在javascript中，我可以做d["value2"]来访问值("random")，但我不确定如何用c#和反射来做到这一点。我最接近的说法是:
“value2”d.GetType () . getproperty()……但我不知道如何从中获得实际价值。
一如既往，谢谢你的帮助!
当前回答
一些解决方案不是工作的valuekind对象，我从一个json字符串获得的，也许是因为我没有一个具体的类型在我的代码，类似于对象，我将从json字符串获得，所以我是如何去做的
JsonElement myObject = System.Text.Json.JsonSerializer.Deserialize<JsonElement>(jsonStringRepresentationOfMyObject);
/*In this case I know that there is a property with
the name Code, otherwise use TryGetProperty. This will
still return a JsonElement*/
JsonElement propertyCode = myObject.GetProperty("Code");
/*Now with the JsonElement that represents the property,
you can use several methods to retrieve the actual value,
in this case I know that the value in the property is a string,
so I use the GetString method on the object. If I knew the value
was a double, then I would use the GetDouble() method on the object*/
string code = propertyCode.GetString();
这对我很有用
其他回答
Dynamitey是一个开源的。net std库，让你像动态关键字一样调用它，但是使用一个字符串作为属性名，而不是编译器为你做它，它最终等于反射速度(这几乎不如使用动态关键字快，但这是由于动态缓存的额外开销，其中编译器静态缓存)。
Dynamic.InvokeGet(d,"value2");
在Newtonsoft.Json.JsonConvert.DeserializeObject中使用dynamic:
// Get JSON string of object
var obj = new { value1 = "some", value2 = "random", value3 = "value" };
var jsonString = JsonConvert.SerializeObject(obj);
// Use dynamic with JsonConvert.DeserializeObject
dynamic d = JsonConvert.DeserializeObject(jsonString);
// output = "some"
Console.WriteLine(d["value1"]);
示例: https://dotnetfiddle.net/XGBLU1
在。net core 3.1中，你可以这样尝试
d?.value2 , d?.value3
一些解决方案不是工作的valuekind对象，我从一个json字符串获得的，也许是因为我没有一个具体的类型在我的代码，类似于对象，我将从json字符串获得，所以我是如何去做的
JsonElement myObject = System.Text.Json.JsonSerializer.Deserialize<JsonElement>(jsonStringRepresentationOfMyObject);
/*In this case I know that there is a property with
the name Code, otherwise use TryGetProperty. This will
still return a JsonElement*/
JsonElement propertyCode = myObject.GetProperty("Code");
/*Now with the JsonElement that represents the property,
you can use several methods to retrieve the actual value,
in this case I know that the value in the property is a string,
so I use the GetString method on the object. If I knew the value
was a double, then I would use the GetDouble() method on the object*/
string code = propertyCode.GetString();
这对我很有用
public static object GetProperty(object target, string name)
{
var site = System.Runtime.CompilerServices.CallSite<Func<System.Runtime.CompilerServices.CallSite, object, object>>.Create(Microsoft.CSharp.RuntimeBinder.Binder.GetMember(0, name, target.GetType(), new[]{Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfo.Create(0,null)}));
return site.Target(site, target);
}
添加对Microsoft.CSharp的引用。也适用于动态类型和私有属性和字段。
编辑:虽然这种方法是有效的，但是从Microsoft.VisualBasic.dll程序集中可以找到几乎快20倍的方法:
public static object GetProperty(object target, string name)
{
return Microsoft.VisualBasic.CompilerServices.Versioned.CallByName(target, name, CallType.Get);
}
