dynamictype

来源： https://stackoverflow.com/questions/64484213/why-is-a-jvalue-held-in-a-dynamic-variable-assignable-to-a-string-variable-b

来源： https://stackoverflow.com/questions/64484213/why-is-a-jvalue-held-in-a-dynamic-variable-assignable-to-a-string-variable-b

问题 I am trying to convert an Object to dynamic type but the conversion is failing with RunTimeBinder exception. I tried using two methods that I came across in Stackoverflow answers. Code 1: object objSum; dynamic dynSum; objSum = dataTableColumnChart.Compute(String.Format("Count({0})", strColumnName), ""); dynSum = Convert.ChangeType(objSum, objSum.GetType());\ Debug.Writeline(dynSum); Code 2: dynSum=objSum; Debug.Writeline(dynSum); The exception thrown is this: A first chance exception of type

问题 I am trying to convert an Object to dynamic type but the conversion is failing with RunTimeBinder exception. I tried using two methods that I came across in Stackoverflow answers. Code 1: object objSum; dynamic dynSum; objSum = dataTableColumnChart.Compute(String.Format("Count({0})", strColumnName), ""); dynSum = Convert.ChangeType(objSum, objSum.GetType());\ Debug.Writeline(dynSum); Code 2: dynSum=objSum; Debug.Writeline(dynSum); The exception thrown is this: A first chance exception of type

问题 Suppose there is a static object with type A . class A { public string b; public int c; public bool d; public A e; . . . } A a = new A(){ b = "string", c = 12, d = true e = new A(){ b = "another string", c = 23 } }; I want to deep clone this object into a dynamic object with all of its properties. 回答1: I would enumerate the properties of the object (a.GetType().GetProperties()), destinguish between built-in types, structs and classes and use ExpandoObject to build the dynamic object. 回答2: The

问题 I have function to fetch image like dynamic imgBinary = _repository.fetchImage(productId); And I want to add this into List of Image List<NetworkImage> listImages = new List<NetworkImage>(); So like dynamic imgBinary = _repository.fetchImage(productId); listImages.add(imgBinary); How to cast this? 回答1: Ok , So you Can Try .then method. As _repository.fetchImage(productId); is Future. so you can try - List<NetworkImage> listImages = List<NetworkImage>(); Future<dynamic> imgBinary = _repository

问题 I'm trying to do something like this: void someMethod(TypeA object) { ... } void someMethod(TypeB object) { ... } object getObject() { if (...) return new TypeA(); else return new TypeB(); } object obj = getObject(); (obj.GetType()) obj; // won't compile someMethod(obj); Obviously I'm confused here. I know I could make this work by just writing out a conditional statement -- if (obj.GetType() == typeof(TypeA)) obj = (TypeA)obj; else if (obj.GetType() == typeof(TypeB)) obj = (TypeB)obj; -- but

问题 I use MVC3 Grid to show Events. What I need is somehow integrate on mouse event for the "NAME" to show "Description" of the item. How do I can implement? Thanks for any clue!!! @{ var grid = new WebGrid(source: Model.Events, defaultSort: "Name", rowsPerPage: 20); } @if (Model != null) { @grid.GetHtml( tableStyle: "grid", headerStyle: "head", alternatingRowStyle: "alt", rowStyle: "row", selectedRowStyle: "selected-row", columns: grid.Columns( grid.Column("Name", "Event", style: "column"), grid

问题 Put a playground below that shows my issue and it's output. I need to write a method you can pass AnyObject? into, then determine the type of that object. If it's an array, I'll also need to determine it's Element type. This works fine before the method is called, but after I can't get at the types. Specifically, the element type doesn't come back proper due to casting. Playground //: Playground - noun: a place where people can play import UIKit import Foundation extension Array { var

问题 Optional chaining returns always an optional value. To reflect the fact that optional chaining can be called on a nil value, the result of an optional chaining call is always an optional value, even if the property, method, or subscript you are querying returns a nonoptional value. The Swift Programming Language Why the heck does in a playground the type not optional? let stringOptEmpty: String? = "" stringOptEmpty?.isEmpty // is true stringOptEmpty?.isEmpty.dynamicType // Bool.Type But the