c#-4.0

问题 I have a project that has 4 entity data model.for building them I don't want save a connection string in my project and I want store a connection string in app.config files and share it between my models.How I can do this? thanks 回答1: Assuming DbContext and model/database first. Leave the generated EF connection strings in your app.config file intact. As Arthur said, they contain the paths to the EF metadata (csdl/ssdl/msl). They are also used during development by the model designer. Add a

问题 I am having trouble finding a NoSQL databases that officially support MonoTouch via a local DB on the device. If their are, could someone provide a list of them here. 回答1: According to http://nosql-database.org/ there's siaqodb. Note that others might support MonoTouch without being mentioned in that site. Edit : a few more clicks shows that HSS Database (from the same list) also supports MonoTouch. You might also want to look at which ones support iOS (e.g. with Objective C) and see if

问题 I have read countless blogs, posts and StackOverflow questions about the new features of C# 4.0. Even new WPF 4.0 features have started to come out in the open. What I could not find and will like to know: What are the major changes to CLR 4.0 from a C#/WPF developer perspective? What are the major changes to CLR 4.0 as a whole? I think, internally, most changes are for the new dynamic languages and parallel programming. But are there any other major improvements? Because language

问题 I have a two types that are very similar (i.e. the member names are very similar). Is there an elegant way to copy one type to another, without having to copy each individual member by hand? Update Here is some sample source code: main() { FromCsvFile x = new FromCsvFile(fileName); OptionsEnt y = x.ToOptionsEnt(); // See helper function below. } // Chained helper function to convert type "FromCsvFile" to type "OptionsEnt". // Want to replace this with something more elegant (perhaps with

问题 I have a two types that are very similar (i.e. the member names are very similar). Is there an elegant way to copy one type to another, without having to copy each individual member by hand? Update Here is some sample source code: main() { FromCsvFile x = new FromCsvFile(fileName); OptionsEnt y = x.ToOptionsEnt(); // See helper function below. } // Chained helper function to convert type "FromCsvFile" to type "OptionsEnt". // Want to replace this with something more elegant (perhaps with

问题 I have a two types that are very similar (i.e. the member names are very similar). Is there an elegant way to copy one type to another, without having to copy each individual member by hand? Update Here is some sample source code: main() { FromCsvFile x = new FromCsvFile(fileName); OptionsEnt y = x.ToOptionsEnt(); // See helper function below. } // Chained helper function to convert type "FromCsvFile" to type "OptionsEnt". // Want to replace this with something more elegant (perhaps with

问题 why and how this works in the below code dynamic x = ( c== 'a') ? new D1() :x= new D2(); but not this dynamic x = ( c== 'a') ? new D1() : new D2(); Code class Program { static void Main(string[] args) { var c = Console.ReadKey().KeyChar; dynamic x = ( c== 'a') ? new D1() :x= new D2(); x.Print(); Console.ReadKey(); } } class D1 { public void Print() { Console.WriteLine("D1"); } } class D2 { public void Print() { Console.WriteLine("D2"); } } 回答1: This has nothing to do with dynamic. This is

问题 why and how this works in the below code dynamic x = ( c== 'a') ? new D1() :x= new D2(); but not this dynamic x = ( c== 'a') ? new D1() : new D2(); Code class Program { static void Main(string[] args) { var c = Console.ReadKey().KeyChar; dynamic x = ( c== 'a') ? new D1() :x= new D2(); x.Print(); Console.ReadKey(); } } class D1 { public void Print() { Console.WriteLine("D1"); } } class D2 { public void Print() { Console.WriteLine("D2"); } } 回答1: This has nothing to do with dynamic. This is

问题 why and how this works in the below code dynamic x = ( c== 'a') ? new D1() :x= new D2(); but not this dynamic x = ( c== 'a') ? new D1() : new D2(); Code class Program { static void Main(string[] args) { var c = Console.ReadKey().KeyChar; dynamic x = ( c== 'a') ? new D1() :x= new D2(); x.Print(); Console.ReadKey(); } } class D1 { public void Print() { Console.WriteLine("D1"); } } class D2 { public void Print() { Console.WriteLine("D2"); } } 回答1: This has nothing to do with dynamic. This is

问题 I've created my own custom pseudo enumerations within my domain model to allow me to have some more verbose values. For example, my class is as follows: public abstract class Enumeration<X, Y> : IComparable where X : IComparable { public Enumeration(X value, Y displayName) { } public Y DisplayName { get { return _displayName; } } public X Value { get { return _value; } } } And a class that inherits it would be: public class JobType : Enumeration<string, string> { public static JobType