delegates

问题 Hi I'm trying to create a function that dynamically creates a delegate with the same return value and the same parameters as a MethodInfo it receives as parameter and also and this is very important the same parameter names! What I did so far is create a function that returns a lambda that receives the same parameter types and has the same return value as the MethodInfo but it doesn't have the parameter names: static void Example() { Person adam = new Person(); MethodInfo method = typeof

问题 Hi I'm trying to create a function that dynamically creates a delegate with the same return value and the same parameters as a MethodInfo it receives as parameter and also and this is very important the same parameter names! What I did so far is create a function that returns a lambda that receives the same parameter types and has the same return value as the MethodInfo but it doesn't have the parameter names: static void Example() { Person adam = new Person(); MethodInfo method = typeof

问题 I want to exceute some piece of code in separate AppDomain with delegate. How can I do this? UPD1 : some more details about my problem My program processing some data (one iteration is: get some data from DB, evaluate it and create assemblies at runtime, execute dynamic assemblies and write results to DB). Current solution: each iteration running in separate thread. Better solution: each iteration running in separate AppDomain (to unload dynamic asseblies). UPD2 : All, thanks for answers. I

问题 I'm trying to run helloandroid application on a Motorola Milestone A853. I typed "adb devices" and the mobile is properly recognized. However, when I try to run the application Eclipse always stuck at 27% "Launching delegate". Which could be the reason? 回答1: Had the same 27% problem with an emulator. It only got fixed after I deleted the AVD and recreated it, so this is very likely device/emulator related (and furthermore restarting the ADB did not fix the problem). EDIT: Found this over at

问题 When branching to select a function, it might make sense to use the ternary operator to select a function, but this is impossible. Why? public class Demo { protected bool branch; protected void demo1 () {} protected void demo2 () {} public Action DoesntWork() { return branch ? demo1 : demo2; } } The compiler produces the following error: Cannot implicitly convert type `method group' to `System.Action' 回答1: The problem is that demo1 is not a simple expression, it is a method . And methods can

问题 This question already has answers here : Closed 9 years ago . Possible Duplicates: When would you use delegates in C#? The purpose of delegates I have seen many question regarding the use of delegates. I am still not clear where and WHY would you use delegates instead of calling the method directly. I have heard this phrase many times: "The delegate object can then be passed to code which can call the referenced method, without having to know at compile time which method will be invoked." I

问题 In C# you can define delegates anonymously (even though they are nothing more than syntactic sugar). For example, I can do this: public string DoSomething(Func<string, string> someDelegate) { // Do something involving someDelegate(string s) } DoSomething(delegate(string s){ return s += "asd"; }); DoSomething(delegate(string s){ return s.Reverse(); }); Is it possible to pass code like this in Java? I'm using the processing framework, which has a quite old version of Java (it doesn't have

问题 Is it possible to have a delegate as the parameter of an attribute? Like this: public delegate IPropertySet ConnectionPropertiesDelegate(); public static class TestDelegate { public static IPropertySet GetConnection() { return new PropertySetClass(); } } [AttributeUsage(AttributeTargets.Class | AttributeTargets.Interface,AllowMultiple=false,Inherited=true)] public class WorkspaceAttribute : Attribute { public ConnectionPropertiesDelegate ConnectionDelegate { get; set; } public

问题 Is it possible to have a delegate as the parameter of an attribute? Like this: public delegate IPropertySet ConnectionPropertiesDelegate(); public static class TestDelegate { public static IPropertySet GetConnection() { return new PropertySetClass(); } } [AttributeUsage(AttributeTargets.Class | AttributeTargets.Interface,AllowMultiple=false,Inherited=true)] public class WorkspaceAttribute : Attribute { public ConnectionPropertiesDelegate ConnectionDelegate { get; set; } public

问题 I've read conflicting opinions as to whether every BeginInvoke() has to be matched by an EndInvoke(). Are there any leaks or other problems associated with NOT calling EndInvoke()? 回答1: Delegate.EndInvoke is documented as a thou shalt call this (i.e. necessary - else leaks happen) - from msdn: Important Note No matter which technique you use, always call EndInvoke to complete your asynchronous call. Control.EndInvoke is OK to ignore for fire-and-forget methods - from msdn: You can call