dynamic

问题 To implement "method-missing"-semantics and such in C# 4.0, you have to implement IDynamicObject: public interface IDynamicObject { MetaObject GetMetaObject(Expression parameter); } As far as I can figure out IDynamicObject is actually part of the DLR, so it is not new. But I have not been able to find much documentation on it. There are some very simple example implementations out there (f.x. here and here), but could anyone point me to more complete implementations or some real

问题 Lets say I have a base class with 100 children: class Base { virtual void feed(); ... }; class Child1 : public Base { void feed(); //specific procedure for feeding Child1 ... }; ... class Child100 : public Base { void feed(); //specific procedure for feeding Child100 ... }; At runtime I want to read a file that contains which children to create and feed. Lets say I've read the file and the vector of strings "names" contains the names of the child classes (ie. Child1, Child4, Child99). Now I'm

问题 One example of using the DLR in C# is as follows: dynamic dyn = new MyObject(); dyn.MyMethod(); //resolved at runtime what would be the equivalent in F#? Thanks. 回答1: The ? operator has similar expressive power to the dynamic keyword in C# (but it can be only used for reading of properties, method invocation and setting of properties). There is no built-in implementation that would allow you to dynamically use properties or methods of a .NET class (via Reflection or DLR), but there are some

问题 I know that arrays are created dynamically, and creating them ahead of time isn't really necessary, but how would one do that with a 2D array? The same way? (for$j) { for($i) { $array[j][i] = "data"; } } Something like that? Obviously real for loops, of course. 回答1: At its absolute simplest, a 2D dimensional array can be created as: <?php $emptyArray = array(array()); ?> Or as of PHP 5.4 you can also use: <?php $emptyArray = [[]]; ?> 回答2: You don't create a 2d array in PHP, not in the

问题 I hope you can help. I'm very new to jQuery and am working on a five- or six-level accordion menu for my side navigation. I got the majority of the code I have so far from Dane Peterson @ daneomatic.com (thanks Dane!). But, I'm stuck on one thing: I'd like to have my accordion/tree work like this: When I navigate down into, say, level three, and click on the link to open the page linked to that level, how do I indicate once the level three page loads that I'm on that page? Also, how do I keep

问题 I have looked all over the web for this answer but it seems to me that in order to horizontally center an image in div with absolute position, I need to know the dimensions of the image, but it's dynamic. Here is my html: <header> <div id="elogo"> <img src="http://www.ftiweb.com/images/eStore/eStore_wht50.png"> </div> <div id="nav">TOUR | MENU</div> </header> <div id="content"> <img class="ipad" src="http://ftiweb.com/images/eStore/Ipad_hand.png"> </div> <footer> <div id="foot">© FTIeStore

问题 If I need to assign a click function dynamically, is there a way to ensure the click function is only assigned once and not duplicated? this.click(function(){ alert('test'); }) 回答1: You can unbind the click event before you bind it again, that way you will only have one event attached to it: //assuming this is a jquery object. this.unbind("click"); this.click(function(){ alert("clicked once"); }); As of jQuery 1.7, click now uses .on (http://api.jquery.com/click/) so the correct code is now /

问题 If I need to assign a click function dynamically, is there a way to ensure the click function is only assigned once and not duplicated? this.click(function(){ alert('test'); }) 回答1: You can unbind the click event before you bind it again, that way you will only have one event attached to it: //assuming this is a jquery object. this.unbind("click"); this.click(function(){ alert("clicked once"); }); As of jQuery 1.7, click now uses .on (http://api.jquery.com/click/) so the correct code is now /

问题 Is it possible to load a specific package during runtime? I want to have a kind of plugins where each one has the same functions than the others but with different behaviour, and depending on the configuration file, load one or other. 回答1: You might consider executing the ‘plugin’ packages at runtime, by writing out a new program (say, to a temp directory) and executing via exec.Command, something along the lines of exec.Command("go", "run", files…).Run() You’ll see some similar code here.

问题 I'm currently working with a specialized, interpreted, programming language implemented in Java. As a very small part of the language, I'd like to add the ability to make calls into Java. Before I dive into all of the nitty-gritty of reflection, I was wondering if anyone knew of a general library for doing the "backend" part of invoking Java code reflectively. That is, I parse a string (I define the grammar) into some data structure that represents a Java method call (or constructor, or field