class

问题 Is it possible to assign my own class to the HTML.DropDownListFor() helper? 回答1: One of the overloaded method has an object htmlAttributes as last parameter in which you can specify extra attributes to be added to the generated html: Html.DropDownListFor(..., new { "class" = "myclassname" }; http://msdn.microsoft.com/library/ee703670.aspx 回答2: Didier's answer is mostly correct, but to define a class value in htmlAttributes object, you need to use this syntax: Html.DropDownListFor(..., new {

问题 In PHP 5.4, I believe something like this is valid: echo ( new DateTime( '2014-04-05 10:36am' ))->format( 'Y-m-d g:ia' ); On PHP 5.3, I currently do something like this: $date = new DateTime( '2014-04-05 10:36am' ); echo $date->format( 'Y-m-d g:ia' ); Any way to combine those two lines into a single line in PHP 5.3 (and I don't mean by concatenating the lines)? Or will I have to upgrade to >=5.4 to have that option? 回答1: Will I have to upgrade to >=5.4 to have that option? Yes. You need to

问题 I have the following class: class Point(object): __slots__= ("x","y","z","data","classification") def __init__(self,x,y,z,n=None): self.x = float(x) self.y = float(y) self.z = float(z) self.data = [self.x,self.y,self.z] def set_classification(self,n): self.classification = n p = Point(10,20,30) p.data [10.0, 20.0, 30.0] p.set_classification(0) p.data [10.0, 20.0, 30.0] I have the following questions: First, the parameters to create the Point object are x,y , and z . Classification is an

问题 I've been reading this topic on how to use class modules. My goal is to improve my code performance and readability so I think I'm in the right path. But I have some questions about the limitations. In my head i want to do this: Is it possible to achieve such a structure? The topic I've read has very few examples and this is not handled. I'm assuming this would be possible with collections of collections, but I not sure how to look for this. My data comes from 2 tables, one has all the items

问题 I've a doubt about this question, not relatively to a specific language: when I write a class, maybe in C++ or Java, the memory for member function code is allocated once or at every instance? So, in certain cases, is it better to write them as static? thanks for replies 回答1: Nope, the data portion of the code is loaded separately from the executable section when the OS loads your program into memory. They reside usually into different memory regions (typically, the executable section is a

问题 If the input is for example "banana", I want to print the kcal of banana. I tried something like this (and failed): string input; cin >> input; cout << input.Kcal << endl; I know that I can do it with if-statements like: string input; cin >> input; if(input == "banana") { cout << banana.Kcal << endl; } But there I must write very much code when I have more then 1000 foods... There is my declaration and definition of my banana object. Every object has kcal. food banana; banana.Kcal = 89; My

问题 I'm having a little problem where I want two different classes to be able to share and make changes to another class object. I've got a HumanPlayer class, a ComputerPlayer class, and a Board class. The two player classes need to be able to interact with the one Board class. I thought that I could pass a reference to the same Board object to each class but it doesn't appear to be working the way I want it to. Here's part of what's in main and I'll describe what's happening as best I can: /

问题 I have class NumberArray in NumberArray.h class NumberArray { private: double *aPtr; int arraySize; public: NumberArray(int size, double value); // ~NumberArray() { if (arraySize > 0) delete [ ] aPtr;} //commented out to avoid problems with the //default copy constructor void print() const; void setValue(double value); }; When I go to write the print function in NumberArray.cpp void NumberArray::print() { for (int index = 0; index < arraySize; index++) cout << aPtr[index] << " "; } It gives

问题 I have class NumberArray in NumberArray.h class NumberArray { private: double *aPtr; int arraySize; public: NumberArray(int size, double value); // ~NumberArray() { if (arraySize > 0) delete [ ] aPtr;} //commented out to avoid problems with the //default copy constructor void print() const; void setValue(double value); }; When I go to write the print function in NumberArray.cpp void NumberArray::print() { for (int index = 0; index < arraySize; index++) cout << aPtr[index] << " "; } It gives

问题 I have already created a class and a subclass and have a bunch of code in both. I've created an interface in the parent class and I have no idea how to make my child class implement the interface :/ The code is: class Car { public interface ISmth { void MyMethod(); } } class MyCar : Car { //implement the interface } 回答1: This is how your code should probably be laid out. public interface ISmth { void MyMethod(); } class Car { } class MyCar : Car, ISmth { public void MyMethod() { } } There