class

问题 Is there any possible method than looping, Enumerating the ICollection to convert them respectively to Typed List knowing the columns in the ICollection. I am using .net Framework 2.0, C#2.0. Expected answer would be something like this,a one liner List<Bills> bills = GetBills(DataView/DataRowView/ICollection); where Bills type would have BillNumber, BillDate, BilledTo as properties. The DataRowView/DataView would have corresponding Columns with records in them. Is there a factory build

问题 I understand what the "@objc" attribute does for protocols. What I don't understand is why it is added to classes, such as in the following example: @objc protocol CounterDataSource { optional func incrementForCount(count: Int) -> Int optional var fixedIncrement: Int { get } } @objc class Counter { var count = 0 var dataSource: CounterDataSource? func increment() { if let amount = dataSource?.incrementForCount?(count) { count += amount } else if let amount = dataSource?.fixedIncrement { count

问题 I would like construct a class composition that includes a function set_props for setting the instance variables of components. The application for this is in defining new objects for drawing in matplotlib. One example is that I would like to have a function drawMyArrow that draws an arrow with possibly different colors (and other specifications) for its head, tail, and arc. I would like to be able to pass various specifications for the head, tail, and arc via keyword arguments in drawMyArrow

问题 I've got a PHP code that selects a PDF file and converts it to a text file. I'm using an external library pdf-to-text with the composer. Following is the system display error: Fatal error: Uncaught Error: Class 'Pdf' not found in C:\xampp\htdocs\testcomposer\test2.php:6 Stack trace: #0 {main} thrown in C:\xampp\htdocs\testcomposer\test2.php on line 6 Project Structure : testcomposer app -Spatie -pdftotext -src -Exceptions -CouldNotExtractText.php -PdfNotFound.php -pdf.php -symfony vendor

问题 For some reason I'm getting a global name is not defined error here. The issue lies in the addClient method where I am incrementing my global variable joinID . It throws me an error NameError: global name 'joinID' is not defined . What am I doing wrong? class Chatroom: clients = [] joinID = 0 def __init__(self,name,refNum): self.refNum = refNum self.name = name def addClient(self,clientName): global clients global joinID joinID = joinID+1 clients.append(clientName, joinID) def removeClient

问题 This question already has answers here : What is the use of “ref” for reference-type variables in C#? (10 answers) “ref” keyword and reference types [duplicate] (4 answers) Closed 5 years ago . I just noticed .net allows us to do like this. public void Func1(ref String abc) { } I was wondering "ref" keyword makes any sense???? as String is a Class(reference type) Is it any different from. public void Func1(String abc) { } I am just asking as i am confused. either missing some concept or they

问题 I wonder if somebody has already met with a requirement to make a processing in Java depending on values defined in a .properties file and what would be the best approach to achieve that ? For example, a property file will have some key/value pairs like that: file.input=csv data.type=multi data.separator=; ...etc So in this case, depending on a property value(for example, 'csv'), I'll call CSV processing related classes, depending on 'data.type' value, I'll update the corresponding model

问题 I am new to PHP OOP. Below is my VERY FIRST class file. I would like to add more flexibility to this code, add functions so I can run queries and even assign the results (either fetch_assoc/fetch_array) to an array (Or var, etc) for latter use. The problem I am having with running queries, is that I am not able to put together both classes (nesting?): $db->Query->Select('myTable'); OR $db->Query->Select('myTable')->Where($pageID); OR $db->Query->Select('myTable')->Where($pageID)->OrderBy(

问题 I have a problem with Java GUI. It is hard to explain but I will do my best. I have 2 GUI classes one is class I and other is class G. Class I is initiated from main method. In the class I there is a field (instance of) class G. Reason being that class I collects vital information and passes it to instance of class G. When a button pressed in class I, that sets the class I frame visibility to false and instance of class G to true (showing up the G interface). Problem here is that I want to be

问题 I am new to python. Im trying to access the parent class variable in child class using super() method but it throws error "no arguments". Accessing class variable using class name works but i like to know whether it is possible to access them using super() method. class Parent(object): __props__ = ( ('a', str, 'a var'), ('b', int, 'b var') ) def __init__(self): self.test = 'foo' class Child(Parent): __props__ = super().__props__ + ( ('c', str, 'foo'), ) # Parent.__props__ def __init__(self):