class

问题 I have a very simple program that doesn't compile due to multiple definition error. It is here: main.cpp #include <iostream> #include "read_p.h" using namespace std; int main() { return 0; } read_p.cpp #include "read_p.h" using namespace std; void read_p() { /* some code here */ } read_p.h #ifndef READ_P_H #define READ_P_H #include "buildings.h" void read_p(); #endif buildings.h #ifndef BUILDINGS_H #define BUILDINGS_H #include "flag.h" using namespace std; /* some class here */ #endif flag.h

问题 I am trying to figure out how I can pass a variable as the declaration type (object) for a class in Python 3. Example: #class defintion class TestClass(Document): test = IntField() me = MongoEngine(app) testInstance = TestClass(me.Document) # How do i pass the Document variable I tried passing an instance of the MongoEngine variable as a variable to the TestClass but this isn't working properly? 回答1: I think you need to structure your class slightly different. Don't put Document in the class

问题 This question already has answers here : “R cannot be resolved to a variable”? [duplicate] (30 answers) Closed 6 years ago . Here's my code: package com.example.connecttest; import java.io.IOException; import java.io.OutputStream; import java.util.UUID; import com.example.bttest.R; import android.app.Activity; import android.bluetooth.BluetoothAdapter; import android.bluetooth.BluetoothDevice; import android.bluetooth.BluetoothSocket; import android.content.Intent; import android.os.Bundle;

问题 what's the best practise for registering window classes for a win32 program? Do you register every class in the WinMain function or as they're required? 回答1: I used to do them as they're required, no need doing it before they're needed. 回答2: No Need of registering if you using MFC because this will be doing in the backgrounds.. but if using win32 you need to register a windows class in WNDCLASS structure if you want to uise a windproc for your custom message handling see the MSDN link http:/

问题 I’m trying to create a password programme that lets the user create an account and then be able to change username, password and access the account. This is where I’m at so far: class 2 import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.event.*; import java.awt.event.ActionListener; import java.awt.event.ActionEvent; public class mainPage extends JFrame { create_account crAcc = new create_account(); change_username chU = new change_username(); change_password

问题 I've developed a recent interest in (re-)learning programming, so I have taken up C++ as it is a commonly used language. However, I've ran into a roadblock, and I have doubts whether my solution is the best way to go around it. I have a relatively complex class (for me anyways), with around 20 variables, which have been divided into 4 groups for simplification. It also has a parent class which is called during object initialization. However, I do not have a need to set these to values other

问题 How would I write a class in C# that represents an HSL color and an RGB color? Once I have that, is it possible to add a method that prints out each of the class attributes? I've heard about ToString() , but I'm not sure how to use it. Some sample code would be very useful, as I am a student and trying to learn how to use C#. Thanks! 回答1: People get annoyed when you post "questions" asking others to write code for you. Lots of questions from new users seem to ask for this, and yours even does

问题 Suppose I have a class, call it class1, with 3 class variables var1,var2,var3, and __init__ method, which assigns passed arguments to the class variables: class class1(object): var1 = 0 var2 = 0 var3 = 0 def __init__(self,a,b,c): class1.var1 = a class1.var2 = b class1.var3 = c Now I'm going to make two instances of the same class: obj1 = class1(1,2,3) obj2 = class1(4,5,6) And now, let's take a look at variables values: print (obj1.var1, obj1.var2,obj1.var3) 4 5 6 print (obj2.var1, obj2.var2

问题 This question already has answers here : Closed 6 years ago . Possible Duplicate: Initializing fields in constructor - initializer list vs constructor body In a lecture I attended, the lecturer talked briefly in C++ about non-default class constructors. He stated specifically that one version was preferable to the other. He showed these two examples: Point::Point(double x, double y, double z) : x_(x), y_(y), z_(z) {} Point::Point(double x, double y, double z) { x_= x; y_= y; z_= z; } He

问题 This question already has answers here : Closed 6 years ago . Possible Duplicate: Initializing fields in constructor - initializer list vs constructor body In a lecture I attended, the lecturer talked briefly in C++ about non-default class constructors. He stated specifically that one version was preferable to the other. He showed these two examples: Point::Point(double x, double y, double z) : x_(x), y_(y), z_(z) {} Point::Point(double x, double y, double z) { x_= x; y_= y; z_= z; } He