Question

我对C ++很陌生，我真的很想尝试定义一个类ConflictGraph的单个实例，并从另一个类ConvexHullBuilder内的不同方法访问它的方法

出于问题的原因，我需要在ConflictGraph中的某个点初始化ConvexHullBuilder::computeConvexHull()，当我有一些顶点和dcel时，我需要调用ConflictGraph's initialize()正确初始化ConflictGraph。这很好。

当我尝试在lookForVisibleFaces()内调用ConflictGraph ConvexHullBuilder::finalizeConvexHull时出现问题。

我收到以下错误

错误：'conflictGraph'未在此范围内声明

facesVisible = conflictGraph.lookForVisibleFaces（remainingVertices [i]）;
                 ^

这些类型有点棘手，但不要注意它们。我只需要了解如何在内部类方法中访问外部类方法

ConflictGraph.h ：

class ConflictGraph{
public:
    ConflictGraph(DrawableDcel* dcel, std::vector<Dcel::Vertex*> vertices);
    void initializeConflictGraph();
    std::set<Dcel::Face*>* lookForVisibleFaces(Dcel::Vertex*);
private:
    DrawableDcel *dcel;
    std::vector<Dcel::Vertex*> tetrahedronVertices;

    void checkVisibility();

}

ConflictGraph.cpp ：

#include "conflictgraph.h"

/**
 * @brief ConflictGraph::ConflictGraph() Constructor
 * @params takes dcel and tetrahedron vertices as input
 */
ConflictGraph::ConflictGraph(DrawableDcel* dcel, std::vector<Dcel::Vertex*> tetrahedronVertices){
    this->dcel = dcel;
    this->tetrahedronVertices = tetrahedronVertices;
}

/**
 * @brief ConflictGraph::initializeConflictGraph() initializes the conflict graph
 */
void ConflictGraph::initializeConflictGraph(){
    //Check which faces see which vertices and viceversa
    checkVisibility();//Works
}

/**
 * @brief lookForVisibleFaces(Dcel::Vertex* vertex) finds which faces are visible from a given vertex
 * @param VERTEX vertex given vertex
 * @retuns map of visible faces and passed Vertex
 */
std::set<FACE>* ConflictGraph::lookForVisibleFaces(Dcel::Vertex* vertex){
 . . .
}

ConvexHullBuilder.h ：

#include "conflictgraph.h"

class ConvexHullBuilder{

public:
    ConvexHullBuilder(DrawableDcel* dcel);
    void computeConvexHull();

private:
    DrawableDcel *dcel;
    void finalizeConvexHull(std::vector<Dcel::Vertex*);
};

ConvexHullBuilder.cpp

#include "convexhullbuilder.h"

/**
 * @brief ConvexHullBuilder::ConvexHullBuilder() Conmstructor
 * @params takes dcel as input
 */
ConvexHullBuilder::ConvexHullBuilder(DrawableDcel* dcel){
   this->dcel = dcel;
}

/**
 * @brief ConvexHullBuilder::computeConvexHull() takes dcel as input.
 *        Starts the algorithm calling all the different functions needed.
 *        Adds Vertices, Builds a Tetrahedron . . .
 */
void ConvexHullBuilder::computeConvexHull(){
. . .
/** VerticesForCG is an array of pointers to vertex, properly filled
    allVertices contains all the remaining vertices**/
//Initializes Conflict Graph with Dcel And First 4 Vertices
    ConflictGraph conflictGraph = ConflictGraph(dcel, verticesForCG);
    conflictGraph.initializeConflictGraph(); //Works

    //Loop through remaining vertices
    finalizeConvexHull(allVertices);//Does not Work

}

/**
 * @brief ConvexHullBuilder::finalizeConvexHull starts last phase to build the convex hull
 * @param VERTEX_POINTERS_LIST remainingVertices i=4 -> n vertices
 */
void ConvexHullBuilder::finalizeConvexHull(std::vector<Dcel::Vertex* remainingVertices){

    //Loop through remaining vertices
    for(unsigned int i=4; i<remainingVertices.size(); i++){

       //Initializing faces visible by a vertex
       std::set<Dcel::Face*>* facesVisible;

      //Check Which faces sees i-Vertex and assigning them
      facesVisible = conflictGraph.lookForVisibleFaces(remainingVertices[i]);//Error

    }
}

修改

我也尝试将ConflictGraph个实例传递给ConvexHullBuilder.h

private:
    DrawableDcel *dcel;
    ConflictGraph *conflictGraph;

在ConvexHullBuilder.cpp：

{
  //Initializes Conflict Graph with Dcel And First 4 Vertices
  this->conflictGraph = new ConflictGraph(dcel, verticesForCG);
  conflictGraph->initializeConflictGraph();

  //Loop through remaining vertices
  finalizeConvexHull(allVertices);
}

{
  facesVisible = conflictGraph->lookForVisibleFaces(remainingVertices[i]);
}

但在ConvexHullBuilder.h我得到了：

ConflictGraph未命名类型

我试着看看SO上的其他答案，但我无法解决他们的问题。

导致此错误的原因是什么？我怎么能阻止这个？如何在内部类不同的方法上使用不同的外部类方法？

Answer 1

您正试图在cinflictGraph内使用finalizeConvexHull。但是，它在computeConvexHull中被删除了。成员函数不会在彼此之间共享本地资源。

<强>解决方案：

在不深入思考系统的情况下，一种可能的解决方案是将conflictGraph声明为类ConvexHullBuilder的私有成员变量。因此，您可以在两个成员函数中使用它。

Answer 2

namespace App\Engine\Threads\ThreadClass; use Illuminate\Support\Facades\Log; class TestThread extends \Thread { private $threadID; public function __construct($threadID) { $this->threadID = $threadID; } /** * @return mixed */ public function getThreadID() { return $this->threadID; } public function run() { $this->threadID = $this->threadID.''.mt_rand(4000, 5000); } }在方法conflictGraph中声明为局部变量，因此它仅在调用该函数时存在。并且只能在该功能中访问。 ConvexHullBuilder::computeConvexHull()会调用finalizeConvexHull，因此computeConvexHull至少在通话时存在，但为了让conflictGraph能够访问它，您需要将它作为参数传递给该函数。

Answer 3

变量的范围始终是它内部的块。

您需要在第二个函数中声明conflictGraph。

Answer 4

您需要声明

private:
ConflictGraph conflictGraph;

“ConvexHullBuilder.h”文件中的

并在“ConvexHullBuilder.cpp”文件中声明为：

ConvexHullBuilder::ConvexHullBuilder(DrawableDcel* dcel){
   this->dcel = dcel;
   conflictGraph = ConflictGraph(dcel, verticesForCG);
}

然后你可以在“ConvexHullBuilder.cpp”文件中的任何函数中使用conflictGraph对象

Answer 5

我设法解决了这个问题。它是由两个类中的includes引起的。我只需要include module个header个included。例如，我必须仅在ConflictGraph.h而不是在ConvexHullBuilder中执行包含。

以下是我能够从ConflictGraph内部ConvexHullBuilder函数中访问private: . . . ConflictGraph *conflictGraph;的不同方法

<强> ConvexHullBuilder.h ：

void ConvexHullBuilder::computeConvexHull(){

  conflictGraph = new ConflictGraph(dcel, params);

  conflictGraph->initializeConflictGraph();
  finalizeConvexHull(parameters);

}

void ConvexHullBuilder::finalizeConvexHull(myType parameters){

  conflictGraph->lookForVisibleFaces(someParams);
}

<强> ConvexHullBuilder.cpp ：

pdfFileText.replaceAll("\\s+", " ").contains(institution)

＆＃39;类实例对象＆＃39;在这方面没有申明

5 个答案: