我已在VS 2015 Community Edition中成功安装了FLTK。我正在处理其他标题，这是Stroustrup的书的一部分，用于构建图形并创建自定义窗口以附加它们。我的问题是，当我尝试编译时，我收到4个错误消息（加上23个警告）：
（主动）IntelliSense命名空间＆＃34; std＆＃34;没有会员 ＆＃34;矢量＆＃34; Win32Project1 c：\ Users \ Leonardo \ Documents \ Visual Studio 2015 \ Projects \ Win32Project1 \ Win32Project1 \ Window.h 17
错误C2873构建＆＃39; Vector＆＃39;：符号不能用于a using-declaration Win32Project1 c：\ users \ leonardo \ documents \ visual studio 2015 \ projects \ win32project1 \ win32project1 \ Window.h 17
错误C2039 Build＆＃39; Vector＆＃39;：不是其成员 ＆＃39; STD＆＃39; Win32Project1 c：\ users \ leonardo \ documents \ visual studio 2015 \ projects \ win32project1 \ win32project1 \ Window.h 17
错误C2440构建＆＃39;返回＆＃39;：无法转换为＆＃39; std :: ifstream＆＃39;至 ＆＃39;布尔＆＃39; Win32Project1 C：\ Users \ Leonardo \ Documents \ Visual Studio 2015 \ Projects \ Win32Project1 \ Win32Project1 \ Graph.cpp 371
我已按照此站点的步骤设置了Win32Project（不是控制台项目）：http://www.c-jump.com/bcc/common/Talk2/Cxx/FltkInstallVC/FltkInstallVC.html。 如果我运行测试示例，它完全可以正常工作，我想，正确安装了额外的库。
此外，我已添加了作者在项目中提供的每个头文件或源文件。
main.cpp中：
#include "std_lib_facilities.h"
#include "Graph.h"
#include "Simple_window.h"
int main()
{
using namespace Graph_lib;
Point tl{ 100,100 };
Simple_window win{ tl,600,400,"My Window" };
win.wait_for_button();
}
可以通过以下网址访问所有标头和源文件：http://www.stroustrup.com/Programming/Programming-code.zip
这里是Windows.h
//
// This is a GUI support code to the chapters 12-16 of the book
// "Programming -- Principles and Practice Using C++" by Bjarne Stroustrup
//
#ifndef WINDOW_GUARD
#define WINDOW_GUARD
#include <string>
#include <vector>
#include <FL/Fl.H>
#include <FL/Fl_Window.H>
#include "Point.h"
using std::string;
using std::vector;
namespace Graph_lib
{
class Shape; // "forward declare" Shape
class Widget;
//------------------------------------------------------------------------------
class Window : public Fl_Window {
public:
// let the system pick the location:
Window(int w, int h, const string& title);
// top left corner in xy
Window(Point xy, int w, int h, const string& title);
virtual ~Window() { }
int x_max() const { return w; }
int y_max() const { return h; }
void resize(int ww, int hh) { w=ww, h=hh; size(ww,hh); }
void set_label(const string& s) { copy_label(s.c_str()); }
void attach(Shape& s) { shapes.push_back(&s); }
void attach(Widget&);
void detach(Shape& s); // remove s from shapes
void detach(Widget& w); // remove w from window (deactivates callbacks)
void put_on_top(Shape& p); // put p on top of other shapes
protected:
void draw();
private:
vector<Shape*> shapes; // shapes attached to window
int w,h; // window size
void init();
};
和Graph.cpp
//
// This is a GUI support code to the chapters 12-16 of the book
// "Programming -- Principles and Practice Using C++" by Bjarne Stroustrup
//
#include <FL/Fl_GIF_Image.H>
#include <FL/Fl_JPEG_Image.H>
#include "Graph.h"
//------------------------------------------------------------------------------
namespace Graph_lib {
//------------------------------------------------------------------------------
Shape::Shape() :
lcolor(fl_color()), // default color for lines and characters
ls(0), // default style
fcolor(Color::invisible) // no fill
{}
//------------------------------------------------------------------------------
void Shape::add(Point p) // protected
{
points.push_back(p);
}
//------------------------------------------------------------------------------
void Shape::set_point(int i,Point p) // not used; not necessary so far
{
points[i] = p;
}
//------------------------------------------------------------------------------
void Shape::draw_lines() const
{
if (color().visibility() && 1<points.size()) // draw sole pixel?
for (unsigned int i=1; i<points.size(); ++i)
fl_line(points[i-1].x,points[i-1].y,points[i].x,points[i].y);
}
//------------------------------------------------------------------------------
void Shape::draw() const
{
Fl_Color oldc = fl_color();
// there is no good portable way of retrieving the current style
fl_color(lcolor.as_int()); // set color
fl_line_style(ls.style(),ls.width()); // set style
draw_lines();
fl_color(oldc); // reset color (to previous)
fl_line_style(0); // reset line style to default
}
//------------------------------------------------------------------------------
void Shape::move(int dx, int dy) // move the shape +=dx and +=dy
{
for (int i = 0; i<points.size(); ++i) {
points[i].x+=dx;
points[i].y+=dy;
}
}
//------------------------------------------------------------------------------
Line::Line(Point p1, Point p2) // construct a line from two points
{
add(p1); // add p1 to this shape
add(p2); // add p2 to this shape
}
//------------------------------------------------------------------------------
void Lines::add(Point p1, Point p2)
{
Shape::add(p1);
Shape::add(p2);
}
//------------------------------------------------------------------------------
// draw lines connecting pairs of points
void Lines::draw_lines() const
{
if (color().visibility())
for (int i=1; i<number_of_points(); i+=2)
fl_line(point(i-1).x,point(i-1).y,point(i).x,point(i).y);
}
//------------------------------------------------------------------------------
// does two lines (p1,p2) and (p3,p4) intersect?
// if se return the distance of the intersect point as distances from p1
inline pair<double,double> line_intersect(Point p1, Point p2, Point p3, Point p4, bool& parallel)
{
double x1 = p1.x;
double x2 = p2.x;
double x3 = p3.x;
double x4 = p4.x;
double y1 = p1.y;
double y2 = p2.y;
double y3 = p3.y;
double y4 = p4.y;
double denom = ((y4 - y3)*(x2-x1) - (x4-x3)*(y2-y1));
if (denom == 0){
parallel= true;
return pair<double,double>(0,0);
}
parallel = false;
return pair<double,double>( ((x4-x3)*(y1-y3) - (y4-y3)*(x1-x3))/denom,
((x2-x1)*(y1-y3) - (y2-y1)*(x1-x3))/denom);
}
//------------------------------------------------------------------------------
//intersection between two line segments
//Returns true if the two segments intersect,
//in which case intersection is set to the point of intersection
bool line_segment_intersect(Point p1, Point p2, Point p3, Point p4, Point& intersection){
bool parallel;
pair<double,double> u = line_intersect(p1,p2,p3,p4,parallel);
if (parallel || u.first < 0 || u.first > 1 || u.second < 0 || u.second > 1) return false;
intersection.x = p1.x + u.first*(p2.x - p1.x);
intersection.y = p1.y + u.first*(p2.y - p1.y);
return true;
}
//------------------------------------------------------------------------------
void Polygon::add(Point p)
{
int np = number_of_points();
if (1<np) { // check that thenew line isn't parallel to the previous one
if (p==point(np-1)) error("polygon point equal to previous point");
bool parallel;
line_intersect(point(np-1),p,point(np-2),point(np-1),parallel);
if (parallel)
error("two polygon points lie in a straight line");
}
for (int i = 1; i<np-1; ++i) { // check that new segment doesn't interset and old point
Point ignore(0,0);
if (line_segment_intersect(point(np-1),p,point(i-1),point(i),ignore))
error("intersect in polygon");
}
Closed_polyline::add(p);
}
//------------------------------------------------------------------------------
void Polygon::draw_lines() const
{
if (number_of_points() < 3) error("less than 3 points in a Polygon");
Closed_polyline::draw_lines();
}
//------------------------------------------------------------------------------
void Open_polyline::draw_lines() const
{
if (fill_color().visibility()) {
fl_color(fill_color().as_int());
fl_begin_complex_polygon();
for(int i=0; i<number_of_points(); ++i){
fl_vertex(point(i).x, point(i).y);
}
fl_end_complex_polygon();
fl_color(color().as_int()); // reset color
}
if (color().visibility())
Shape::draw_lines();
}
//------------------------------------------------------------------------------
void Closed_polyline::draw_lines() const
{
Open_polyline::draw_lines(); // first draw the "open poly line part"
// then draw closing line:
if (color().visibility())
fl_line(point(number_of_points()-1).x,
point(number_of_points()-1).y,
point(0).x,
point(0).y);
}
//------------------------------------------------------------------------------
void draw_mark(Point xy, char c)
{
static const int dx = 4;
static const int dy = 4;
string m(1,c);
fl_draw(m.c_str(),xy.x-dx,xy.y+dy);
}
//------------------------------------------------------------------------------
void Marked_polyline::draw_lines() const
{
Open_polyline::draw_lines();
for (int i=0; i<number_of_points(); ++i)
draw_mark(point(i),mark[i%mark.size()]);
}
//------------------------------------------------------------------------------
void Rectangle::draw_lines() const
{
if (fill_color().visibility()) { // fill
fl_color(fill_color().as_int());
fl_rectf(point(0).x,point(0).y,w,h);
}
if (color().visibility()) { // lines on top of fill
fl_color(color().as_int());
fl_rect(point(0).x,point(0).y,w,h);
}
}
//------------------------------------------------------------------------------
Circle::Circle(Point p, int rr) // center and radius
:r(rr)
{
add(Point(p.x-r,p.y-r)); // store top-left corner
}
//------------------------------------------------------------------------------
Point Circle::center() const
{
return Point(point(0).x+r, point(0).y+r);
}
//------------------------------------------------------------------------------
void Circle::draw_lines() const
{
if (color().visibility())
fl_arc(point(0).x,point(0).y,r+r,r+r,0,360);
}
//------------------------------------------------------------------------------
void Ellipse::draw_lines() const
{
if (color().visibility())
fl_arc(point(0).x,point(0).y,w+w,h+h,0,360);
}
//------------------------------------------------------------------------------
void Text::draw_lines() const
{
int ofnt = fl_font();
int osz = fl_size();
fl_font(fnt.as_int(),fnt_sz);
fl_draw(lab.c_str(),point(0).x,point(0).y);
fl_font(ofnt,osz);
}
//------------------------------------------------------------------------------
Axis::Axis(Orientation d, Point xy, int length, int n, string lab) :
label(Point(0,0),lab)
{
if (length<0) error("bad axis length");
switch (d){
case Axis::x:
{
Shape::add(xy); // axis line
Shape::add(Point(xy.x+length,xy.y));
if (1<n) { // add notches
int dist = length/n;
int x = xy.x+dist;
for (int i = 0; i<n; ++i) {
notches.add(Point(x,xy.y),Point(x,xy.y-5));
x += dist;
}
}
// label under the line
label.move(length/3,xy.y+20);
break;
}
case Axis::y:
{
Shape::add(xy); // a y-axis goes up
Shape::add(Point(xy.x,xy.y-length));
if (1<n) { // add notches
int dist = length/n;
int y = xy.y-dist;
for (int i = 0; i<n; ++i) {
notches.add(Point(xy.x,y),Point(xy.x+5,y));
y -= dist;
}
}
// label at top
label.move(xy.x-10,xy.y-length-10);
break;
}
case Axis::z:
error("z axis not implemented");
}
}
//------------------------------------------------------------------------------
void Axis::draw_lines() const
{
Shape::draw_lines();
notches.draw(); // the notches may have a different color from the line
label.draw(); // the label may have a different color from the line
}
//------------------------------------------------------------------------------
void Axis::set_color(Color c)
{
Shape::set_color(c);
notches.set_color(c);
label.set_color(c);
}
//------------------------------------------------------------------------------
void Axis::move(int dx, int dy)
{
Shape::move(dx,dy);
notches.move(dx,dy);
label.move(dx,dy);
}
//------------------------------------------------------------------------------
Function::Function(Fct f, double r1, double r2, Point xy,
int count, double xscale, double yscale)
// graph f(x) for x in [r1:r2) using count line segments with (0,0) displayed at xy
// x coordinates are scaled by xscale and y coordinates scaled by yscale
{
if (r2-r1<=0) error("bad graphing range");
if (count <=0) error("non-positive graphing count");
double dist = (r2-r1)/count;
double r = r1;
for (int i = 0; i<count; ++i) {
add(Point(xy.x+int(r*xscale),xy.y-int(f(r)*yscale)));
r += dist;
}
}
//------------------------------------------------------------------------------
bool can_open(const string& s)
// check if a file named s exists and can be opened for reading
{
ifstream ff(s.c_str());
return ff;
}
//------------------------------------------------------------------------------
#define ARRAY_SIZE(a) (sizeof(a)/sizeof((a)[0]))
Suffix::Encoding get_encoding(const string& s)
{
struct SuffixMap
{
const char* extension;
Suffix::Encoding suffix;
};
static SuffixMap smap[] = {
{".jpg", Suffix::jpg},
{".jpeg", Suffix::jpg},
{".gif", Suffix::gif},
};
for (int i = 0, n = ARRAY_SIZE(smap); i < n; i++)
{
int len = strlen(smap[i].extension);
if (s.length() >= len && s.substr(s.length()-len, len) == smap[i].extension)
return smap[i].suffix;
}
return Suffix::none;
}
//------------------------------------------------------------------------------
// somewhat over-elaborate constructor
// because errors related to image files can be such a pain to debug
Image::Image(Point xy, string s, Suffix::Encoding e)
:w(0), h(0), fn(xy,"")
{
add(xy);
if (!can_open(s)) { // can we open s?
fn.set_label("cannot open \""+s+'\"');
p = new Bad_image(30,20); // the "error image"
return;
}
if (e == Suffix::none) e = get_encoding(s);
switch(e) { // check if it is a known encoding
case Suffix::jpg:
p = new Fl_JPEG_Image(s.c_str());
break;
case Suffix::gif:
p = new Fl_GIF_Image(s.c_str());
break;
default: // Unsupported image encoding
fn.set_label("unsupported file type \""+s+'\"');
p = new Bad_image(30,20); // the "error image"
}
}
//------------------------------------------------------------------------------
void Image::draw_lines() const
{
if (fn.label()!="") fn.draw_lines();
if (w&&h)
p->draw(point(0).x,point(0).y,w,h,cx,cy);
else
p->draw(point(0).x,point(0).y);
}
//------------------------------------------------------------------------------
} // of namespace Graph_lib
我希望有人可以帮助我。
修改
/*
std_lib_facilities.h
*/
/*
simple "Programming: Principles and Practice using C++ (second edition)" course header to
be used for the first few weeks.
It provides the most common standard headers (in the global namespace)
and minimal exception/error support.
Students: please don't try to understand the details of headers just yet.
All will be explained. This header is primarily used so that you don't have
to understand every concept all at once.
By Chapter 10, you don't need this file and after Chapter 21, you'll understand it
Revised April 25, 2010: simple_error() added
Revised November 25 2013: remove support for pre-C++11 compilers, use C++11: <chrono>
Revised November 28 2013: add a few container algorithms
Revised June 8 2014: added #ifndef to workaround Microsoft C++11 weakness
*/
#ifndef H112
#define H112 251113L
#include<iostream>
#include<iomanip>
#include<fstream>
#include<sstream>
#include<cmath>
#include<cstdlib>
#include<string>
#include<list>
#include <forward_list>
#include<vector>
#include<unordered_map>
#include<algorithm>
#include <array>
#include <regex>
#include<random>
#include<stdexcept>
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
typedef long Unicode;
//------------------------------------------------------------------------------
using namespace std;
template<class T> string to_string(const T& t)
{
ostringstream os;
os << t;
return os.str();
}
struct Range_error : out_of_range { // enhanced vector range error reporting
int index;
Range_error(int i) :out_of_range("Range error: "+to_string(i)), index(i) { }
};
// trivially range-checked vector (no iterator checking):
template< class T> struct Vector : public std::vector<T> {
using size_type = typename std::vector<T>::size_type;
#ifdef _MSC_VER
// microsoft doesn't yet support C++11 inheriting constructors
Vector() { }
explicit Vector(size_type n) :std::vector<T>(n) {}
Vector(size_type n, const T& v) :std::vector<T>(n,v) {}
template <class I>
Vector(I first, I last) : std::vector<T>(first, last) {}
Vector(initializer_list<T> list) : std::vector<T>(list) {}
#else
using std::vector<T>::vector; // inheriting constructor
#endif
T& operator[](unsigned int i) // rather than return at(i);
{
if (i<0||this->size()<=i) throw Range_error(i);
return std::vector<T>::operator[](i);
}
const T& operator[](unsigned int i) const
{
if (i<0||this->size()<=i) throw Range_error(i);
return std::vector<T>::operator[](i);
}
};
// disgusting macro hack to get a range checked vector:
#define vector Vector
// trivially range-checked string (no iterator checking):
struct String : std::string {
using size_type = std::string::size_type;
// using string::string;
char& operator[](unsigned int i) // rather than return at(i);
{
if (i<0||size()<=i) throw Range_error(i);
return std::string::operator[](i);
}
const char& operator[](unsigned int i) const
{
if (i<0||size()<=i) throw Range_error(i);
return std::string::operator[](i);
}
};
namespace std {
template<> struct hash<String>
{
size_t operator()(const String& s) const
{
return hash<std::string>()(s);
}
};
} // of namespace std
struct Exit : runtime_error {
Exit(): runtime_error("Exit") {}
};
// error() simply disguises throws:
inline void error(const string& s)
{
throw runtime_error(s);
}
inline void error(const string& s, const string& s2)
{
error(s+s2);
}
inline void error(const string& s, int i)
{
ostringstream os;
os << s <<": " << i;
error(os.str());
}
template<class T> char* as_bytes(T& i) // needed for binary I/O
{
void* addr = &i; // get the address of the first byte
// of memory used to store the object
return static_cast<char*>(addr); // treat that memory as bytes
}
inline void keep_window_open()
{
cin.clear();
cout << "Please enter a character to exit\n";
char ch;
cin >> ch;
return;
}
inline void keep_window_open(string s)
{
if (s=="") return;
cin.clear();
cin.ignore(120,'\n');
for (;;) {
cout << "Please enter " << s << " to exit\n";
string ss;
while (cin >> ss && ss!=s)
cout << "Please enter " << s << " to exit\n";
return;
}
}
// error function to be used (only) until error() is introduced in Chapter 5:
inline void simple_error(string s) // write ``error: s and exit program
{
cerr << "error: " << s << '\n';
keep_window_open(); // for some Windows environments
exit(1);
}
// make std::min() and std::max() accessible on systems with antisocial macros:
#undef min
#undef max
// run-time checked narrowing cast (type conversion). See ???.
template<class R, class A> R narrow_cast(const A& a)
{
R r = R(a);
if (A(r)!=a) error(string("info loss"));
return r;
}
// random number generators. See 24.7.
inline int randint(int min, int max) { static default_random_engine ran; return uniform_int_distribution<>{min, max}(ran); }
inline int randint(int max) { return randint(0, max); }
//inline double sqrt(int x) { return sqrt(double(x)); } // to match C++0x
// container algorithms. See 21.9.
template<typename C>
using Value_type = typename C::value_type;
template<typename C>
using Iterator = typename C::iterator;
template<typename C>
// requires Container<C>()
void sort(C& c)
{
std::sort(c.begin(), c.end());
}
template<typename C, typename Pred>
// requires Container<C>() && Binary_Predicate<Value_type<C>>()
void sort(C& c, Pred p)
{
std::sort(c.begin(), c.end(), p);
}
template<typename C, typename Val>
// requires Container<C>() && Equality_comparable<C,Val>()
Iterator<C> find(C& c, Val v)
{
return std::find(c.begin(), c.end(), v);
}
template<typename C, typename Pred>
// requires Container<C>() && Predicate<Pred,Value_type<C>>()
Iterator<C> find_if(C& c, Pred p)
{
return std::find_if(c.begin(), c.end(), p);
}
#endif //H112
答案 0 :(得分：3)
错误C2440构建＆＃39;返回＆＃39;：无法转换为＆＃39; std :: ifstream＆＃39;到了布尔＆＃39; Win32Project1 C：\ Users \ Leonardo \ Documents \ Visual Studio 2015 \ Projects \ Win32Project1 \ Win32Project1 \ Graph.cpp 371
我怀疑你正在遇到C ++ 11引入的重大变革。代码似乎是这样的：
bool can_open(const string& s)
// check if a file named s exists and can be opened for reading
{
ifstream ff(s.c_str());
return ff;
}
以前使用operator void *将ff从istream投射到void *的代码可以投射到bool。如果ifstream是坏的，则转换为void *将导致空指针，而该指针又将被视为bool false。
但是C ++ 11为流引入了explicit operator bool()（并且摆脱了void *运算符？）。由于bool运算符为explicit，因此运算符不会用于隐式转换。
要让can_open使用C ++ 11版本的流进行编译，您需要使转换显式：
bool can_open(const string& s)
// check if a file named s exists and can be opened for reading
{
ifstream ff(s.c_str());
return (bool)ff;
}
但是，如果使用pre-C ++ 11版本的流编译，则该更改将破坏代码。