Question

我希望按钮的回调方法在每次单击按钮时实例化一个窗口（使用编辑器），这可能导致多个窗口同时显示编辑器。现在我很高兴只出现一个-不会出现。

也欢迎对一般FLTK和C ++编程实践发表评论。

#include <FL/Fl.H> 
#include <FL/Fl_Window.H>
#include <FL/Fl_Button.H>
#include <FL/Fl_Text_Editor.H>
#include <FL/Fl_Text_Buffer.H>

class MainWin : public Fl_Window {

    public:
        MainWin(int w, int h, const char *title);
        ~MainWin();
        Fl_Button* gobtn;
        Fl_Text_Editor* ed; // first editor included with main window
        Fl_Text_Buffer* buf;
    private:
        static void gomthd(Fl_Widget *, void *);        // "go" method
};

class AdditionalWin : public Fl_Window {   // more editors if necessary
    public:
        AdditionalWin(int w, int h, const char *title);
        ~AdditionalWin();
        Fl_Text_Editor *ed;
        Fl_Text_Buffer *buf;
};

int main () {
    MainWin win(105, 405, "main");
    return Fl::run();
}

MainWin::MainWin(int w, int h, const char* title):Fl_Window(w,h,title) {

    gobtn = new Fl_Button(8, 38, 35, 20, "go");
    gobtn->callback(gomthd, this);

    ed = new Fl_Text_Editor(6, 67, 93, 331);
    buf = new Fl_Text_Buffer();
    ed->buffer(buf);

    end();
    resizable(this);
    show();
}

AdditionalWin::AdditionalWin(int w, int h, const char *title):Fl_Window(w, h, title) {

    ed = new Fl_Text_Editor(6, 67, 93, 331);
    buf = new Fl_Text_Buffer();
    ed->buffer(buf);
    end();
    resizable(this);
    show();

}

void MainWin::gomthd(Fl_Widget* o, void* v) {

    AdditionalWin awin(105, 405, "more");
    awin.position(1, 1);
    awin.show();          // ??? nothing appears
}

MainWin::~MainWin(){}
AdditionalWin::~AdditionalWin(){}

Answer 1

到晚会很晚，但是仍然：我认为新窗口永远不会显示，因为awin作为一个局部变量，在MainWin :: gomthd（）函数返回时就被销毁了。

为什么此窗口不出现

1 个答案: