Linux 终端不显示任何带有 ncurses 的内容

Question

我正在尝试创建一个库来简化 ncurses 用于显示颜色的过程。我正在做面向对象的工作，因此将来可以轻松处理更改。但问题是我无法使用这段代码。

#include <ncurses.h>
#include <string.h> 
#include <string>
#include <unistd.h>
#include <iostream>

using namespace std;

class ColorWindow {
    private:
        bool canColor;
        WINDOW* container;
        int height, width, startx, starty;

    public:
        ColorWindow() {
            if(has_colors()) {
                canColor=true;
            }

            this->height = 20;
            this->width = 84;
            this->starty = (LINES - height) / 2;    /* Calculating for a center placement */
            this->startx = (COLS - width) / 2;
        }

        bool writeStringWithColor(int x, int y, const char* message) {
            if(!canColor) {
                writeString(3, 5, "Sorry, your term can't show colors.");
                return false;
            }

            init_pair(1, COLOR_RED, COLOR_BLACK);

            writeString(0, 10, "aaaaaaaaa");

            wattron(getContainer(), COLOR_PAIR(1));
            writeString(x, y, message);
            wattroff(getContainer(), COLOR_PAIR(1));
        }

        void writeString(int x, int y, const char* message) {
            mvwprintw(getContainer(), x, y, message);
        }

        WINDOW* createNewContainer() {
            this->container = newwin(height, width, starty, startx);
            wrefresh(this->container);      /* Show that box        */

            return getContainer();
        }

        WINDOW* getContainer() {
            return this->container;
        }

        void refreshContainer() {
            refresh();
            wrefresh(this->container);      /* Show that box        */
        }       
};

int main() {
    ColorWindow cw = ColorWindow();


    initscr();          /* Start curses mode        */
    cbreak();           /* Line buffering disabled, Pass on
                        * everything to me      */
    keypad(stdscr, TRUE);
    start_color();

    cw.createNewContainer();

    bool success = cw.writeStringWithColor(0, 10, "Hello everyone in color!!");
    if(!success)
        cw.writeString(0, 10, "Write with color failed :(");
    cw.refreshContainer();
    sleep(2);
    endwin();

    return 0;
}

提前致谢。

Answer 1

您的代码中有几个错误：

• 您没有初始化canColor 和container，因此将字段复制到main 中的cw 具有未定义的行为。修复者：

  ColorWindow() : canColor(false), container(nullptr) {
  

• writeStringWithColor 在末尾缺少 return 语句，这也会导致 main 中的未定义行为。修复者：

  return true;
  

  writeStringWithColor 结尾。

• 您的x 和y 参数在writeString 中对mvwprintw 的调用中交换。修复者：

  mvwprintw(getContainer(), y, x, message);
  

• LINES 和 COLS 仅在 ncurses 初始化后有效，因此您的 starty 和 startx 值是垃圾。通过将 cw 的初始化移动到 main 中的 ncurses 初始化代码之后来修复：

  initscr();          /* Start curses mode        */
  cbreak();           /* Line buffering disabled, Pass on
                      * everything to me      */
  keypad(stdscr, TRUE);
  start_color();
  
  ColorWindow cw = ColorWindow();
  

---

完整程序：

#include <ncurses.h>
#include <string.h> 
#include <string>
#include <unistd.h>
#include <iostream>

using namespace std;

class ColorWindow {
    private:
        bool canColor;
        WINDOW* container;
        int height, width, startx, starty;

    public:
        ColorWindow() : canColor(false), container(nullptr) {
            if(has_colors()) {
                canColor=true;
            }

            this->height = 20;
            this->width = 84;
            this->starty = (LINES - height) / 2;    /* Calculating for a center placement */
            this->startx = (COLS - width) / 2;
        }

        bool writeStringWithColor(int x, int y, const char* message) {
            if(!canColor) {
                writeString(3, 5, "Sorry, your term can't show colors.");
                return false;
            }

            init_pair(1, COLOR_RED, COLOR_BLACK);

            writeString(0, 10, "aaaaaaaaa");

            wattron(getContainer(), COLOR_PAIR(1));
            writeString(x, y, message);
            wattroff(getContainer(), COLOR_PAIR(1));
            return true;
        }

        void writeString(int x, int y, const char* message) {
            mvwprintw(getContainer(), y, x, message);
        }

        WINDOW* createNewContainer() {
            this->container = newwin(height, width, starty, startx);
            wrefresh(this->container);      /* Show that box        */

            return getContainer();
        }

        WINDOW* getContainer() {
            return this->container;
        }

        void refreshContainer() {
            refresh();
            wrefresh(this->container);      /* Show that box        */
        }       
};

int main() {
    initscr();          /* Start curses mode        */
    cbreak();           /* Line buffering disabled, Pass on
                        * everything to me      */
    keypad(stdscr, TRUE);
    start_color();

    ColorWindow cw = ColorWindow();

    cw.createNewContainer();

    bool success = cw.writeStringWithColor(0, 10, "Hello everyone in color!!");
    if(!success)
        cw.writeString(0, 10, "Write with color failed :(");
    cw.refreshContainer();
    sleep(2);
    endwin();

    return 0;
}