框内的 Ncurses 文本在刷新时闪烁

Question

我正在尝试在一些将要更新的文本周围画一个框。在占位符中，文本是静态的，但仍然可以观察到闪烁。我的代码如下

 /*
 * @file main.cc
 * @author Tom Eaton
 * @date 09 Jan 2018
 * @brief Command line interface to show Hawkcell PCB data.
 */
#include <iostream>
#include <string>
#include <cstring>
#include <ncurses.h>

using namespace std;
/*
 * Prints string in the horizontal center of row specified.
 * @param row - Row that text should be printed on
 * @param mesg - Pointer to char array containing message
 */
void printHorizCenter(int row, char* mesg) {
        mvprintw(row, ((COLS - strlen(mesg))/2)-1, mesg);
}

/*
 * Reads version of PCB and updates char array with version
 * @param outVersion - Pointer to char array where version should be stored.
 * @param port - Reference to serial port
 */
void printHorizBlock(int row, int startCol, int endCol) {
        for(int i = startCol; i<=endCol; i++) {
                mvaddch(row, i, ACS_BLOCK);
        }
}

int main(int argc, char** argv) {
        //Initialise curses
        initscr();
        cbreak();
        echo();
        keypad(stdscr, 1);

        //Make character capture non blocking
        nodelay(stdscr, 1);

        //Define char arrays for each cell
        char cellOne[2] = {'1', '\n'};
        char cellTwo[2] = {'2', '\n'};
        char cellThree[2] = {'3', '\n'};
        char cellFour[2] = {'4', '\n'};

        //Setup curses colour schemes
        start_color();
        use_default_colors();
        curs_set(0);

        //Setup curses colour pairs
        init_pair(1, COLOR_RED, -1);
        init_pair(2, COLOR_WHITE, COLOR_RED);

        WINDOW *win = newwin(10, 20, 1, 0);


        //Main loop
        while (1) {
                if(getch() == 12) {
                        endwin();
                        cerr << "You pressed left and exited" << endl;
                        exit(1);
                }
                //Print top title bar
                attron(COLOR_PAIR(1));
                printHorizBlock(0, 0, (COLS/2) - (strlen("HawkCell")/2));
                attroff(COLOR_PAIR(1));
                attron(COLOR_PAIR(2));
                printHorizCenter(0, (char *)"HawkCell");
                attroff(COLOR_PAIR(2));
                attron(COLOR_PAIR(1));
                printHorizBlock(0, (COLS/2) + (strlen("HawkCell")/2) - 1, COLS);
                attroff(COLOR_PAIR(1));


                //Print voltage data
                mvprintw(3, 1, "Cell 1: %.3fV\n", 4.0f);
                mvprintw(4, 1, "Cell 2: %.3fV\n", 4.0f);
                mvprintw(5, 1, "Cell 3: %.3fV\n", 4.0f);
                mvprintw(6, 1, "Cell 4: %.3fV\n", 4.0f);
                mvprintw(7, 1, "Total: %.3fV\n", 4.0f);

                //Print bottom info bar
                attron(COLOR_PAIR(1));
                printHorizBlock(LINES-1, 0, COLS);
                attroff(COLOR_PAIR(1));
                attron(COLOR_PAIR(2));
                printHorizCenter(LINES-1, (char *)"ctrl+c: Exit, ctrl+l: Toggle logging ");
                attroff(COLOR_PAIR(2));

                //Call curses refresh function to update screen
                box(win, 0, 0);
                //touchwin(win);
                wrefresh(win);
                wrefresh(stdscr);
        }

        getch();
        endwin();
        return 0;
}

问题是屏幕重绘时出现闪烁，如下图gif所示（感光警告）Gif showing problem。如您所见，它只发生在包含文本的行上，这让我觉得在编写文本时正在绘制整条线，而不仅仅是特定字符。

我试过使用 wrefresh()、touchwin()、erase() 和 refresh() 的各种组合，但我找不到任何不产生闪烁的组合。

如何停止这种闪烁？

Answer 1

问题是您对 stdscr 和 win 的更新交替更新 当前屏幕 (curscr)，并且由于它们写在同一个区域，他们正在重画很多。

您可以通过创建 win 的子window 并使用 that window 来编写文本来改进这一点。

类似

WINDOW *txt = derwin(win, 8, 18, 1, 1);

... 使用 stdscr:

修改所有调用

mvwprintw(txt, 7, 1, "Total: %.3fV\n", 4.0f);

//Print bottom info bar
wattron(txt, COLOR_PAIR(1));

并使用 wgetch(txt) 而不是 getch() 来获取字符。该框只需要刷新一次（在循环之前），并且 wgetch() 无论如何都会刷新 window：移除最后一个 wrefresh 并在创建 win 之后移动另一个并调用 box:

WINDOW *win = newwin(10, 20, 1, 0);
box(win, 0, 0);
wrefresh(win);

框内的 Ncurses 文本在刷新时闪烁

Ncurses text inside box flickering on refresh

c

ncurses

command-line-interface