我有一个使用ncurses(C)读取表单字段的代码,但是当表单字段未完全键入时我无法显示值.

#include <form.h>
#include <curses.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

WINDOW *chatwin, *entrywin;
FIELD  *field[1];
FORM   *fo;

void quit(void)
{
    int i;
    unpost_form(fo);
    free_form(fo);

    free_field(field[0]);
    free_field(field[1]);

    delwin(chatwin);
    endwin();
}

int main(void)
{
    int xsize, ysize;
    int charinput, i;
    char inputstring[200];
    char ttime[10];
    initscr();
    atexit(quit);
    clear();
    noecho();
    curs_set(1);
    cbreak();
    keypad(stdscr, TRUE);

    getmaxyx(stdscr, ysize, xsize);

    start_color();
    use_default_colors();
    init_pair(1, COLOR_YELLOW, COLOR_BLUE);
    init_pair(2, COLOR_BLUE, COLOR_WHITE);

    chatwin = newwin((ysize - 8), (xsize-21), 6, 21);

    entrywin = newwin(1, (xsize-21), (ysize - 1), 21);

    field[0] = new_field(1, (xsize - 21), 0, 0, 0, 10);
    field[1] = 0;
    set_form_win(fo, entrywin);
    fo = new_form(field);
    post_form(fo); 
    field_opts_on(field[0], O_STATIC);
    set_field_fore(field[0], COLOR_PAIR(2));
    set_field_back(field[0], COLOR_PAIR(2));

    refresh();
    wrefresh(chatwin);
    wrefresh(entrywin);

    while((charinput=getch()) != KEY_END)
    {
        switch(charinput)
        {
            case 10:
                snprintf(inputstring, 200, "%s", field_buffer(field[0], 0));
                struct tm *akttime;
                time_t second;
                time(&second);
                akttime = localtime(&second);
                strftime(ttime, 10, "%H:%M:%S", akttime);
                wprintw(chatwin, "<%s> %s|\n", ttime, inputstring);
                wrefresh(chatwin);
                set_field_buffer(field[0], 0, "");
                wrefresh(entrywin);
                break;

            default:
                form_driver(fo, charinput);
                wrefresh(entrywin);
        }
    } 

    return(0);
}

OUTPUT

观察：第二行键入：ejheeh,但是输出为空

<02:31:42> dddddddkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk
                     kkkkkkkkkkk|

<02:31:45>
                                |

<02:31:51> ddddddddddddddddddddddddddddddddddddddddddddddddddddfffffff
                     fffffffffff|

解决方法:

通常,ncurses表单库在离开字段之前不会同步字段缓冲区.由于您尝试在离开字段之前读取缓冲区,因此缓冲区没有当前内容.

强制缓冲区同步而不实际移动到下一个字段的简单方法是强制字段验证-这将同步并运行任何验证功能.

在案例10的开头添加以下行：

form_driver(fo, REQ_VALIDATION);

您可能要检查验证错误：

if (form_driver(fo, REQ_VALIDATION) != E_OK) {
    // do something
}