VB 贪吃蛇 单人版游戏 （原作）[4]

                p1.y_way = 0
            end if
        case key_lfdn
            blnonkeyevents = false
            if p1.x_way <> 0 then
                p1.x_way = 0
                p1.y_way = 1
            elseif p1.y_way <> 0 then
                p1.x_way = -1
                p1.y_way = 0
            end if
       
        case key_rtup
            blnonkeyevents = false
            if p1.x_way <> 0 then
                p1.x_way = 0
                p1.y_way = -1
            elseif p1.y_way <> 0 then
                p1.x_way = 1
                p1.y_way = 0
            end if
        case key_rtdn
            blnonkeyevents = false
            if p1.x_way <> 0 then
                p1.x_way = 0
                p1.y_way = 1
            elseif p1.y_way <> 0 then
                p1.x_way = 1
                p1.y_way = 0
            end if
       
    '当蛇以 水平 方向移动时，lf 和 rt 按键无效
        case key_lf
            blnonkeyevents = false
            if p1.x_way = 0 then
                p1.x_way = -1
                p1.y_way = 0
            end if
        case key_rt
            blnonkeyevents = false
            if p1.x_way = 0 then
                p1.x_way = 1
                p1.y_way = 0
            end if
       
    '当蛇以 垂直 方向移动时，up 和 dn 按键无效
        case key_up
            blnonkeyevents = false
            if p1.y_way = 0 then
                p1.x_way = 0
                p1.y_way = -1
            end if
        case key_dn
            blnonkeyevents = false
            if p1.y_way = 0 then
                p1.x_way = 0