我是首发。我有个主意。我想实现这样的事件。有可能吗？
<html>
<head>
<title>First visit event</title>
<script>
function do_something()
{
alert("Hello my friend. This is your first visit.");
}
</script>
</head>
<body firstVisitEvent="do_something()">
</body>
答案 0 :(得分：2)
在负载时使用。它将在页面加载时执行，您将看到警报。祝你好运。
<html>
<head>
<script>
function load()
{
alert("Page is loaded");
}
</script>
</head>
<body onload="load()">
<h1>Hello World!</h1>
</body>
</html>
编辑：您可以获得更多预付款并设置Cookie，看看它是否是用户的第一次，但我不确定您是否处于该级别，但无论如何：
例如，您可以设置类似
的localStorage属性if(!localStorage["alertdisplayed"]) {
alert("Your text")
localStorage["alertdisplayed"] = true
}
请注意旧浏览器不支持localStorage。
另一种方法是设置Cookie并检查其存在
如果您不知道如何使用javascript设置/获取Cookie，我建议您阅读这篇文章：https://developer.mozilla.org/en-US/docs/Web/API/document.cookie?redirectlocale=en-US&redirectslug=DOM%2Fdocument.cookie
答案 1 :(得分：2)
Localstorage可能是要走的路。以下是一些信息：http://diveintohtml5.info/storage.html
基本上它允许您在用户的计算机上存储少量数据（在大多数浏览器中最多可以存储5mb）。所以你需要做的是在那里设置一个标志，让你知道用户已经访问过，如果页面加载时没有该标志，则显示消息。
// Run function on load, could also run on dom ready
window.onload = function() {
// Check if localStorage is available (IE8+) and make sure that the visited flag is not already set.
if(typeof window.localStorage !== "undefined" && !localStorage.getItem('visited')) {
// Set visited flag in local storage
localStorage.setItem('visited', true);
// Alert the user
alert("Hello my friend. This is your first visit.");
}
}
这适用于所有可用本地存储的浏览器。请参阅caniuse.com以供参考。 http://caniuse.com/#search=localstorage
答案 2 :(得分：1)
您有几个选择：在客户端存储cookie或使用html5的本地存储。可以在页面加载时检查其中任何一个。
以下是HTML5网络存储入门的链接：
答案 3 :(得分：1)
你可以通过以下方式为chrome做到这一点
<html>
<head>
<title>First visit event</title>
<script>
function do_something() {
if(typeof(localStorage.setVisit)=='undefind' || localStorage.setVisit==''){
localStorage.setVisit='yes';
alert("Hello my friend. This is your first visit.");
}
}
</script>
</head>
<body onload="do_something()"> </body>
答案 4 :(得分：0)
由于操作符和函数名称的原因，使用localStorage可能很繁琐，为简化起见，可以使用in运算符检查键是否存在：
import sys
class TextsObjects:
def __init__(self):
self.setting = Settings()
self.intro_settings = IntroSettings()
self.display_intro_1 = DisplayText(
self.intro_settings.intro_text_1,
self.intro_settings.intro_text_1_pos_x,
self.intro_settings.intro_text_1_pos_y,
self.intro_settings.font_size,
self.setting.light_grey
)
self.display_intro_2 = DisplayText(
self.intro_settings.intro_text_2,
self.intro_settings.intro_text_2_pos_x,
self.intro_settings.intro_text_2_pos_y,
self.intro_settings.font_size,
self.setting.light_grey
)
self.display_intro_title = DisplayText(
self.intro_settings.intro_text_title,
self.intro_settings.intro_text_title_pos_x,
self.intro_settings.intro_text_title_pos_y,
self.intro_settings.font_size,
self.setting.light_grey)
class Intro:
def __init__(self, screen, setting):
self.screen = screen
self.setting = setting
self.i_setting = IntroSettings()
self.intro_text = TextsObjects()
self.clock = pygame.time.Clock()
self.speed = 150 * setting.time
print(self.speed)
self.screen_c_left = setting.screen_width / 2 - self.speed / 2
self.screen_c_right = setting.screen_width / 2 + self.speed / 2
def intro_update(self):
# reset the background so you don't get multiple drawings onscreen
self.screen.fill(self.setting.dark_blueish)
if 0 <= self.i_setting.intro_text_1_pos_x <= self.setting.screen_width:
# Draw the first text
self.intro_text.display_intro_1.draw_me_with_shadow(self.screen)
if self.screen_c_left < self.i_setting.intro_text_2_pos_x < self.screen_c_right:
# Draw the second text
self.intro_text.display_intro_2.draw_me_with_shadow(self.screen)
pygame.display.update()
def show_intro(self):
#self.i_setting.intro_text_1_pos_x += self.speed
# show the intro for self.intro_time amount of time
for frames in range(0, self.setting.fps * 3):
# test for events
for event in pygame.event.get():
print(event)
# when the window is closed stop the game loop
if event.type == pygame.QUIT:
sys.exit()
#self.i_setting.intro_text_1_pos_x += self.speed
self.intro_text.display_intro_1.text_rect.x += self.speed
self.intro_text.display_intro_1.text_rect_shadow.x += self.speed
self.intro_update()
self.setting.clock.tick(self.setting.fps)
class Settings:
def __init__(self):
# screen size
self.screen_width = 800
self.screen_height = 500
# set clock and fps
self.clock = pygame.time.Clock()
self.fps = 60
# calculate the seconds in every frame
self.time = 1 / self.fps
self.light_grey = (128,128,128)
self.dark_blueish = (0,0,255)
class IntroSettings:
def __init__(self):
self.setting = Settings()
self.font_size = 100
self.timer_font_size = 10
self.intro_text_1_pos_x = (self.setting.screen_width / 2) - 100
self.intro_text_1_pos_y = \
(self.setting.screen_height / 2 - self.font_size)
self.intro_text_1 = "A game by:"
self.intro_text_2_pos_x = (self.setting.screen_width / 2)
self.intro_text_2_pos_y = \
(self.setting.screen_height / 2 + self.font_size)
self.intro_text_2 = "Mark Olieman"
self.intro_text_title_pos_x = (self.setting.screen_width / 2)
self.intro_text_title_pos_y = (self.setting.screen_height + self.font_size)
self.intro_text_title = "Alien Invasion!"
self.intro_text_timer_pos_x = 20
self.intro_text_timer_pos_y = 20
self.speed = -2
class DisplayText:
def __init__(self, text, pos_x, pos_y, font_size, text_color):
self.font = pygame.font.Font("freesansbold.ttf", font_size)
self.text_surf = self.font.render(text, True, text_color)
self.text_rect = self.text_surf.get_rect()
self.text_rect.center = (pos_x, pos_y)
self.shadow_color = (0, 0, 0)
self.text_surf_shadow = self.font.render(text, True, self.shadow_color)
self.text_rect_shadow = self.text_surf.get_rect()
self.text_rect_shadow.center = (pos_x + 10, pos_y + 5)
def draw_me(self, screen):
screen.blit(self.text_surf, self.text_rect)
def draw_me_with_shadow(self, screen):
screen.blit(self.text_surf_shadow, self.text_rect_shadow)
screen.blit(self.text_surf, self.text_rect)
import pygame
#from Entities import *
#from Game_functions import *
#from Menu import *
# initizialize pygame
pygame.init()
pygame.mixer.init()
# make the modules available
setting = Settings()
screen = pygame.display.set_mode((setting.screen_width, setting.screen_height))
pygame.display.set_caption("Alien Invasion, By Mark Olieman")
intro = Intro(screen, setting)
#player = Player(screen, setting)
#bullet = Bullet(screen, setting, player)
intro_set = IntroSettings()
# initizialize the screen and set a caption
# function to start gaming
def gaming():
bullets = pygame.sprite.Group()
intro.show_intro()
intro_set.intro_text_1_pos_x += intro.speed
print(intro_set.intro_text_1_pos_x)
# Game Loop
while True:
# check events and make actions happen
#events(bullets, player, screen, setting)
# update everything and draw bullets
#update(player, setting, bullets, screen)
# update screen at certain fps
pygame.display.update()
setting.clock.tick(setting.fps)
# Start the game
gaming()
# Stop the game
pygame.quit()