布局就是定义如何排列小部件
PageLayout：滑页布局
https://kivy.org/doc/stable/api-kivy.uix.pagelayout.html
from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.pagelayout import PageLayout
class ExamplePageLayout(PageLayout):
def __init__(self, **kwargs):
super(ExamplePageLayout, self).__init__(**kwargs)
# 创建部件
btn1 = Button(text='Hello', background_color=[0, 0, 1, 1])
btn2 = Button(text='World', background_color=[0, 1, 0, 1])
btn3 = Button(text='Hi', background_color=[0, 1, 1, 1])
btn4 = Button(text='Kivy', background_color=[1, 0, 0, 1])
btn5 = Button(text='你好', background_color=[1, 0, 1, 1])
btn6 = Button(text='中国', background_color=[1, 1, 0, 1])
# 添加部件
self.add_widget(btn1)
self.add_widget(btn2)
self.add_widget(btn3)
self.add_widget(btn4)
self.add_widget(btn5)
self.add_widget(btn6)
class MyApp(App):
def build(self):
return ExamplePageLayout(anim_kwargs = {'d': 5, 't': 'in_quad'}, border = 100, swipe_threshold = .2)
def on_stop(self):
print('应用程序已关闭')
if __name__ == '__main__':
MyApp().run()
代码解释
Page Layout 就是实现手机上常见的滑动翻页效果
anim_kwargs = {'d': 5, 't': 'in_quad'}
其中：
'd'代表动画的持续时间，5 代表动画持续5秒
't'代表动画的插值类型，in_quad 表示动画先慢后快
该参数默认值是 {‘d’: .5, ‘t’: ‘in_quad’}
具体还有哪些插值类型，可以通过引用 <class 'kivy.animation.AnimationTransition'> 查看
border = 100
表示可以按住滑动页面的边框宽度，下图右侧绿色部分
该参数默认值是 50像素
swipe_threshold = .2
表示触发滑动的阈值，.2 表示按住滑动超过页面20%宽度，即可松开由其自动继续滑动到下一页
该参数的默认值是 .5
以上代码执行效果如下
PageLayout01.JPG
修改代码如下
我们还可以获取触摸屏幕 按下，移动，松开时的坐标信息
class ExamplePageLayout(PageLayout):
......
# 触摸-按下
def on_touch_down(self, touch):
print('+ on_touch_down, the spos value is {}, the pos value is {}'.format(touch.spos, touch.pos))
super().on_touch_down(touch) # 保留默认的触摸事件处理
# 触摸-移动
def on_touch_move(self, touch):
print('+ on_touch_move, the spos value is {}, the pos value is {}'.format(touch.spos, touch.pos))
super().on_touch_move(touch) # 保留默认的触摸事件处理
# 触摸-松开
def on_touch_up(self, touch):
print('+ on_touch_up, the spos value is {}, the pos value is {}'.format(touch.spos, touch.pos))
super().on_touch_up(touch) # 保留默认的触摸事件处理
touch.spos 是相对位置，以x轴和y轴为基准，输出距离x，y轴的距离（0~1）
touch.pos 是绝对位置，以左上角为原点，输出 x，y 值
需要使用 super().on_touch_down(touch) 等来保留默认的触摸事件处理，否则会阻止页面的滑动
+ on_touch_down, the spos value is (0.918648310387985, 0.5008347245409015), the pos value is (734.0, 300.0)
+ on_touch_move, the spos value is (0.9173967459324155, 0.5008347245409015), the pos value is (733.0, 300.0)
+ on_touch_move, the spos value is (0.9173967459324155, 0.5008347245409015), the pos value is (733.0, 300.0)
+ on_touch_move, the spos value is (0.9161451814768461, 0.5008347245409015), the pos value is (732.0, 300.0)
+ on_touch_move, the spos value is (0.9161451814768461, 0.5008347245409015), the pos value is (732.0, 300.0)
+ on_touch_move, the spos value is (0.9136420525657072, 0.5008347245409015), the pos value is (730.0, 300.0)
+ on_touch_move, the spos value is (0.9136420525657072, 0.5008347245409015), the pos value is (730.0, 300.0)
+ on_touch_up, the spos value is (0.9136420525657072, 0.5008347245409015), the pos value is (730.0, 300.0)
+ on_touch_up, the spos value is (0.9136420525657072, 0.5008347245409015), the pos value is (730.0, 300.0)
