AttributeError:“按钮"对象没有属性"update_label". [英] AttributeError: 'Button' object has no attribute 'update_label'.
问题描述
我坚持使用我的代码，请您帮忙吗?在将on_press添加到我的kv文件并描述了函数update_label之后，出现了错误:
AttributeError: 'Button' object has no attribute 'update_label'.
即使我使用简单的print()函数更改了对函数的描述，它也不起作用.预先感谢！
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.lang import Builder
from kivy.uix.button import Button
from kivy.uix.label import Label
from kivy.uix.stacklayout import StackLayout
from kivy.uix.textinput import TextInput
Builder.load_file('spain2.kv')
class Box2(BoxLayout):
pass
class Box1(StackLayout):
pass
class Ex42App(App):
def update_label(self):
if self.l1.text == 'amar':
self.l2.text = "Translate: to love"
else:
self.l2.text = "Infinitive not founded"
def build(self):
return Box2()
if __name__=='__main__':
Ex42App().run()
spain2.kv:
<Box2>:
orientation: 'vertical'
Box1:
orientation: 'lr-tb'
size_hint: 1, .1
Label:
id: l1
text: 'Insert Infinitive'
size_hint: None, None
size: 150, 30
TextInput:
size_hint: None, None
size: 300, 30
Button:
text: 'Find'
size_hint: None, None
size: 150, 30
on_press: self.update_label
Label:
id: l2
text: 'some data'
size_hint: None, .9
似乎他不知道.kv中self，root和app的含义，在这种情况下，请考虑以下代码:
<A>:
property_a: self.a
property_a1: root.a1
B:
property_b: self.b
property_c1: root.b1
C:
property_c: self.c
property_c1: root.c1
在观察到.kv语言时，它是声明性的，并且有一个层次结构树.
在这种情况下，root引用第一个元素:<A>.
相反，self引用树中的元素，如果self.a引用属性a属于A，如果self.c引用属性c属于C.
在app的情况下，是指属于从App继承的类的对象，并且此对象是唯一的，在您的案例中，app的情况是指从Ex42App继承的对象Ex42App().
因此root和self是相对于层次结构树的，例如，我们可以放置一个更复杂的结构:
<A>:
B:
some_property1: self.a # self is B
some_property2: root.a # root is A
<Y>:
Z:
some_property1: self.a # self is Z
some_property2: root.a # root is Y
根据上面的代码，我们分析了您的情况，根据您的代码说update_label属于Button，但这是不正确的，它属于App，因此，另一方面，您必须使用app update_label是一个函数，因此您必须使用()调用它.
另一方面，代码.py指出l1和l2属于App，但这不属于App而是Box2，但属于l1和l2仅在Box2内部可见，因此可以在Box之外使用它，您必须将它们公开为属性，最后Box2是返回build()的小部件，并且可以通过self.root访问该元素. /p>
考虑到上述情况，解决方案是:
*.py
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.lang import Builder
from kivy.uix.stacklayout import StackLayout
Builder.load_file('spain2.kv')
class Box2(BoxLayout):
pass
class Box1(StackLayout):
pass
class Ex42App(App):
def update_label(self):
if self.root.l1.text == 'amar': # <--
self.root.l2.text = "Translate: to love" # <--
else:
self.root.l2.text = "Infinitive not founded" # <--
def build(self):
return Box2()
if __name__=='__main__':
Ex42App().run()
*.kv
<Box2>:
l1: l1 # <--
l2: l2 # <--
orientation: 'vertical'
Box1:
orientation: 'lr-tb'
size_hint: 1, .1
Label:
id: l1
text: 'Insert Infinitive'
size_hint: None, None
size: 150, 30
TextInput:
size_hint: None, None
size: 300, 30
Button:
text: 'Find'
size_hint: None, None
size: 150, 30
on_press: app.update_label() # <--
Label:
id: l2
text: 'some data'
size_hint: None, .9
I am stuck with my code, could you please help? After I added on_press to my kv file and describe function update_label, I got error:
AttributeError: 'Button' object has no attribute 'update_label'.
Even if i change description of my function with simple print() function it doesn't works. Thanks in advance!
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.lang import Builder
from kivy.uix.button import Button
from kivy.uix.label import Label
from kivy.uix.stacklayout import StackLayout
from kivy.uix.textinput import TextInput
Builder.load_file('spain2.kv')
class Box2(BoxLayout):
pass
class Box1(StackLayout):
pass
class Ex42App(App):
def update_label(self):
if self.l1.text == 'amar':
self.l2.text = "Translate: to love"
else:
self.l2.text = "Infinitive not founded"
def build(self):
return Box2()
if __name__=='__main__':
Ex42App().run()
spain2.kv:
<Box2>:
orientation: 'vertical'
Box1:
orientation: 'lr-tb'
size_hint: 1, .1
Label:
id: l1
text: 'Insert Infinitive'
size_hint: None, None
size: 150, 30
TextInput:
size_hint: None, None
size: 300, 30
Button:
text: 'Find'
size_hint: None, None
size: 150, 30
on_press: self.update_label
Label:
id: l2
text: 'some data'
size_hint: None, .9
It seems that he does not know the meaning of self, root and app inside a .kv, for this case consider the following code:
<A>:
property_a: self.a
property_a1: root.a1
B:
property_b: self.b
property_c1: root.b1
C:
property_c: self.c
property_c1: root.c1
As the language .kv is observed, it is declarative and there is a tree of hierarchy.
In this case the root refers to the first element: <A>.
Instead the self refers to an element within the tree, in the case of self.a refers to the property a belongs to A, in the case of self.c refers to the property c belongs to C.
And in the case of app refers refers to the object that belongs to a class that inherits from App, and this object is unique, in your case app refers to the object Ex42App() that inherits from Ex42App.
So root and self is relative to a hierarchy tree, for example we can place a more complex structure:
<A>:
B:
some_property1: self.a # self is B
some_property2: root.a # root is A
<Y>:
Z:
some_property1: self.a # self is Z
some_property2: root.a # root is Y
With the above we analyze your case, according to what your code says update_label belongs to the Button but that is not correct, it belongs to App so you must use app, on the other hand update_label is a function so you must invoke it using ().
On the other hand in the code .py point out that l1 and l2 belongs to App but this does not belong to App but to Box2, but l1 and l2 is only visible inside Box2, so that it can be used outside of Box you must expose them as properties, and finally Box2 is the widget that returns build() and that element is accessed through self.root.
Considering the above, the solution is:
*.py
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.lang import Builder
from kivy.uix.stacklayout import StackLayout
Builder.load_file('spain2.kv')
class Box2(BoxLayout):
pass
class Box1(StackLayout):
pass
class Ex42App(App):
def update_label(self):
if self.root.l1.text == 'amar': # <--
self.root.l2.text = "Translate: to love" # <--
else:
self.root.l2.text = "Infinitive not founded" # <--
def build(self):
return Box2()
if __name__=='__main__':
Ex42App().run()
*.kv
<Box2>:
l1: l1 # <--
l2: l2 # <--
orientation: 'vertical'
Box1:
orientation: 'lr-tb'
size_hint: 1, .1
Label:
id: l1
text: 'Insert Infinitive'
size_hint: None, None
size: 150, 30
TextInput:
size_hint: None, None
size: 300, 30
Button:
text: 'Find'
size_hint: None, None
size: 150, 30
on_press: app.update_label() # <--
Label:
id: l2
text: 'some data'
size_hint: None, .9
这篇关于AttributeError:“按钮"对象没有属性"update_label".的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
