問題描述
我有一個套接字客戶端，它每次收到消息時都會調用 View() 類.我已經以這樣一種方式拆分了我的代碼，這樣這個類就可以簡單地使用 print() 或我喜歡的任何其他顯示方法.然而，Kivy 似乎并不喜歡這種方法.我為我的視圖擴展了 Kivy 的 BoxLayout 類，并且可以調用 message() 函數.這個類看起來像這樣:
I have a socket client that calls a View() class every time it receives a message. I've split my code in such a way such that this class can simply use print() or any other display method, as I like. However, it seems that Kivy is not fond of this method. I've extended Kivy's BoxLayout class for my view and can call the message() function. The class looks something like this:
class View(BoxLayout):
def __init__(self, **kwargs):
super(View, self).__init__(**kwargs)
self.btn = Button(text='Default')
# Bind button press method
self.btn.bind(on_press=self.message)
self.add_widget(self.btn)
def message(self, message):
self.btn.text = 'Meow'
self.add_widget(Button(text='Meow'))
print(str(message))
message 函數確實被調用并打印但界面沒有更新.但是，當我按下按鈕時，它會更新界面和打印.
The message function is indeed called and it prints but the interface does not update. When I press the button however, it does update the interface as well as print.
我研究過使用 StringProperty 來修改按鈕文本，但也失敗了.順便說一句，如果我正在做的事情完全不可行，我會嘗試稍后以板的形式繪制一個由 width * height 按鈕組成的整個界面.
I've looked into using a StringProperty to modify the button text but have failed that too. Just as a note, in case what I'm doing is completely infeasible, I'm trying to later draw an entire interface consisting of width * height buttons, in the form of a board.
非常感謝任何意見，這讓我發瘋了.
Any input is very much appreciated, it's been driving me insane.
編輯 1*我關注了一些評論并嘗試了一些事情.我添加了一個
Clock 類并讓它從 View 安排一個 update() 方法.update 方法只是改變一些元素的文本.當我安排它時，我注意到它可以工作，如下所示:
EDIT 1* I've followed on a few comments and tried a few things out. I've added a
Clock class and have it schedule an update() method from View. The update method simply changes the text of a few elements. I've noticed it works when I schedule it to, as shown below:
def update(self, *args, **kwargs):
self.btn.text = ''.join(random.choice(string.ascii_uppercase + string.ascii_lowercase) for i in range(32))
def message(self, message):
try:
print(message)
self.text = 'sending'
except Exception as e:
print(e)
線程現在只分配文本屬性，如 message() 所示.周期性觸發的 update() 方法也可以工作，分配隨機文本.但是現在的問題是它無法設置文本.這不起作用:
The thread now simply assigns the text property as seen in message(). The periodically triggered update() methods works too, assigning random text. Now the issue however that it cannot set the text. This does not work:
def update(self, *args, **kwargs):
self.btn.text = self.text
我肯定在其他地方做錯了，有什么建議嗎?
I must be doing wrong elsewhere, any suggestions?
編輯 2*我要調試的錯誤是 here.
推薦答案
由于您沒有發布完整的工作示例，我只能猜測您在做什么.似乎您在線程上有一個事件(傳入消息)，并且您希望在發生這種情況時顯示一些文本.您需要將 UI 更新推送"到主線程，但您不需要使用 Clock 進行 周期性 更新，您可以使用 Clock.schedule_once.
Since you don't post a full working example, I can only guess at what your doing. It seems you have an event (incoming message) on a thread, and you want to display some text when this occurs. You need to 'push' UI updates to the main thread, but you don't need to do periodic updates with Clock, you can just schedule one-time calls with Clock.schedule_once.
from functools import partial
def update(self, text, *a):
self.btn.text = text
def message(self, message):
Clock.schedule_once(partial(self.update, message), 0)
如上所述，您可以使用 @mainthread 裝飾器:
As inclement mentioned, you can do this 'push to main thread' automatically with the @mainthread decorator:
@mainthread
def update(self, text):
self.btn.text = text
def message(self, message):
update(message)
這樣，每當你調用 update 時，它都會在主線程上執行.
This way, whenever you call update it will be executed on the main thread.
這篇關于如何從線程更新 Kivy 元素?的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！