在完成按钮调用的函数执行之前让 Kivy 更新 PopUp

Question

关于问题： 在 sutPopUp.create() 中，我试图让弹出窗口自行更新（删除它的两个按钮并更改“隐藏”标签） .我已经尝试过线程更新函数和调用 Clock.schedule_once(self.update_txt, -1)，但都没有工作。他们似乎都在等待 run_local_command，这只是一个运行本地命令的阻塞函数。下面是python代码：

class sutPopUp(Popup):
    pop_float = ObjectProperty(None)
    sutPopUp_create = ObjectProperty(None)
    sutPopUp_cancel = ObjectProperty(None)
    sut_wait_text = ObjectProperty(None)
    sutPopUp_input = ObjectProperty(None)

    def __init__(self, my_widget,**kwargs):
        super(sutPopUp,self).__init__(**kwargs)
        self.title = "Test Station Setup"
        self.size_hint = (None, None)
        self.size = (400, 200)

    def create(self, *args):
        self.quick_change_thread = threading.Thread(target=self.update_txt)
        self.quick_change_thread.start()
        time.sleep(1)

        sut_name = self.sutPopUp_input.text
        create_cmd = "python project.py -c " + sut_name
        create_handle = run_local_command(create_cmd, True, "C:\Project")

        wm.current = "blank"
        wm.remove_widget(screens[2])
        screens[2] = Dashboard(name="dashboard_screen")
        wm.add_widget(screens[2])
        wm.current = "dashboard_screen"

        self.dismiss()
        self.quick_change_thread.join()

    def update_txt(self):
        self.sutPopUp_create.disabled = True
        self.sutPopUp_cancel.disabled = True
        self.pop_float.remove_widget(self.sutPopUp_create)
        self.pop_float.remove_widget(self.sutPopUp_cancel)
        self.sut_wait_text.text = "Creating Test Station ..."

这是kv：

<sutPopUp@Popup>
    pop_float:pop_float
    sutPopUp_create:sutPopUp_create
    sutPopUp_cancel:sutPopUp_cancel
    sut_wait_text:sut_wait_text
    sutPopUp_input:sutPopUp_input

    FloatLayout:
        id: pop_float
        size: root.height, root.width
        Label:
            text: "Enter Test Station Name:"
            pos_hint:{"x":0.1,"top":0.9}
            size_hint: 0.25, 0.2
        TextInput:
            id: sutPopUp_input
            multiline: False
            pos_hint:{"x":0,"top":0.7}
            size_hint: 1, 0.2
        Label:
            id: sut_wait_text
            text: ""
            pos_hint:{"x":0.4,"top":0.3}
            size_hint: 0.25, 0.2
        Button:
            id: sutPopUp_create
            text: "Create"
            pos_hint:{"x":0.1,"top":0.3}
            size_hint: 0.3, 0.2
            on_release: root.create()

        Button:
            id: sutPopUp_cancel
            text: "Cancel"
            pos_hint:{"x":0.6,"top":0.3}
            size_hint: 0.3, 0.2
            on_release: root.dismiss()

Answer 1

我建议将create() 方法分成三个方法。由于create()方法是由Button按下发起的，它会运行在主线程上，所以直接调用update_text()方法即可。然后使用另一个线程运行create_cmd。然后，该新线程使用Clock.schedule_once() 将原始create() 方法（新的finish_create() 方法）的剩余代码运行回主线程。

def create(self, *args):
    self.update_text()  # this needs to run on the main thread
    # time.sleep(1)  # ??? this will freeze your app for 1 second

    Thread(target=self.do_create).start()

def do_create(self):
    sut_name = self.sutPopUp_input.text
    create_cmd = "python project.py -c " + sut_name
    create_handle = run_local_command(create_cmd, True, "C:\Project")

    # after above command completes, run the rest of the former create() back on the main thread
    Clock.schedule_once(self.finish_create)

def finish_create(self, dt):
    wm.current = "blank"
    wm.remove_widget(screens[2])
    screens[2] = Dashboard(name="dashboard_screen")
    wm.add_widget(screens[2])
    wm.current = "dashboard_screen"

    self.dismiss()

无论你做什么，当有一个函数保持主线程时，GUI 中的任何内容都不会更新。所以这种方法最大限度地减少了花在主线程上的时间。此代码未经测试，因此可能存在错误。但我相信这种方法应该可以实现您想要的。