Guizero文本框焦点

Question

我是一个新手，我有一个小脚本，使用guizero创建一个小应用程序，读取rfid标签并激活门锁。我遇到的问题是，当电源关闭，树莓派重新启动。脚本启动，但我必须手动单击文本框之前，它将开始工作。如何让它在启动时自动将焦点设置在文本框上?谢谢马克。

下面是代码，我在网上找到了这个项目，并修改了一些为我工作。

from gpiozero import LED, Buzzer
from guizero import App, Box, Text, TextBox, warn
import gpiozero
import csv
RELAY_PIN = 17
led8 = LED(5)
led9 = LED(6)
relay= gpiozero.OutputDevice(RELAY_PIN,active_high=False, initial_value=False)

def clearDisplay():
print("Clear display")
rfidStatus.value = "—"
rfidText.value = ""
led8.off()
led9.off()
relay.off()
rfidStatus.repeat(1000, checkRFidTag)


def checkRFidTag():
tagId = rfidText.value
if tagId != "":
RFidRegistered = False
print(tagId)
with open("Database.csv") as csvfile:
reader = csv.DictReader(csvfile)
for row in reader:
if row["RFid"] == tagId:
RFidRegistered = True
print("Welcome " + row["User"])
rfidStatus.value = "Welcome " + row["User"]
led8.on()
relay.toggle()                 
rfidStatus.after(5000, clearDisplay)


if RFidRegistered == False:
print("RFid tag is not registered")
rfidStatus.value = "RFid tag is not registered"
led9.on()
rfidStatus.after(3000, clearDisplay)

rfidStatus.cancel(checkRFidTag)

app = App(title="RFID EM4100 Simple GUI", width=350, height=150, layout="auto")

instructionText = Text(app, text="Click on the text button belownand scan your RFid tag.")
rfidText = TextBox(app,text="")
rfidStatus = Text(app, text="—")
rfidStatus.repeat(1000, checkRFidTag)
#designBy = Text(app, text="Design by Idris – Cytron Technologies", align="bottom")

app.display()
view

Answer 1

你可以使用与应用程序相关联的计时器在启动后不久调用一个函数。例如，使用:

app.after(1000,setFocus)

调用:

def setFocus():
nameOfTextBox.focus()

下面的示例设置了两个文本框和两个按钮。通过注释掉setFocus中的一行或其他行，它在一秒钟后将焦点设置为右侧文本框或取消按钮:

from guizero import App, Text, Box, TextBox, PushButton
import sys
app = App(title="Give Focus")
app.width = 500
app.height = 100
paddingHeight = 1
paddingWidth = 10
buttonWidth = 10
topBoxHeight = 100
bottomBoxHeight = 100
app.height = topBoxHeight + bottomBoxHeight
def setFocus():
rightTextBox.focus()
#    buttonCancel.focus()

def call_exit():
buttonCancel.text="Exiting"
buttonCancel.enabled=False
app.update()
app.destroy()
sys.exit()


topBox = Box(app, align="top", width= "fill", height = topBoxHeight, border= True)
textFieldBox = Box(topBox, align="top", width= "fill", height= "fill", border= True, layout = "grid")
paddingT00 = Text(textFieldBox, text="", width = paddingWidth, height = paddingHeight, grid = [0,0])
paddingT10 = Text(textFieldBox, text="", width = paddingWidth, height = paddingHeight, grid = [1,0])
message = Text(textFieldBox, text="Text Field Box", grid = [2,0])
paddingT01 = Text(textFieldBox, text="", width = paddingWidth, height = paddingHeight, grid = [0,1])
leftTextBox = TextBox(textFieldBox, text="Type here", width = paddingWidth, height = 1, grid = [1,1])
paddingT21 = Text(textFieldBox, text="", width = paddingWidth, height = paddingHeight, grid = [2,1])
rightTextBox = TextBox(textFieldBox, text="...or here", width = paddingWidth, height = 1, grid = [3,1])

bottomBox = Box(app, align="top", width= "fill", height = bottomBoxHeight, border= True)
buttonBox = Box(bottomBox, align="top", width= "fill", height= "fill", border= True, layout = "grid")
paddingB00 = Text(buttonBox, text="", width = paddingWidth, height = paddingHeight, grid = [0,0])
paddingB10 = Text(buttonBox, text="", width = paddingWidth, height = paddingHeight, grid = [1,0])
message = Text(buttonBox, text="Button Box", grid = [2,0])
paddingB01 = Text(buttonBox, text="", width = paddingWidth, height = paddingHeight, grid = [0,1])
buttonOK = PushButton(buttonBox, text="OK", width = paddingWidth, height = 1, grid = [1,1])
paddingB21 = Text(buttonBox, text="", width = paddingWidth, height = paddingHeight, grid = [2,1])
buttonCancel = PushButton(buttonBox, text="Cancel", command = call_exit, width = paddingWidth, height = 1, grid = [3,1])
app.after(1000,setFocus)
app.display()