控制#
介绍#
控件包括用于计时、程序流程、条件逻辑和项目终止的方法。这些控件允许您暂停执行、创建循环、定义逻辑路径以及结束程序。以下是可用控件的列表,包括方法和核心 Python 关键字:
wait
– Pauses execution for a given number of milliseconds or seconds.for
– Repeats code for each item in a sequence.if
– Executes code if a condition is true.if/else
– Runs different code depending on a condition.if/elif/else
– Checks multiple conditions in order.while
– Repeats code while a condition is true.break
– Exits a loop immediately.quit
– Ends the running project.pass
– Placeholder used when no action is needed.
wait#
wait
pauses for a specific amount of time before moving to the next method.
Usage:
wait(time, units)
参数 |
描述 |
---|---|
|
等待的时间量,以正整数表示。 |
|
The unit to represent the time:
|
# Fly for 1 second.
drone.take_off(climb_to=500)
wait(1, SECONDS)
drone.land()
for#
for
iterates over a sequence (such as a list, tuple, dictionary, set, or string) or any iterable object. It executes the block of code once for each item in the sequence.
使用量:
for value in expression_list:
pass
参数 |
描述 |
---|---|
|
存储迭代中的当前元素的临时变量。 |
|
循环遍历的元素集合(例如,列表、字符串、范围)。 |
# Move back and forth four times then land.
drone.take_off(climb_to=500)
for i in range(4):
drone.move_for(direction=0, distance=500, velocity=50, units=MM)
wait(1, SECONDS)
drone.move_for(direction=180, distance=500, velocity=50, units=MM)
wait(1, SECONDS)
drone.land()
# Print each item in a list.
colors = ["Red", "Green", "Blue"]
for color in colors:
controller.screen.print(color)
controller.screen.next_row()
if#
if
executes the indented block of code if the condition evaluates as True
.
用法:
if condition:
pass
参数 |
描述 |
---|---|
|
An expression or variable that is evaluated when the statement runs. If it evaluates as |
# Take a picture when button 5 is pressed.
drone.take_off(climb_to=500)
while True:
# Move with controller
drone.move_with_vectors(
forward=controller.axis4.position(),
rightward=controller.axis3.position(),
upward=controller.axis1.position(),
rotation=controller.axis2.position()
)
if controller.button5.pressing():
drone.camera.capture_image(FORWARD_CAMERA)
wait(5, MSEC)
if/else#
if
and else
determine which indented block of code runs based on whether the condition evaluates as True
or False
.
用法:
if condition:
pass
else:
pass
参数 |
描述 |
---|---|
|
An expression or variable that is evaluated when the statement runs. If it evaluates as |
# Climb when the left joystick is moved up.
drone.take_off(climb_to=500)
while True:
if controller.axis1.position() > 0:
drone.climb(direction=UP, velocity=50)
else:
drone.hover()
wait(5, MSEC)
if/elif/else#
The if/elif/else
structure selects which indented block of code runs based on conditions:
if
runs its block if the condition evaluates asTrue
.elif
checks additional conditions only if all previous conditions evaluated asFalse
. Multipleelif
statements can be used.else
runs its block only if none of the previous conditions evaluated asTrue
.
用法:
if condition:
pass
elif condition:
pass
else:
pass
参数 |
描述 |
---|---|
|
An expression or variable that is evaluated when the statement runs. The first condition that evaluates as |
# Move the drone up or down based on the position of the joystick.
drone.take_off(climb_to=500)
while True:
position = controller.axis1.position()
if position > 0:
drone.climb(direction=UP, velocity=50)
elif position < 0:
drone.climb(direction=DOWN, velocity=50)
else:
drone.hover()
wait(5, MSEC)
while#
while
repeatedly runs methods as long as the condition is True
. It can also be used like a “Wait until” by adding not
to the condition, as shown in the example below.
用法:
while condition:
pass
参数 |
描述 |
---|---|
|
An expression or variable that is evaluated before each iteration. If it evaluates as |
# Hover at 200 mm.
drone.take_off(climb_to=500)
while drone.range.get_distance(DOWNWARD_RANGE, MM) > 200:
drone.climb(direction=DOWN, velocity=10)
drone.hover()
wait(3, SECONDS)
drone.land()
break#
break
exits a loop immediately.
# Land when button 5 is pressed.
drone.take_off(climb_to=500)
while True:
# Move with controller
drone.move_with_vectors(
forward=controller.axis4.position(),
rightward=controller.axis3.position(),
upward=controller.axis1.position(),
rotation=controller.axis2.position()
)
if controller.button5.pressing():
break
wait(5, MSEC)
drone.land()
quit#
quit
ends a running project.
Usage:
quit()
参数 |
描述 |
---|---|
该方法没有参数。 |
# Land when button 5 is pressed.
drone.take_off(climb_to=500)
while True:
# Move with controller
drone.move_with_vectors(
forward=controller.axis4.position(),
rightward=controller.axis3.position(),
upward=controller.axis1.position(),
rotation=controller.axis2.position()
)
if controller.button5.pressing():
quit()
wait(5, MSEC)
drone.land()
pass#
pass
is a placeholder for future code and can be used to avoid errors in empty loops, conditionals, and functions.
if condition:
pass
def function():
pass