我正在研究一些代码来移动画布上绘制的形状。它总体上是一个矢量绘图程序,所以我需要能够移动一个形状,然后移动另一个形状。
到目前为止,我的代码适用于移动一个形状,但是当我然后尝试移动屏幕上的另一个形状时,形状会在我点击它之前跳转。我认为发生的事情是移动形状的代码没有点击就被激活了,因此代码中的坐标没有被重置,导致形状跳跃(我的代码应该得到第二个的坐标)点击时的形状,我希望)
我尝试在网上寻找没有点击工作但没有找到任何东西的任何理由。我还尝试解开放置第一个形状后移动形状的标签,这样在单击第二个形状之前它们就不会被绑定,但这似乎不起作用。
有谁能解释这里发生了什么?
#code for a two shapes
circle = Main_Window.create_image(500,400, image = CircleIm, tags = "circle")
shape = circle
type1 = Move_Shape(shape)
Main_Window.tag_bind(circle, "<ButtonPress-3>", type1.moveShape(shape))
triangle= Main_Window.create_image(500,400, image = TriangleIm, tags = "triangle")
shape = triangle
type1 = Move_Shape(shape)
Main_Window.tag_bind(triangle, "<ButtonPress-3>", type1.moveShape(shape))
class Move_Shape:
def __init__(self, shape):
self.shape = shape
return
def getShapeType(self, shape):
global shapeType
print(self.shape)
shapeType = Main_Window.gettags(self.shape)
return shapeType
def moveShape(self, shape):
#while left button is held down, we want it to move the tagged shape to move to the position of the mouse
global b1, currentX, currentY
b1 = "down"
newX, newY = None, None
shapeType = self.getShapeType(shape)
print(shapeType)
Main_Window.addtag_withtag("move_shape", shapeType[0])
#Bind move_shape to moving code
print("new tags are", Main_Window.gettags(self.shape))
Main_Window.tag_bind("move_shape","<Motion>", self.whileMoving)
Main_Window.tag_bind("move_shape","<ButtonPress-3>", self.getCurrentCoords)
Main_Window.tag_bind("move_shape", "<ButtonPress-1>", self.startMoving)
Main_Window.tag_bind("move_shape", "<ButtonRelease-1>", self.stopMoving)
root_window.mainloop()
return shape
def getCurrentCoords(self, event):
global currentX, currentY
#make sure the coordinates are obtained before user tries to move shape
coords = Main_Window.coords(shapeType[0])
currentX= coords[0]
currentY = coords[1]
return currentX, currentY
def startMoving(self,event):
global b1
b1 = "down"
return
def stopMoving(self, event):
global b1
b1 = "up"
newX = None
newY = None
return b1, newX, newY
def whileMoving(self, event):
global shapeType, b1, currentX, currentY
if b1 == "down":
newX = event.x
newY = event.y
if newX is not None and newY is not None:
x = newX - currentX
y = newY - currentY
Main_Window.move(shapeType[0],x,y)
currentX = newX
currentY = newY
newX = event.x
newY= event.y
return
答案 0 :(得分:0)
要使用参数绑定函数,请使用lambda
关键字:
Main_Window.tag_bind(triangle, "<ButtonPress-3>", lambda shape: type1.moveShape(shape))
如果执行Main_Window.tag_bind(triangle, "<ButtonPress-3>", type1.moveShape(shape))
,Python将在创建窗口小部件之前调用回调函数,并将函数的返回值传递给Tkinter。然后Tkinter尝试将返回值转换为字符串,并告诉Tk在激活按钮时调用具有该名称的函数。这可能不是你想要的。
对于像这样的简单情况,你可以使用lambda表达式作为Tkinter和回调函数之间的链接(我对effbot.org进行了解释)