如何使用Zelle的graphics.py更改帧但仍然使用相同的窗口？

Question

Im SO SO SO stuck on this AND becoming really desperate now.. WE have to create a mini program using the graphics.py library. So basically what i want to know is how can I have like a start menu and then when the user clicks.. it changes to a different frame of the 'game' essentially??

My friend suggested using the .undraw() function but i dont think that works for text & also just changing the .setText("") to an empty string as im trying to get rid of the title & subheading... This is my code:

from graphics import *
# create the window to hold the contents
win = GraphWin("SHAPES FRENZY", 800, 500)
win.setBackground("Black")
#Setting the Title Page:
title=Text(Point(400,250),"Shapes Frenzy.")
title.draw(win)
#Subheading
subheading=Text(Point(400,290), "Click anywhere to continue.")
subheading.draw(win)

#Next Frame
clickPoint = win.getMouse()
if clickPoint == True:
    title.undraw() #THIS DOESNT WORK.
    subheading.undraw()

#Setting up Second frame of program.
hi=Text(Point(500,250),"Please Work.")
hi.setFace('courier')
hi.draw(win)

win.getMouse() # Pause to view result
win.close()    # Close window when done

Answer 1

don't worry - breath :)

win.getMouse() isn't working as you think it is. what you want is really like this:

clickPoint = win.getMouse()
title.setText("")  #THIS DOESNT WORK.
subheading.setText("")

win.getMouse() will return a Point object. Here is a stripped definition from the library:

def getMouse(self):
    """Wait for mouse click and return Point object representing
    the click"""
    # gets some stuff ready
    while self.mouseX == None or self.mouseY == None:
        # waits for click
    # post click code
    return Point(x,y)

The doc string really says it all.. but essentially win.getMouse() is going to block your program because it is going to be running inside that while loop until a click is registered. Finally, notice that Point(x,y) is returned.

What was going wrong was...

You were assigning the output win.getMouse() of win.getMouse to a variable. This variable's value would look something like this: Point(161.0, 247.0) . so when it hit your if expression. Python was checking that Point(161.0, 247.0) == True . Well, obviously it doesn't! so, what was happening is you're if block was never getting executed, and the setText you tried was never run in the first place.

For future debugging, try adding print statement to ensure code is executed when you think it is :). Eg

print("this will definitely print")
if clickPoint == True:
    print("Code is being run!")
    title.undraw() #THIS DOESNT WORK.
    subheading.undraw()

And you'll notice that in the output of your program, the second print statement never occurred.

Also, if you open up the graphics library (it is pretty small so not too big of a deal) and take a look at the Text object you'll see that there is no undraw method defined for the Text class. there is a setText method available, so I went ahead an used that method and set the text to an empty string.

Ah, last thing. Since your goal of the if statement was to just hold your program until the user clicked anywhere, and the getMouse method did that anyways (stuck in while loop until a click occurs), the correct thing to do is to just drop the if statement entirely.

Good luck!