Tkinter程序文本无法显示：自定义模块及直接调用均无效求助

问题描述 #

开发的Tkinter程序无法显示文本，调用自定义terkinter模块的addText方法无效，直接调用canvas的create_text方法也看不到文本。

主程序代码 #

import tkinter as tk
import terkinter as tr
import os
import re

win = tk.Tk()
allowedChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz_"
win.title("Terminos")
canv = tr.Trk(win,15,30)
canv.addText(6,6,"hello world!")
canv.canvas.create_text(canv.screenwidth-5,canv.screenheight-5,text=f"hello world!")
win.geometry(f'{canv.screenwidth}x{canv.screenheight}')

win.mainloop()

自定义terkinter模块代码 #

import tkinter as tk

class Trk:
    """
    The class of creating
    a canvas, and
    easily manipulating it
    with the TUI functions.
    """
    global screenWidth, screenHeight
    def __init__(self,win,blocksx,blocksy,bg="#232627"):
        self.screenwidth = win.winfo_screenwidth()
        self.screenheight = win.winfo_screenheight()
        self.canvas = tk.Canvas(win,width=self.screenwidth,height=self.screenheight,background=bg)
        self.canvas.pack()
        self.background = bg
        self.parent = win
        self.winwidth = win.winfo_width()
        self.winheight = win.winfo_height()
        self.width = self.canvas.winfo_width()
        self.height = self.canvas.winfo_height()
        self.blockx = blocksx
        self.blocky = blocksy
        self.blocks = self.blockList()
    def coordinate(self,row,col):
         return row*self.blockx, (self.winheight-col)*self.blocky
    def blockList(self):
        li = []
        for i in range(self.blockx):
            tmp = []
            for j in range(self.blocky):
                 tmp.append(None)
            li.append(tmp)
        return li
    def addText(self,row,col,text,font="1:1",color="white"):
        row, col = self.coordinate(row,col)
        self.canvas.create_text(row,col,text=text,fill=color)
    def kill(self):
        self.canvas.destroy()

问题原因分析 #

1. 窗口尺寸初始化时机错误：创建Trk实例后才设置win.geometry，导致__init__中调用win.winfo_width()和win.winfo_height()获取的是窗口默认最小尺寸（通常为1x1），后续coordinate方法计算出的坐标完全不符合预期。
2. 文本坐标超出可见区域：直接调用create_text时使用canv.screenwidth-5和canv.screenheight-5作为坐标，窗口标题栏会占用部分高度，导致文本被窗口底部边框遮挡，无法显示。
3. 坐标计算逻辑错误：coordinate方法中(self.winheight-col)*self.blocky的计算方式，在winheight极小的情况下会得到负数或超出canvas范围的坐标，文本被绘制到不可见区域。

修复方案 #

1. 调整窗口尺寸设置时机 #

先设置窗口尺寸，再创建Trk实例，确保初始化时能获取正确的窗口大小。

2. 修正坐标计算逻辑 #

调整coordinate方法的计算方式，基于canvas的实际尺寸而非窗口初始尺寸，同时避免负数坐标。

3. 调整直接绘制文本的坐标 #

预留足够的边距，避免文本被窗口边框遮挡。

修复后的代码 #

主程序代码 #

import tkinter as tk
import terkinter as tr
import os
import re

win = tk.Tk()
allowedChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz_"
win.title("Terminos")
# 先设置窗口尺寸
screen_width = win.winfo_screenwidth()
screen_height = win.winfo_screenheight()
win.geometry(f'{screen_width}x{screen_height}')
# 强制更新窗口，确保获取正确的尺寸
win.update_idletasks()
# 再创建Trk实例
canv = tr.Trk(win,15,30)
canv.addText(6,6,"hello world!")
# 调整坐标，预留边距
canv.canvas.create_text(screen_width-20, screen_height-40, text=f"hello world!", fill="white")

win.mainloop()

自定义terkinter模块代码 #

import tkinter as tk

class Trk:
    """
    创建画布并通过TUI函数轻松操作的类
    """
    def __init__(self,win,blocksx,blocksy,bg="#232627"):
        self.screenwidth = win.winfo_screenwidth()
        self.screenheight = win.winfo_screenheight()
        self.canvas = tk.Canvas(win,width=self.screenwidth,height=self.screenheight,background=bg)
        self.canvas.pack(fill=tk.BOTH, expand=True)  # 让画布填充整个窗口
        self.background = bg
        self.parent = win
        # 强制更新后获取正确的窗口和画布尺寸
        win.update_idletasks()
        self.winwidth = win.winfo_width()
        self.winheight = win.winfo_height()
        self.width = self.canvas.winfo_width()
        self.height = self.canvas.winfo_height()
        self.blockx = blocksx
        self.blocky = blocksy
        self.blocks = self.blockList()
    
    def coordinate(self,row,col):
        # 修正坐标计算，确保在画布可见范围内，避免负数
        x = row * self.blockx
        # 从画布顶部开始计算y坐标，而非窗口高度减col
        y = col * self.blocky
        # 确保坐标不超出画布范围
        x = max(0, min(x, self.width))
        y = max(0, min(y, self.height))
        return x, y
    
    def blockList(self):
        li = []
        for i in range(self.blockx):
            tmp = []
            for j in range(self.blocky):
                 tmp.append(None)
            li.append(tmp)
        return li
    
    def addText(self,row,col,text,font=("Arial",12),color="white"):
        row, col = self.coordinate(row,col)
        self.canvas.create_text(row,col,text=text,fill=color, font=font)
    
    def kill(self):
        self.canvas.destroy()

内容的提问来源于stack exchange，提问作者Felix508