1

我在 tkinter 中有一个自定义圆形按钮

这是代码：

class RoundedButton(tk.Canvas):
    def __init__(self, parent, bg, width,  height = None,  command=None, color = "red", padding = 0, cornerradius = None):
        height = width if height == None else height
        cornerradius = min(width, height) / 2 if cornerradius == None else cornerradius

        tk.Canvas.__init__(self, parent, borderwidth=0, 
            relief="flat", highlightthickness=0, bg=bg)
        self.command = command

        if cornerradius > 0.5*width:
            print("Error: cornerradius is greater than width.")
            return None

        if cornerradius > 0.5*height:
            print("Error: cornerradius is greater than height.")
            return None

        rad = 2*cornerradius
        def shape():
            self.create_polygon((padding,height-cornerradius-padding,padding,cornerradius+padding,padding+cornerradius,padding,width-padding-cornerradius,padding,width-padding,cornerradius+padding,width-padding,height-cornerradius-padding,width-padding-cornerradius,height-padding,padding+cornerradius,height-padding), fill=color, outline=color)
            self.create_arc((padding,padding+rad,padding+rad,padding), start=90, extent=90, fill=color, outline=color)
            self.create_arc((width-padding-rad,padding,width-padding,padding+rad), start=0, extent=90, fill=color, outline=color)
            self.create_arc((width-padding,height-rad-padding,width-padding-rad,height-padding), start=270, extent=90, fill=color, outline=color)
            self.create_arc((padding,height-padding-rad,padding+rad,height-padding), start=180, extent=90, fill=color, outline=color)

        id = shape()
        (x0,y0,x1,y1)  = self.bbox("all")
        width = (x1-x0)
        height = (y1-y0)
        self.configure(width=width, height=height)
        self.bind("<ButtonPress-1>", self._on_press)
        self.bind("<ButtonRelease-1>", self._on_release)

    def _on_press(self, event):
        # print(event)
        self.configure(relief="sunken")

    def _on_release(self, event):
        # print(event)
        self.configure(relief="raised")
        if self.command is not None:
            self.command()

此代码有效，但没有向其添加文本的功能。我认为要向这个圆形按钮添加文本，我需要在类中创建另一个函数，该函数将采用 x 和 y 坐标并将其放置在它的父级中，但是在放置时我们需要创建一些标签或一些文本根据 x 和 y 坐标放置。但是，我不知道如何计算应该放置的文本的位置。有人可以帮我吗？我确信必须进行一些计算才能找到文本的位置。

4

2 回答 2

2

您只需使用以下命令将文本放在画布的中心.create_text(...)：

def __init__(self, parent, bg, width, height=None, text="", font=None, command=None, color="red", padding=0, cornerradius=None):
    ...
    height = (x1-x0)
    width = (y1-y0)
    # show the text at the center of canvas
    self.create_text(width/2, height/2, text=text, font=font)
    ...
于 2021-01-21T04:10:27.130 回答
2

虽然@acw1668 可以工作，但我建议您将configure事件绑定到事件处理程序并重新调整位置。这样，文字会一直居中

class RoundedButton(tk.Canvas):
    def __init__(self, parent, bg, text='Hello', width=10,  height = 10,  command=None, color = "red", padding = 0, cornerradius = 4):
        super().__init__(parent)
    
        ....
        self.btn_text = self.create_text(0, 0, text=text)
        self.bind('<Configure>', self.readjust) 
        ....
    
    def readjust(self, event):
        self.coords(self.btn_text, event.width/2, event.height/2)
于 2021-01-21T04:23:18.973 回答