python-默认文本以及列表textvariable Entry小部件Tkinter

我有以下输入框,由于获取值,我在其中输入了textvariable的列表选项.

但是我想知道是否可以在背景中放置默认文本,以显示每个框中需要的值(例如灰度文本,“值1”,“值2”等.).

self.numbers = [StringVar() for i in xrange(self.number_boxes) ] #Name available in global scope.       
box=Entry(self.frame_table,bg='white',borderwidth=0, width=10, justify="center", textvariable=self.numbers[i])

我是否可以在框内单击鼠标后添加一些更改“文本变量”的内容,还是可以仅添加另一个文本变量或文本来设置默认文本？

  self.box = []

  for i in xrange(self.number_boxes):

        self.clicked = False
        self.box.append(Entry(self.frame_table,bg='white',borderwidth=0, width=10, justify="center", textvariable=self.numbers[i], fg='grey'))
        self.box[i].grid(row=row_list,column=column+i, sticky='nsew', padx=1, pady=1) 
        self.box[i].insert(0, "Value %g" % float(i+1))
        self.box[i].bind("<Button-1>", self.callback)

解决方法:

为了将默认文本放在Entry小部件中,可以使用here所述的insert()方法.

box.insert(0, "Value 1")    # Set default text at cursor position 0.

现在,为了在用户在框内单击鼠标后更改框的内容,您需要将事件绑定到Entry对象.例如,以下代码在单击该框时将其删除. (您可以阅读有关事件和绑定here的信息.)在下面,我显示了一个完整的示例.

请注意,删除框中的文本可能仅对第一次单击有效(即删除默认内容时),因此我创建了一个单击的全局标志以跟踪是否已单击它.

from tkinter import Tk, Entry, END    # Python3. For Python2.x, import Tkinter.

# Use this as a flag to indicate if the box was clicked.
global clicked   
clicked = False

# Delete the contents of the Entry widget. Use the flag
# so that this only happens the first time.
def callback(event):
    global clicked
    if (clicked == False):
        box[0].delete(0, END)         #  
        box[0].config(fg = "black")   # Change the colour of the text here.
        clicked = True

root = Tk()
box = []                              # Declare a list for the Entry widgets.

box.append(Entry(fg = "gray"))        # Create an Entry box with gray text.
box[0].bind("<Button-1>", callback)   # Bind a mouse-click to the callback function.
box[0].insert(0, "Value 1")           # Set default text at cursor position 0.

box.append(Entry(fg = "gray"))        # Make a 2nd Entry; store a reference to it in box.
box[1].insert(0, "Value 2")

box[0].pack()                         #
box[1].pack()

if __name__ == "__main__":
    root.mainloop()

标签：list,tkinter,ttk,python,user-interface
来源： https://codeday.me/bug/20191101/1981309.html