我正在创建一个带有tkinter的程序,它带有一个存储在文本文件中的默认名称和密码。登录后,您需要打开 public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// Setup the new range seek bar
RangeSeekBar<Integer> rangeSeekBar = new RangeSeekBar<>(this);
// Set the range
rangeSeekBar.setRangeValues(15, 90);
rangeSeekBar.setSelectedMinValue(20);
rangeSeekBar.setSelectedMaxValue(88);
// Add to layout
FrameLayout layout = (FrameLayout) findViewById(R.id.seekbar_placeholder);
layout.addView(rangeSeekBar);
// Seek bar for which we will set text color in code
RangeSeekBar rangeSeekBarTextColorWithCode = (RangeSeekBar) findViewById(R.id.rangeSeekBarTextColorWithCode);
rangeSeekBarTextColorWithCode.setTextAboveThumbsColorResource(android.R.color.holo_blue_bright);
rangeSeekBar.setOnRangeSeekBarChangeListener(new RangeSeekBar.OnRangeSeekBarChangeListener<Integer>() {
@Override
public void onRangeSeekBarValuesChanged(RangeSeekBar<Integer> bar, Integer minValue, Integer maxValue) {
int hours = minValue / 4; // it will return hours.
int minutes = (minValue % 4) * 15;
Toast.makeText(getApplicationContext(), hours + " Hours - " + hours + ":" + minutes, Toast.LENGTH_SHORT).show();
}
});
}
窗口并输入要在后续登录中使用的名称和密码。我已经定义了我的变量,但如果我想覆盖文本文件,我会收到以下内容:
错误“NameError:名称'e1'未定义”
我知道我已定义。
Toplevel
答案 0 :(得分:0)
所以你有几个选择,但一般来说你有两个主要问题。
第一个问题是在创建.pack()
和e1
条目字段后使用e2
。这是get()
方法的问题,因为如果以这种方式打包,几何管理器将返回None
。正确的方法是首先使用e1 = Entry(ch, width=20)
创建窗口小部件,然后使用e1.pack()
将其打包到下一行,这样get()
就可以使用e1
。
第二个问题是局部变量与全局变量的关系。您已在函数e1
内创建了e2
和change_login()
,并且没有告诉python e1
和e2
是全局变量,它会自动假设您希望它们为局部变量。这意味着只能从创建它们的函数中访问变量。
你有几个选择我会为你解决。
1)快速和脏选项是将e1
和e2
指定为全局变量。这可以通过global var_name, var2_name, and_so_on
来完成,因此在这种情况下,请将此行添加到change_login():
和save_changes()
函数的顶部:
global e1, e2
这告诉python将e1
和e2
添加到全局名称空间,它将允许save_changes()
使用全局名称空间中的变量。
2)另一种方法是使用button命令将2个变量传递给save_changes()
。我们需要使用lambda
来实现这一点,我们可以通过添加:
command = lambda e1=e1, e2=e2: save_changes(e1, e2)
在change_login()
中创建的按钮,并将{2}参数添加到save_changes()
,如下所示:
save_changes(e1, e2)
这与第一个选项一样有效,也避免使用全局变量。
3)第三种选择是将整个程序创建为类,并使用类属性允许变量与类中的所有方法一起使用。
以下是使用第一个选项的代码示例:
import sys
from tkinter import messagebox
from tkinter import *
now = open("pass.txt","w+")
now.write("user\n")
now.write("python3")
now.close()
def login_in():
with open("pass.txt") as f:
new = f.readlines()
name = new[0].rstrip()
password = new[1].rstrip()
if entry1.get() == name and entry2.get() == password:
root.deiconify()
log.destroy()
else:
messagebox.showerror("error","login Failed")
def change_login():
global e1, e2
ch = Toplevel(root)
ch.geometry('300x300')
e1 = Entry(ch, width=20)
e1.pack()
e2 = Entry(ch, width=20)
e2.pack()
sb = Button(ch, text="save", command=save_changes).pack()
def save_changes(): # function to change data in the txt file
global e1, e2
data = e1.get() + "\n" + e2.get() # removed space after \n
with open("pass.txt", "w") as f:
f.writelines(data)
root= Tk()
log = Toplevel()
root.geometry("350x350")
log.geometry("200x200")
entry1 = Entry(log)
entry2 = Entry(log)
button1 = Button(log, text="Login", command=login_in) #Login button
entry1.pack()
entry2.pack()
button1.pack()
label = Label(root, text="welcome").pack()
butt = Button(root, text="change data in file", command=change_login).pack()
root.withdraw()
root.mainloop()
以下是使用第二个选项的代码示例:
import sys
from tkinter import messagebox
from tkinter import *
now = open("pass.txt","w+")
now.write("user\n")
now.write("python3")
now.close()
def login_in():
with open("pass.txt") as f:
new = f.readlines()
name = new[0].rstrip()
password = new[1].rstrip()
if entry1.get() == name and entry2.get() == password:
root.deiconify()
log.destroy()
else:
messagebox.showerror("error","login Failed")
def change_login():
ch = Toplevel(root)
ch.geometry('300x300')
e1 = Entry(ch, width=20)
e1.pack()
e2 = Entry(ch, width=20)
e2.pack()
Button(ch, text="save", command=lambda e1=e1, e2=e2: save_changes(e1, e2)).pack()
def save_changes(e1, e2): # function to change data in the txt file
data = e1.get() + "\n" + e2.get() # removed space after \n
with open("pass.txt", "w") as f:
f.writelines(data)
root= Tk()
log = Toplevel()
root.geometry("350x350")
log.geometry("200x200")
entry1 = Entry(log)
entry2 = Entry(log)
button1 = Button(log, text="Login", command=login_in) #Login button
entry1.pack()
entry2.pack()
button1.pack()
label = Label(root, text="welcome").pack()
butt = Button(root, text="change data in file", command=change_login).pack()
root.withdraw()
root.mainloop()
以下是转换为类并使用类属性避免使用全局变量的代码示例。
import sys
from tkinter import messagebox
from tkinter import *
class MyApp(Frame):
def __init__(self, master, *args, **kwargs):
Frame.__init__(self, master, *args, **kwargs)
self.master = master
self.master.withdraw()
self.log = Toplevel()
self.master.geometry("350x350")
self.log.geometry("200x200")
self.entry1 = Entry(self.log)
self.entry2 = Entry(self.log)
self.button1 = Button(self.log, text="Login", command=self.login_in)
self.entry1.pack()
self.entry2.pack()
self.button1.pack()
Label(root, text="welcome").pack()
Button(root, text="change data in file", command=self.change_login).pack()
def login_in(self):
with open("pass.txt") as f:
new = f.readlines()
name = new[0].rstrip()
password = new[1].rstrip()
if self.entry1.get() == name and self.entry2.get() == password:
self.master.deiconify()
self.log.destroy()
else:
messagebox.showerror("error","login Failed")
def change_login(self):
ch = Toplevel(self.master)
ch.geometry('300x300')
self.e1 = Entry(ch, width=20)
self.e1.pack()
self.e2 = Entry(ch, width=20)
self.e2.pack()
Button(ch, text="save", command=self.save_changes).pack()
def save_changes(self):
data = "{}\n{}".format(self.e1.get(), self.e2.get())
with open("pass.txt", "w") as f:
f.writelines(data)
if __name__ == "__main__":
now = open("pass.txt","w+")
now.write("user\n")
now.write("python3")
now.close()
root = Tk()
app = MyApp(root)
root.mainloop()