Question

我有一个密码框，我正在添加一个“显示密码”按钮（如图所示）：

密码文本框的相关XAML如下所示：

                <Border VerticalAlignment="Center" Grid.Row="2" Margin="2" Grid.Column="1" 
                    BorderThickness="1" 
                    BorderBrush="Black" 
                    Background="White">
                <Grid>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="*" />
                        <ColumnDefinition Width="Auto" />
                    </Grid.ColumnDefinitions>
                    <PasswordBox Name="txtPassword" Grid.Column="0" MaxLength="100" Margin="2" BorderThickness="0" GotFocus="txtPassword_GotFocus" PasswordChanged="txtPassword_PasswordChanged" />
                    <TextBox Name="txtVisiblePassword" Grid.Column="0" MaxLength="100" Margin="2" BorderThickness="0" Visibility="Collapsed" Height="22" />
                    <Button Grid.Column="1" Style="{StaticResource LightHoverButton}" x:Name="btnShowPassword" PreviewMouseDown="btnShowPassword_PreviewMouseDown" PreviewMouseUp="btnShowPassword_PreviewMouseUp">
                        <Image Source="{StaticResource ShowPassword_128}" Style="{StaticResource Image_16}" Margin="3,0" />
                    </Button>
                </Grid>
            </Border>

背后的相关代码：

    private void txtPassword_PasswordChanged(object sender, RoutedEventArgs e)
    {
        //Can show password is set to false if the password being displayed has been 
        //placed there automatically because the password is being remembered
        if (canshowpassword == false && string.IsNullOrEmpty(txtPassword.Password))
            canshowpassword = true;
        if (canshowpassword)
            btnShowPassword.Visibility = string.IsNullOrEmpty(txtPassword.Password) ? Visibility.Collapsed : Visibility.Visible;
        else
            btnShowPassword.Visibility = Visibility.Collapsed;
    }

我遇到的问题是，有一个“记住密码”选项，我不希望用户能够看到密码，除非密码文本框已被“清除”所有文本至少一次（以防止用户看到自动放在那里的全部或部分密码。上面的代码很接近，但是，它有一个问题，如果用户选择所有文本，然后按一个键开始一个新密码，“空”密码不会通过密码更改事件和“显示密码”按钮不会变得可见。用户必须删除所有文本，然后再次开始输入。我想了解用户选择所有文本并开始输入的情况。

如果我预览Key down事件，PasswordBox上没有“SelectedText”属性，所以我不知道如何在添加新文本之前清除密码是否会被清除。

有没有办法知道PasswordBox密码已被清除，和/或知道是否所有文本都被选中了？

Answer 1

这个非常棘手。他们没有公开披露这些信息，但你可以反思一下。这有点令人讨厌，因为他们试图用内部类和私有属性隐藏所有东西，但是你走了：

#The main function definition

def main():
    Name = input("What is your name?  ")
    Account_ID = input("What is your account ID?  ")
    Transaction_Code = input("Press W or w for Withdrawal, Press D or d for Deposit:  ")
    Previous_Balance = float(input("What is your previous balance?  "))
    Transaction_Amount = float(input("How much is the transaction amount?  "))

    if Transaction_Code == "W" or Transaction_Code == "w":
        Withdrawal_Process(Previous_Balance, Transaction_Amount)
    elif Transaction_Code == "D" or Transaction_Code == "d":
        Deposit_Process(Previous_Balance, Transaction_Amount)
    else:
        Process_Invalid_Code(Previous_Balance)

#Defines the Deposit Process

def Deposit_Process(Previous_Balance, Transaction_Amount):
    New_Balance = Transaction_Amount + Previous_Balance
    Print_Function(New_Balance)


#Defines the Withdrawal Process

def Withdrawal_Process(Previous_Balance, Transaction_Amount):
    if Transaction_Amount > Previous_Balance:
        print("Invalid Transaction: Not Sufficient Funds!")
        New_Balance = Previous_Balance
        Print_Function(New_Balance) 
    else:
        New_Balance = Previous_Balance - Transaction_Amount
        Print_Function(New_Balance)

#The Invalid Code Function Definition

def Process_Invalid_Code(Previous_Balance):
    New_Balance = Previous_Balance
    print ("Invalid Transaction Code!")
    print ("Please type W or w for Withdrawal")
    print ("or type D or d for Deposit")
    Print_Function(New_Balance)


#Defines the Print Function

def Print_Function(New_Balance):
    print ("Your balance is now $", format(New_Balance, '.2f'))  


#Call the main function

main()

当然，你应该缓存一些反思内容，但我会把它留给你：）。

注意：您需要在textBox_PreviewKeyDown（）中开始和结束。到达PasswordChanged时，选择已经明显丢失。如果要检查是否选中了整个密码，则需要检查0 ==＆gt; LEN。

如何在PasswordBox中获取突出显示的文本

1 个答案: