[英]How to make TextBox to use password characters instead of using passwordbox in wpf?
[英]Using a textbox as a passwordbox with a password char set in wpf
我在尝试使用密码字符和占位符设置文本框时遇到问题。 我已经为用户名做了一个,效果很好,但我对密码框能做什么感到困惑。
我知道你可以有一个带有密码字符的密码框,但你不能在 wpf 中也有一个占位符。
我有这个用户名,我想对密码框做同样的事情:
this.usernameTxt.Foreground = Brushes.LightGray;
this.usernameTxt.Text = "Username";
this.usernameTxt.GotKeyboardFocus += new KeyboardFocusChangedEventHandler(this.usernameTxt_Selected);
this.usernameTxt.PreviewLostKeyboardFocus += new KeyboardFocusChangedEventHandler(this.usernameTxt_Lostfocus);
public void usernameTxt_Lostfocus(object sender, EventArgs e)
{
if (string.IsNullOrEmpty(usernameTxt.Text))
{
this.usernameTxt.Text = "Username";
this.usernameTxt.Foreground = Brushes.LightGray;
}
}
public void usernameTxt_Selected(object sender, EventArgs e)
{
this.usernameTxt.Focus();
this.usernameTxt.SelectAll();
this.usernameTxt.Text = "";
this.usernameTxt.Foreground = Brushes.Black;
}
您可以查看以下变通办法。 在此示例中,我依靠嵌入在密码控件中的文本框控件的TextChanged事件。
触发TextChanged事件时,我使用堆栈来捕获最后输入的字符,然后在视图模型中维护一个混淆的密码以及一个实际的密码。 当按下删除或返回键时,我弹出从堆栈中输入的最后一个字符。
XAML:
<Window x:Class="WpfApplication1.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:WpfApplication1"
xmlns:converters="clr-namespace:WpfApplication1.Converters"
Title="MainWindow" Height="350" Width="525">
<Window.DataContext>
<local:ViewModel />
</Window.DataContext>
<Grid>
<PasswordBox x:Name="passwordBox" Height="20" PasswordChar="*" Width="200" Background="LightYellow" >
<PasswordBox.Template>
<ControlTemplate>
<TextBox x:Name="PasswordTextbox" GotFocus="GotFocus" Text="{Binding ObfuscatedPassword, Mode=TwoWay}" KeyUp="PasswordTextbox_KeyUp" TextAlignment="Center" Foreground="LightGray" />
</ControlTemplate>
</PasswordBox.Template>
</PasswordBox>
</Grid>
</Window>
视图模型:
namespace WpfApplication1
{
public class ViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private string obfuscatedPassword = "user name";
public string ObfuscatedPassword
{
get { return obfuscatedPassword; }
set
{
if (this.obfuscatedPassword != value)
{
this.obfuscatedPassword = value;
OnPropertyChanged();
}
}
}
private string actualPassword = null;
public string ActualPassword
{
get { return actualPassword; }
set
{
if (this.actualPassword != value)
{
this.actualPassword = value;
OnPropertyChanged();
}
}
}
private void OnPropertyChanged([CallerMemberName] string propertyName = "")
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
后台代码:
public partial class MainWindow : Window
{
ViewModel viewModel = null;
public MainWindow()
{
InitializeComponent();
this.viewModel = this.DataContext as ViewModel;
}
public string defaultText = "user name";
Stack<string> charStack = new Stack<string>();
private void PasswordTextbox_KeyUp(object sender, KeyEventArgs e)
{
var textbox = sender as TextBox;
textbox.Text = string.Empty;
var key = e.Key.ToString();
if (this.viewModel.ObfuscatedPassword == defaultText)
{
this.viewModel.ObfuscatedPassword = string.Empty;
}
var deleteLastCharacter = (e.Key == Key.Delete || e.Key == Key.Back);
if (deleteLastCharacter)
{
if (charStack.Count > 0)
{
charStack.Pop();
}
if (charStack.Count == 0)
{
textbox.Text = defaultText;
textbox.CaretIndex = defaultText.Length;
textbox.SelectAll();
e.Handled = true;
return;
}
}
else if (IsTextAllowed(key))
{
charStack.Push(key);
}
else
{
e.Handled = true;
return;
}
this.viewModel.ObfuscatedPassword = ObfuscatePassword();
this.viewModel.ActualPassword = ActualizePassword();
textbox.CaretIndex = this.viewModel.ObfuscatedPassword.Length;
e.Handled = true;
}
private static bool IsTextAllowed(string text)
{
Regex regex = new Regex(@"^.*(?=.{10,})(?=.*\d)(?=.*[a-z])(?=.*[A-Z])(?=.*[@#$%^&+=]).*$"); //regex that matches disallowed text
return !regex.IsMatch(text);
}
private string ActualizePassword()
{
var password = string.Empty;
foreach (var character in charStack.Reverse())
{
password += character;
}
return password;
}
private string ObfuscatePassword()
{
var password = string.Empty;
foreach (var character in charStack.Reverse())
{
password += passwordBox.PasswordChar;
}
return password;
}
private void GotFocus(object sender, RoutedEventArgs e)
{
if (this.viewModel.ObfuscatedPassword == defaultText)
{
this.viewModel.ObfuscatedPassword = string.Empty;
}
}
}
首先从这个链接下载密码点字体, https://github.com/davidagraf/passwd/blob/master/public/ttf/password.ttf
在此 put password.ttf 文件下添加名为“AppFonts”的文件夹,并将此字体的引用添加到您的 WPF 应用程序 App.xaml。 因此,您可以在全球范围内访问此字体。
<Application.Resources>
<ResourceDictionary>
<Style x:Key="CustomFont">
<Setter Property="TextElement.FontFamily" Value="/AppFonts/#password"></Setter>
</Style>
</ResourceDictionary>
</Application.Resources>
创建 PasswordViewModel 并下载 GalaSoft 的 nuget 包 MvvmLight。
using System;
using GalaSoft.MvvmLight;
public class PasswordViewModel : ViewModelBase
{
private string _PlainPassword { get; set; }
public string PlainPassword
{
get {
return _PlainPassword;
}
set
{
_PlainPassword = value;
RaisePropertyChanged("Password");
}
}
}
现在创建您的视图 PasswordUserControl.xaml 并将视图构造函数添加到 DataContext。
PasswordViewModel passwordModel= new PasswordViewModel();
this.DataContext = passwordModel;
并在查看 xaml 粘贴此
<Grid Margin="20,0,15,0" Height="45">
<TextBox Grid.Row="3" Name="txtPasswordEntry" Background="Transparent" Padding="12" Foreground="#787878" Height="45"
Text="{Binding PlainPassword,UpdateSourceTrigger=PropertyChanged,Mode=TwoWay}"
FontFamily="/WpfApplication;component/AppFonts/#Password" FontSize="14" FontWeight="Medium">
<TextBox.InputBindings>
<!--Disable CTRL+C (COPY) -->
<KeyBinding Command="ApplicationCommands.NotACommand" Key="C" Modifiers="Control" />
<!--Disable CTRL+X (CUT) -->
<KeyBinding Command="ApplicationCommands.NotACommand" Key="X" Modifiers="Control" />
</TextBox.InputBindings>
<TextBox.ContextMenu>
<!--Hide context menu where you could copy/cut as well -->
<ContextMenu Visibility="Collapsed" />
</TextBox.ContextMenu>
</TextBox>
<TextBlock IsHitTestVisible="False" Padding="13" Text="Password" Foreground="#787878" Height="45" FontSize="14" FontWeight="Medium">
<TextBlock.Style>
<Style TargetType="{x:Type TextBlock}">
<Setter Property="Visibility" Value="Collapsed"/>
<Style.Triggers>
<DataTrigger Binding="{Binding Text, ElementName=txtPasswordEntry}" Value="">
<Setter Property="Visibility" Value="Visible"/>
</DataTrigger>
</Style.Triggers>
</Style>
</TextBlock.Style>
</TextBlock>
</Grid>
注意:听到 FontFamily="/WpfApplication;component/AppFonts/#Password" WpfApplication 是您的应用程序名称。 或者您可以从文本框属性更改字体系列。
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