如果用户在密码框中输入 1985，将显示四个项目符号 (●●●●)。如何在几秒钟内显示输入的每个字母或数字，然后将其更改为项目符号？我想这不能在密码框中完成，但是还有其他方法吗？
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22022 次
3 回答
19
在密码框顶部放置一个文本框，然后使用一些数据绑定和动画。只要有输入，这块 XAML 将允许文本框可见，但是一旦输入停止，文本框就会消失，只留下显示密码字符的密码框。
<Window.Resources>
<Storyboard x:Key="Storyboard1">
<DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Opacity)" Storyboard.TargetName="textBox">
<EasingDoubleKeyFrame KeyTime="0" Value="1"/>
<EasingDoubleKeyFrame KeyTime="0:0:0.6" Value="1"/>
<EasingDoubleKeyFrame KeyTime="0:0:1.2" Value="0"/>
</DoubleAnimationUsingKeyFrames>
</Storyboard>
</Window.Resources>
<Window.Triggers>
<EventTrigger RoutedEvent="TextBoxBase.TextChanged" SourceName="textBox">
<StopStoryboard BeginStoryboardName="Storyboard1_BeginStoryboard"/>
<BeginStoryboard x:Name="Storyboard1_BeginStoryboard" Storyboard="{StaticResource Storyboard1}"/>
</EventTrigger>
</Window.Triggers>
<PasswordBox x:Name="passwordBox"/>
<TextBox x:Name="textBox"
Text="{Binding ElementName=passwordBox, Path=Password, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
Opacity="100"/>
您可以在动画中使用 KeyTimes 来获得您喜欢的延迟。您还可以更改文本框中的字体设置，以使键入的文本和密码字符更好地对齐。
编辑
如果您只想将键入的最后一个字符显示为明文：
这种情况有点不同，需要更多的复杂性。此方案仅使用窗口上的文本框，而不使用密码框。
<TextBox Name="tbxPwd" Margin="20,0"
Text="{Binding Path=DisplayedPwd}" />
在窗口的代码隐藏中（或在 ViewModel 类中），您将需要两个属性，ActualPwd并且DisplayedPwd. 文本框绑定到该DisplayedPwd属性。
在代码隐藏中，您将需要以下代码：
Private Sub tbxPwd_PreviewKeyDown(sender As Object, e As System.Windows.Input.KeyEventArgs) _
Handles tbxPwd.PreviewKeyDown
If e.Key = Key.Back Then
If ActualPwd.Length > 0 Then
//Remove the last character.
ActualPwd = ActualPwd.Substring(0, ActualPwd.Length - 1)
ShowLastCharacter()
tbxPwd.CaretIndex = DisplayedPwd.Length
End If
End If
End Sub
Private Sub tbxPwd_PreviewTextInput(sender As Object, e As System.Windows.Input.TextCompositionEventArgs) _
Handles tbxPwd.PreviewTextInput
ActualPwd &= e.Text
e.Handled = True
ShowLastCharacter()
tbxPwd.CaretIndex = DisplayedPwd.Length
End Sub
Private Sub ShowLastCharacter()
Dim lastChar As Char = ActualPwd.Substring(ActualPwd.Length - 1)
//Reset the displayed pwd.
DisplayedPwd = ""
For i As Int32 = 0 To ActualPwd.Length - 2
DisplayedPwd &= "•"
Next
DisplayedPwd &= lastChar
End Sub
tbxPwd_PreviewTextInput 方法用于检索用户键入的字符。tbxPwd_PreviewKeyDown 方法用于检索 BackSpace 键或您想要检测的任何其他控制字符键。
此代码没有延迟，因此它始终以明文形式显示密码字符串的最后一个字符。应该很容易添加一些代码以及 Timer，以便在延迟一段时间后将最后一个字符更改为 pwd 字符。
上面的代码还没有经过彻底的调试，所以如果用户退格了他们的整个密码重新开始，可能会出现问题。
提示：Alt+0149 显示“子弹”密码字符。
于 2011-07-08T19:08:20.007 回答
2
只需使用一个TextBox. 请看下面的代码：
窗口的 XAML 代码：
<Label x:Name="Pwd" Height="30" Width="70" HorizontalAlignment="Left" FontSize="14"
Margin="10,10,0,0" VerticalAlignment="Top" Content="Password:"/>
<TextBox x:Name="textBox" Width="130" Height="30" Margin="30,10,0,0"
VerticalAlignment="Top" MaxLength="12" FontSize="14"
PreviewKeyDown="TextBox_PreviewKeyDown"
KeyDown="TextBox_KeyDown" />
<CheckBox x:Name="ckhShowPassword" Height="30"
Content="Show password characters"
Margin="69,0,59,42" VerticalAlignment="Bottom"
Checked="ckhShowPassword_Checked" Unchecked="ckhShowPassword_UnChecked"/>
<Label x:Name="lblActualPwd" Height="30" Width="200"
Margin="10,100,0,0" VerticalAlignment="Top" FontSize="14"
HorizontalAlignment="Center" HorizontalContentAlignment="Center"/>
后面的 C# 代码：
#region "CLASS LEVEL VARIABLES"
System.Windows.Threading.DispatcherTimer dispatcherTimer =
new System.Windows.Threading.DispatcherTimer();
string actualPwd = "";
#endregion
#region "WINDOW EVENTS"
public Window2()
{
InitializeComponent();
}
private void Window2_Loaded(object sender, RoutedEventArgs e)
{
lblActualPwd.Visibility = Visibility.Hidden;
textBox.Focus();
}
#endregion
#region "TEXTBOX EVENTS"
private void TextBox_PreviewKeyDown(object sender, KeyEventArgs e)
{
if (e.Key != Key.Back)
{
actualPwd += GetCharFromKey(e.Key); //Store actual characters for later retrieval
}
else if (e.Key == Key.Back)
{
if (actualPwd.Length > 0)
actualPwd = actualPwd.Remove(actualPwd.Length - 1);
else
actualPwd = "";
}
else
{
actualPwd += GetCharFromKey(e.Key);
}
string str = "";
for (int i = 0; i < textBox.Text.Length; i++)
str += char.ConvertFromUtf32(8226);
textBox.Text = str;
textBox.Select(textBox.Text.Length, 0);
}
private void TextBox_KeyDown(object sender, KeyEventArgs e)
{
dispatcherTimer.Tick += new EventHandler(dispatcherTimer_Tick);
dispatcherTimer.Interval = new TimeSpan(0, 0, 0, 1);
dispatcherTimer.Start();
}
#endregion
#region "DISPATCHER EVENT"
private void dispatcherTimer_Tick(object sender, EventArgs e)
{
string str = "";
for(int i = 0; i < textBox.Text.Length; i++)
str += char.ConvertFromUtf32(8226);
textBox.Text = str;
textBox.Select(textBox.Text.Length, 0);
}
#endregion
#region "CHECKBOX EVENTS"
private void ckhShowPassword_Checked(object sender, RoutedEventArgs e)
{
if (actualPwd.Length > 0)
{
lblActualPwd.Foreground = Brushes.Blue;
lblActualPwd.Content = actualPwd;
lblActualPwd.Visibility = Visibility.Visible;
}
else
{
lblActualPwd.Foreground = Brushes.Red;
lblActualPwd.Content = "Please input password.";
lblActualPwd.Visibility = Visibility.Visible;
}
}
private void ckhShowPassword_UnChecked(object sender, RoutedEventArgs e)
{
lblActualPwd.Content = string.Empty;
lblActualPwd.Visibility = Visibility.Hidden;
}
#endregion
#region "ENUM TYPE - MAP KEY TO CHARACTER"
public enum MapType : uint
{
MAPVK_VK_TO_VSC = 0x0,
MAPVK_VSC_TO_VK = 0x1,
MAPVK_VK_TO_CHAR = 0x2,
MAPVK_VSC_TO_VK_EX = 0x3,
}
#endregion
#region "INTEROP DLL IMPORT"
[DllImport("user32.dll")]
public static extern bool GetKeyboardState(byte[] lpKeyState);
[DllImport("user32.dll")]
public static extern uint MapVirtualKey(uint uCode, MapType uMapType);
[DllImport("user32.dll")]
#endregion
#region "VIRTUAL KEY UNICODE CONVERSION"
public static extern int ToUnicode(
uint wVirtKey,
uint wScanCode,
byte[] lpKeyState,
[Out, MarshalAs(UnmanagedType.LPWStr, SizeParamIndex = 4)]
StringBuilder pwszBuff,
int cchBuff,
uint wFlags);
#endregion
#region "FUNCTION - CHAR FROM KEY"
public static char GetCharFromKey(Key key)
{
char ch = ' ';
int virtualKey = KeyInterop.VirtualKeyFromKey(key);
byte[] keyboardState = new byte[256];
GetKeyboardState(keyboardState);
uint scanCode = MapVirtualKey((uint)virtualKey, MapType.MAPVK_VK_TO_VSC);
StringBuilder stringBuilder = new StringBuilder(2);
int result = ToUnicode((uint)virtualKey, scanCode, keyboardState, stringBuilder, stringBuilder.Capacity, 0);
switch (result)
{
case -1:
break;
case 0:
break;
case 1:
{
ch = stringBuilder[0];
break;
}
default:
{
ch = stringBuilder[0];
break;
}
}
return ch;
}
#endregion
MapType enum从MapType检索
于 2013-03-09T00:04:32.867 回答
0
我已经实现了类似的功能，在这里作为一个更简单的示例，将密码框替换为文本框以在鼠标悬停密码框时显示密码，如下所示
窗口的xml代码
<PasswordBox Name="LicencePasswordBox" MouseEnter="LicencePasswordBox_MouseEnter"></PasswordBox>
<TextBox IsReadOnly="True" Name="LicencePasswordTextBox" MouseLeave="LicencePasswordBox_MouseLeave" Visibility="Hidden"></TextBox>
c#代码后面
private void LicencePasswordBox_MouseEnter(object sender, MouseEventArgs e)
{
LicencePasswordBox.Visibility = Visibility.Hidden;
LicencePasswordTextBox.Visibility = Visibility.Visible;
}
private void LicencePasswordBox_MouseLeave(object sender, MouseEventArgs e)
{
LicencePasswordBox.Visibility = Visibility.Visible;
LicencePasswordTextBox.Visibility = Visibility.Hidden;
}
此外，如果您正在开发 mvp 或 mvp-vm wpf 应用程序，请不要忘记在后面的代码中将传入的值绑定到 LicencePasswordBox 和 LicencePasswordTextBox
于 2017-04-25T06:38:09.910 回答