有時候項目中會遇到需要提示資訊的文本框和密碼框。例如登入的時候提升“請輸入密碼”“請輸入登入名之類的”。在這兒就寫一下，以備将來查用。
首先來看一下帶提示的TextBox：
首先，在項目中建立一個使用者控件，
xaml如下：
<TextBox x:Class="SampleControls.Controls.HintTextbox"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d" x:Name="textBox"
d:DesignHeight="300" d:DesignWidth="300">
<TextBox.Resources>
<VisualBrush x:Key="HelpBrush" TileMode="None" Opacity="0.3" Stretch="None" AlignmentY="Center" AlignmentX="Left" ViewportUnits="RelativeToBoundingBox">
<VisualBrush.Viewport>
<Rect X="0.01" Y="0" Width="1" Height="1" ></Rect>
</VisualBrush.Viewport>
<VisualBrush.Visual>
<TextBlock VerticalAlignment="Stretch" HorizontalAlignment="Stretch" Grid.Column="1" Text="{Binding Hint, ElementName=textBox}" Padding="10,0,0,0"
Width="{Binding ElementName=textBox,Path=ActualWidth}"/>
</VisualBrush.Visual>
</VisualBrush>
</TextBox.Resources>
<TextBox.Style>
<Style TargetType="TextBox">
<Setter Property="Background" Value="{Binding ElementName=textBox, Path=Background}"></Setter>
<Style.Triggers>
<Trigger Property="Text" Value="{x:Null}">
<Setter Property="Background" Value="{StaticResource HelpBrush}"/>
</Trigger>
<Trigger Property="Text" Value="">
<Setter Property="Background" Value="{StaticResource HelpBrush}"/>
</Trigger>
</Style.Triggers>
</Style>
</TextBox.Style>
</TextBox>
對應的.cs内容如下
public partial class HintTextbox : TextBox
{
public HintTextbox()
{
InitializeComponent();
}
/// <summary>
/// 文本框提示文字
/// </summary>
public string Hint
{
get { return (string)GetValue(HintProperty); }
set { SetValue(HintProperty, value); }
}
// Using a DependencyProperty as the backing store for Hint. This enables animation, styling, binding, etc...
public static readonly DependencyProperty HintProperty =
DependencyProperty.Register("Hint", typeof(string), typeof(HintTextbox), new PropertyMetadata(null));
}
PasswordBox
因為passwordBox中的Password不是依賴屬性，是以有的時候需要綁定的時候就沒法 實作，在這兒定義一個附加屬性來實作綁定，
public class PasswordBoxHelper
{
public static bool GetIsPasswordBindingEnabled(DependencyObject obj)
{
return (bool)obj.GetValue(IsPasswordBindingEnabledProperty);
}
public static void SetIsPasswordBindingEnabled(DependencyObject obj, bool value)
{
obj.SetValue(IsPasswordBindingEnabledProperty, value);
}
// Using a DependencyProperty as the backing store for IsPasswordBindingEnabled. This enables animation, styling, binding, etc...
public static readonly DependencyProperty IsPasswordBindingEnabledProperty =
DependencyProperty.RegisterAttached("IsPasswordBindingEnabled", typeof(bool),
typeof(PasswordBoxHelper),
new UIPropertyMetadata(false, OnIsPasswordBindingEnableChanged));
private static void OnIsPasswordBindingEnableChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
PasswordBox passwordBox = d as PasswordBox;
if (passwordBox != null)
{
passwordBox.PasswordChanged -= passwordBox_PasswordChanged;
if ((bool)e.NewValue)
{
passwordBox.PasswordChanged += passwordBox_PasswordChanged;
}
}
}
static void passwordBox_PasswordChanged(object sender, RoutedEventArgs e)
{
PasswordBox passwordBox = (PasswordBox)sender;
if (!string.Equals(GetBindedPassword(passwordBox), passwordBox.Password))
{
SetBindedPassword(passwordBox, passwordBox.Password);
}
}
public static string GetBindedPassword(DependencyObject obj)
{
return (string)obj.GetValue(BindedPasswordProperty);
}
public static void SetBindedPassword(DependencyObject obj, string value)
{
obj.SetValue(BindedPasswordProperty, value);
}
// Using a DependencyProperty as the backing store for BindedPassword. This enables animation, styling, binding, etc...
public static readonly DependencyProperty BindedPasswordProperty =
DependencyProperty.RegisterAttached("BindedPassword",
typeof(string), typeof(PasswordBoxHelper),
new UIPropertyMetadata(string.Empty, OnBindedPasswordChanged));
private static void OnBindedPasswordChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
PasswordBox passwordBox = d as PasswordBox;
if (passwordBox != null && !string.Equals(GetBindedPassword(passwordBox), passwordBox.Password))
{
passwordBox.Password = e.NewValue == null ? string.Empty : e.NewValue.ToString();
}
}
然後同樣定義一個使用者控件
xaml如下：
<UserControl x:Class="SampleControls.Controls.HintPasswordBox"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:help="clr-namespace:SampleControls.Help"
mc:Ignorable="d" x:Name="uc"
d:DesignHeight="300" d:DesignWidth="300">
<Grid>
<PasswordBox x:Name="password" help:PasswordBoxHelper.IsPasswordBindingEnabled="true" FontSize="{Binding ElementName=uc,Path=FontSize}"
help:PasswordBoxHelper.BindedPassword="{Binding Path=Password,ElementName=uc,Mode=TwoWay}">
<PasswordBox.Background>
<VisualBrush TileMode="None" Opacity="0.3" Stretch="None" AlignmentY="Center" AlignmentX="Left" ViewportUnits="RelativeToBoundingBox">
<VisualBrush.Viewport>
<Rect X="0.01" Y="0" Width="1" Height="1" ></Rect>
</VisualBrush.Viewport>
<VisualBrush.Visual>
<TextBlock VerticalAlignment="Stretch" HorizontalAlignment="Stretch" Grid.Column="1" Text="{Binding HintText, ElementName=uc}" Padding="10,0,0,0"
Width="{Binding ElementName=uc,Path=ActualWidth}" FontSize="{Binding ElementName=uc,Path=FontSize}"/>
</VisualBrush.Visual>
</VisualBrush>
</PasswordBox.Background>
</PasswordBox>
</Grid>
</UserControl>
.cs如下：
public partial class HintPasswordBox : UserControl
{
public HintPasswordBox()
{
InitializeComponent();
}
public string Hint
{
get { return (string)GetValue(HintProperty); }
set { SetValue(HintProperty, value); }
}
// Using a DependencyProperty as the backing store for Hit. This enables animation, styling, binding, etc...
public static readonly DependencyProperty HintProperty =
DependencyProperty.Register("Hint", typeof(string), typeof(HintPasswordBox), new PropertyMetadata(null, new PropertyChangedCallback(OnHintChanged)));
private static void OnHintChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
HintPasswordBox password = d as HintPasswordBox;
password.UpdateStates();
}
public string HintText
{
get { return (string)GetValue(HintTextProperty); }
set { SetValue(HintTextProperty, value); }
}
// Using a DependencyProperty as the backing store for HintText. This enables animation, styling, binding, etc...
public static readonly DependencyProperty HintTextProperty =
DependencyProperty.Register("HintText", typeof(string), typeof(HintPasswordBox), new PropertyMetadata(null));
public string Password
{
get { return (string)GetValue(PasswordProperty); }
set { SetValue(PasswordProperty, value); }
}
// Using a DependencyProperty as the backing store for Password. This enables animation, styling, binding, etc...
public static readonly DependencyProperty PasswordProperty =
DependencyProperty.Register("Password", typeof(string), typeof(HintPasswordBox), new PropertyMetadata(null, new PropertyChangedCallback(OnPasswordChanged)));
private static void OnPasswordChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
HintPasswordBox uc = d as HintPasswordBox;
uc.UpdateStates();
}
private void UpdateStates()
{
if (string.IsNullOrWhiteSpace(Password))
{
HintText = Hint;
}
else
{
HintText = "";
}
}
源代碼：http://download.csdn.net/detail/yulongguiziyao/8352581
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