Style Trigger on Passwordbox

问题:

I'm using the following style on a Textbox so that it has text and a background colour until someone tries to enter data into it. Works fine but my problem arises because it is a login screen and my other control is a Passwordbox which won't let me access the Password property (which is the equivalent to the Text property of the Textbox). Any advice on how I would work around this?

<Style TargetType="TextBox" xmlns:sys="clr-namespace:System;assembly=mscorlib">
            <Style.Resources>
                <VisualBrush x:Key="CueBannerBrush" AlignmentX="Left" AlignmentY="Center" Stretch="None">
                    <VisualBrush.Visual>
                        <Label Content="Search" Foreground="LightGray"/>
                    </VisualBrush.Visual>
                </VisualBrush>
            </Style.Resources>
            <Style.Triggers>
                <Trigger Property="Text" Value="{x:Static sys:String.Empty}">
                    <Setter Property="Background" Value="{StaticResource CueBannerBrush}" />
                </Trigger>
                <Trigger Property="Text" Value="{x:Null}">
                    <Setter Property="Background" Value="{StaticResource CueBannerBrush}" />
                </Trigger>
                <Trigger Property="IsKeyboardFocused" Value="True">
                    <Setter Property="Background" Value="White" />
            </Trigger>
            </Style.Triggers>
            <Setter Property="Control.Foreground" Value="#4C2C66"/>
            <Setter Property="VerticalAlignment" Value="Center"/>
        </Style>

回答1:

If you are using a PasswordBox, make sure to change the TargetType and use a DataTrigger:

<Style TargetType="{x:Type PasswordBox}" xmlns:sys="clr-namespace:System;assembly=mscorlib">
            <Style.Resources>
                <VisualBrush x:Key="CueBannerBrush" AlignmentX="Left" AlignmentY="Center" Stretch="None">
                    <VisualBrush.Visual>
                        <Label Content="Search" Foreground="LightGray"/>
                    </VisualBrush.Visual>
                </VisualBrush>
            </Style.Resources>
            <Style.Triggers>
                <DataTrigger Binding="{Binding Path=Password}" Value="{x:Null}">
                    <Setter Property="Background" Value="{StaticResource CueBannerBrush}" />
                </DataTrigger>

                <Trigger Property="IsKeyboardFocused" Value="True">
                    <Setter Property="Background" Value="White" />
                </Trigger>
            </Style.Triggers>
            <Setter Property="Control.Foreground" Value="#4C2C66"/>
            <Setter Property="VerticalAlignment" Value="Center"/>
       </Style>