PasswordBox does not assume style

问题:

I have the following style definitions:

<!-- Border -->
<Style x:Key="MyControlBorder" TargetType="{x:Type Border}">
    <Setter Property="BorderBrush" Value="DarkKhaki" />
    <Setter Property="Background" Value="White" />
    <Setter Property="BorderThickness" Value="1" />
    <Setter Property="CornerRadius" Value="10" />
</Style>

<!-- TextBox -->
<Style x:Key="MyTextBox" TargetType="{x:Type TextBox}">
    <Setter Property="Height" Value="30" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type TextBoxBase}">
                <Border Name="TextBoxBorder" Style="{StaticResource MyControlBorder}">
                    <ScrollViewer x:Name="PART_ContentHost"/>
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

<!-- PasswordBox -->
<Style x:Key="MyPasswordBox" TargetType="{x:Type PasswordBox}">
    <Setter Property="Height" Value="30" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type Control}">
                <Border Name="Border" Style="{StaticResource MyControlBorder}">
                    <ScrollViewer x:Name="PART_ContentHost" />
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

and the following xaml code:

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="*" />
        <RowDefinition Height="*" />
    </Grid.RowDefinitions>
    <TextBox Grid.Row="0" Style="{StaticResource MyTextBox}" />
    <PasswordBox Grid.Row="1" Style="{StaticResource MyPasswordBox}" />
</Grid>

Now i got this results:

The TextBox assume the style correctly, but why the PasswordBox does not assume the style?

回答1:

Somehow Border within ControlTemplate of PasswordBox does not take MyControlBorder style.

When you modify MyPasswordBox style like this... then it will work.

<Style x:Key="MyPasswordBox" TargetType="{x:Type PasswordBox}">
<Setter Property="Height" Value="30" />
<Setter Property="Template">
    <Setter.Value>
        <ControlTemplate TargetType="{x:Type Control}">
            <Border Name="Border" BorderBrush="DarkKhaki" Background="White" BorderThickness="1" CornerRadius="10">
                <ScrollViewer x:Name="PART_ContentHost" />
            </Border>
        </ControlTemplate>
    </Setter.Value>
</Setter>

I know it's not the best solution... but I can't figure out why MyControlBorder is not applied. It doesn't even work when you get rid of MyTextBox style. Then you are left only with MyControlBorder and MyPasswordBox ...it does not work either.

回答2:

If you wrap the Border in another Border everything just works as expected (I don't know why).

As a bonus, you can now have PasswordBoxes and TextBoxes "inherit" from the same Style, keeping things nice and DRY.

<!-- Border Style Definition -->
<Style x:Key="MyControlBorder" TargetType="Border">
    <Setter Property="BorderBrush" Value="DarkKhaki" />
    <Setter Property="Background" Value="White" />
    <Setter Property="BorderThickness" Value="1" />
    <Setter Property="CornerRadius" Value="10" />
</Style>

<!-- TextBox and PasswordBox Style -->
<Style x:Key="MyControlInputBox" TargetType="Control">
    <Setter Property="Height" Value="30" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type Control}">
                <Border>
                    <Border Name="Border" Style="{StaticResource MyControlBorder}">
                        <ScrollViewer x:Name="PART_ContentHost" />
                    </Border>
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

<!-- TextBox -->
<Style x:Key="MyTextBox" TargetType="{x:Type TextBox}" BasedOn="{StaticResource MyControlInputBox}" />

<!-- PasswordBox -->
<Style x:Key="MyPasswordBox" TargetType="{x:Type PasswordBox}" BasedOn="{StaticResource MyControlInputBox}" />