How to change TextBox placeholder text color for a specific element, not global

Question

MSDN lists the styles and templates for the TextBox class here. I can override these theme resources by creating a ResourceDictionary in App.

Answer 1

Old question I know, but I found it incredibly fruststrating that I had to create an entire copy of the TextBox style just to edit the placeholder color of one or two TextBox elements.

So I created this method, which can be used on individual TextBoxes as required:

public static void SetPlaceholderColor(TextBox textBox, Color color)
{
    var textBoxContentGrid = VisualTreeHelper.GetChild(textBox, 0) as Grid;
    for (var i = 0; i < VisualTreeHelper.GetChildrenCount(textBoxContentGrid); i++)
    {
        var visualChild = VisualTreeHelper.GetChild(textBoxContentGrid, i);
        if ((string) visualChild.GetValue(FrameworkElement.NameProperty) != "PlaceholderTextContentPresenter") 
            continue;
        var placeHolderContentControl = visualChild as ContentControl;
        if (placeHolderContentControl != null)
            placeHolderContentControl.Foreground = new SolidColorBrush(color);
    }
}

This should also work for PasswordBoxes, since the TextBox parameter should easily be replacable with just "FrameworkElement"

Answer 2

Assuming you are using MSDN Textbox Style

Resource Remove Foreground Property from Contencontrol in Template<ContentControl Foreground="{ThemeResource TextBoxPlaceholderTextThemeBrush}"/>

<Page.Resources>
    <!--From MSDN : Default style for Windows.UI.Xaml.Controls.TextBox -->
    <Style x:Key="MsdnTextboxStyle" TargetType="TextBox">          
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="TextBox">
                 .....
                 .....
                <ContentControl x:Name="PlaceholderTextContentPresenter"
                              Grid.Row="1"                          
                              Margin="{TemplateBinding BorderThickness}"
                              Padding="{TemplateBinding Padding}"
                              IsTabStop="False"
                              Grid.ColumnSpan="2"
                              Content="{TemplateBinding PlaceholderText}" 
                              IsHitTestVisible="False"/>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>           
</Page.Resources> 

Xaml

 <StackPanel Orientation="Horizontal">
    <TextBox  PlaceholderText="PlaceholderText here..." Style="{StaticResource MsdnTextboxStyle}" Margin="20"  Foreground="Red" Height="30" Width="120">
        <TextBox.Resources>
            <Style TargetType="ContentControl">
                <Setter Property="Foreground" Value="Green"/>
            </Style>
        </TextBox.Resources>
    </TextBox>
    <TextBox  PlaceholderText="PlaceholderText here..." Style="{StaticResource MsdnTextboxStyle}" Margin="20"  Foreground="Red" Height="30" Width="120">
        <TextBox.Resources>
            <Style TargetType="ContentControl">
                <Setter Property="Foreground" Value="Red"/>
            </Style>
        </TextBox.Resources>
    </TextBox>
    <TextBox  PlaceholderText="PlaceholderText here..." Style="{StaticResource MsdnTextboxStyle}" Margin="20"  Foreground="Red" Height="30" Width="120">
        <TextBox.Resources>
            <Style TargetType="ContentControl">
                <Setter Property="Foreground" Value="Blue"/>
            </Style>
        </TextBox.Resources>
    </TextBox>
</StackPanel>

Update

Resource

Remove Foreground Property from Contencontrol in Template<ContentControl Foreground="{ThemeResource TextBoxPlaceholderTextThemeBrush}"/>

<Page.Resources>
    <ResourceDictionary>
        <ResourceDictionary.ThemeDictionaries>
            <ResourceDictionary x:Key="Default">
                <SolidColorBrush x:Key="ContentControlForeGround" Color="Red"></SolidColorBrush>
                <SolidColorBrush x:Key="ContentControlForeGround1" Color="Yellow"></SolidColorBrush>
            </ResourceDictionary>
            <ResourceDictionary x:Key="Light">
                <SolidColorBrush x:Key="ContentControlForeGround" Color="Blue"></SolidColorBrush>
                <SolidColorBrush x:Key="ContentControlForeGround1" Color="SkyBlue"></SolidColorBrush>
            </ResourceDictionary>
            <ResourceDictionary x:Key="Dark">
                <SolidColorBrush x:Key="ContentControlForeGround" Color="Green"></SolidColorBrush>
                <SolidColorBrush x:Key="ContentControlForeGround1" Color="Chocolate"></SolidColorBrush>
            </ResourceDictionary>
        </ResourceDictionary.ThemeDictionaries>
        <Style x:Key="TextBoxStyle1" TargetType="TextBox">
          .....
           <ContentControl x:Name="PlaceholderTextContentPresenter" Grid.ColumnSpan="2" Content="{TemplateBinding PlaceholderText}"  IsHitTestVisible="False" IsTabStop="False" Margin="{TemplateBinding BorderThickness}" Padding="{TemplateBinding Padding}" Grid.Row="1"/>
           ......                                                       
        </Style>
    </ResourceDictionary>
</Page.Resources>

xaml

<StackPanel Orientation="Horizontal">
    <TextBox  Style="{StaticResource TextBoxStyle1}" PlaceholderText="PlaceholderText here..."  Margin="20"  Foreground="Red" Height="30" Width="170">
        <TextBox.Resources>
            <Style TargetType="ContentControl">
                <Setter Property="Foreground" Value="{StaticResource ContentControlForeGround}"></Setter>
            </Style>
        </TextBox.Resources>
    </TextBox>
    <TextBox  Style="{StaticResource TextBoxStyle1}" PlaceholderText="PlaceholderText here..."  Margin="20"  Foreground="Red" Height="30" Width="170">
        <TextBox.Resources>
            <Style TargetType="ContentControl">
                <Setter Property="Foreground" Value="{StaticResource ContentControlForeGround1}"></Setter>
            </Style>
        </TextBox.Resources>
    </TextBox>
</StackPanel>