How to set label content dynamically(from code behind) in C# WPF

Question

0.00/5 (No votes)

See more:

I am creating textBox dynamically and applying style for watermark text. its working fine but, The text displayed as watermark label(Only Numeric) that is hard coded in my style that I want to set in code behind,
below are my style. I want to pass it from codebehind.
thanks.

What I have tried:

<Style x:Key="onlyNumericTextboxStyle" TargetType="{x:Type TextBox}">
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type TextBox}">
                        <Grid>
                            <Border Background="{TemplateBinding Background}" BorderBrush="#FF97A0A5" BorderThickness="1" SnapsToDevicePixels="True">
                                <ScrollViewer x:Name="PART_ContentHost" Margin="0,0,0,0" VerticalAlignment="Center" />
                            </Border>
                            <Label x:Uid="UsernameText" x:Name="WaterMarkLabel" Content="Only Numeric"
                               Visibility="Collapsed" Foreground="#1a1a1a" FontSize="10" Opacity="0.5"
                                   FontStyle="Italic"/>
                        </Grid>
                        <ControlTemplate.Triggers>
                            <MultiTrigger>
                                <MultiTrigger.Conditions>
                                    <Condition Property="Text" Value=""/>
                                </MultiTrigger.Conditions>
                                <Setter Property="Visibility" TargetName="WaterMarkLabel" Value="Visible"/>
                            </MultiTrigger>
                            <Trigger Property="IsEnabled" Value="False">
                                <Setter Property="Foreground" Value="DimGray"/>
                            </Trigger>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>

Posted 7-Jan-18 18:53pm

Member 11859517

Updated 8-Jan-18 0:11am

v2

Add a Solution

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Graeme_Grant · Answer 1 · 2018-01-08T00:06:00

Here is a working version of what you are trying to do:

XML

<Window x:Class="MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

        Title="Watermark Textbox demo" Height="350" Width="525">

    <Window.Resources>

        <SolidColorBrush x:Key="TextBox.Static.Border" Color="#FFABAdB3"/>
        <SolidColorBrush x:Key="TextBox.MouseOver.Border" Color="#FF7EB4EA"/>
        <SolidColorBrush x:Key="TextBox.Focus.Border" Color="#FF569DE5"/>

        <Style x:Key="CommandTextBoxStyle" TargetType="{x:Type TextBox}">
            <Setter Property="Background"
                    Value="{DynamicResource {x:Static SystemColors.WindowBrushKey}}"/>
            <Setter Property="BorderBrush"
                    Value="{StaticResource TextBox.Static.Border}"/>
            <Setter Property="Foreground"
                    Value="{DynamicResource {x:Static
                                                 SystemColors.ControlTextBrushKey}}"/>
            <Setter Property="BorderThickness" Value="1"/>
            <Setter Property="KeyboardNavigation.TabNavigation" Value="None"/>
            <Setter Property="HorizontalContentAlignment" Value="Left"/>
            <Setter Property="FocusVisualStyle" Value="{x:Null}"/>
            <Setter Property="AllowDrop" Value="true"/>
            <Setter Property="ScrollViewer.PanningMode" Value="VerticalFirst"/>
            <Setter Property="Stylus.IsFlicksEnabled" Value="False"/>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type TextBox}">
                        <Border x:Name="border"
                                BorderBrush="{TemplateBinding BorderBrush}"
                                BorderThickness="{TemplateBinding BorderThickness}"
                                Background="{TemplateBinding Background}"
                                SnapsToDevicePixels="True">
                            <Grid>
                                <ScrollViewer x:Name="PART_ContentHost"
                                              Focusable="false"
                                              HorizontalScrollBarVisibility="Hidden"
                                              VerticalScrollBarVisibility="Hidden"/>

                                <TextBlock IsHitTestVisible="False"
                                           Margin="{TemplateBinding Padding}"
                                           Text="Watermark text goes here"
                                           TextTrimming="CharacterEllipsis"
                                           FontStyle="Italic" Foreground="LightGray"
                                           DataContext="{Binding RelativeSource=
                                               {RelativeSource Mode=FindAncestor,
                                                               AncestorType=TextBox}}">
                                    <TextBlock.Style>
                                        <Style TargetType="{x:Type TextBlock}">
                                            <Setter Property="Visibility" 
                                                    Value="Collapsed"/>
                                            <Style.Triggers>
                                                <MultiDataTrigger>
                                                    <MultiDataTrigger.Conditions>
                                                        <Condition Binding="{Binding 
                                                                   Text}" Value=""/>
                                                        <Condition Binding="{Binding 
                                                                   IsKeyboardFocused}"
                                                                   Value="False"/>
                                                    </MultiDataTrigger.Conditions>
                                                    <MultiDataTrigger.Setters>
                                                        <Setter Property="Visibility" 
                                                                Value="Visible"/>
                                                    </MultiDataTrigger.Setters>
                                                </MultiDataTrigger>
                                            </Style.Triggers>
                                        </Style>
                                    </TextBlock.Style>
                                </TextBlock>

                            </Grid>
                        </Border>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
            <Style.Triggers>
                <MultiTrigger>
                    <MultiTrigger.Conditions>
                        <Condition Property="IsInactiveSelectionHighlightEnabled" 
                                   Value="true"/>
                        <Condition Property="IsSelectionActive" Value="false"/>
                    </MultiTrigger.Conditions>
                    <Setter Property="SelectionBrush"
                            Value="{DynamicResource {x:Static 
                                  SystemColors.InactiveSelectionHighlightBrushKey}}"/>
                </MultiTrigger>
            </Style.Triggers>
        </Style>

    </Window.Resources>

    <Grid HorizontalAlignment="Center">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="Auto"/>
            <ColumnDefinition Width="Auto"/>
        </Grid.ColumnDefinitions>
        <TextBox Width="200" VerticalAlignment="Center" Padding="4"
                 Style="{DynamicResource CommandTextBoxStyle}"/>
        <Button Content="Search"
                Margin="10 0" Padding="10 5"
                Grid.Column="1" VerticalAlignment="Center"/>
    </Grid>

</Window>

Alex Schunk · Answer 2 · 2018-01-08T00:11:00

Solution 2

If its in ControlTemplate it would be a messy thing to do... I would not recomend that. You would have to find that specific control in the applied template and that would cost you a lot.
Use bindings or behaviours instead...

And second... Don't use Labels, use TextBlocks.

Posted 8-Jan-18 0:11am

Alex Schunk

Comments

Graeme_Grant 8-Jan-18 6:17am

Agreed wholly. He would require a working example for this solution to help any.

However, personally, I would inherit the textbox and create a Watermark lookless control class. This however is outside the scope of this Q&A.