HorizontalAlignment=Stretch, MaxWidth, and Left aligned at the same time?

Question

This seems like it should be easy but I'm stumped. In WPF, I'd like a TextBox that stretches to the width of it's parent, but only to a maximum width. The problem is that I want it to be left justified within its parent. To get it to stretch you have to use HorizontalAlignment="Stretch", but then the result is centered. I've experimented with HorizontalContentAlignment, but it doesn't seem to do anything.

How do I get this blue text box to grow with the size of the window, have a maximum width of 200 pixels, and be left justified?

<Page
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
  <StackPanel>  
    <TextBox Background="Azure" Text="Hello" HorizontalAlignment="Stretch" MaxWidth="200" />
  </StackPanel>
</Page>

What's the trick?

score 96 · Accepted Answer · edited Oct 26 '13 at 21:38

96

You can set HorizontalAlignment to Left, set your MaxWidth and then bind Width to the ActualWidth of the parent element:

<Page
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
  <StackPanel Name="Container">   
    <TextBox Background="Azure" 
    Width="{Binding ElementName=Container,Path=ActualWidth}"
    Text="Hello" HorizontalAlignment="Left" MaxWidth="200" />
  </StackPanel>
</Page>

edited Oct 26 '13 at 21:38

Dave Clemmer

3,741
12
49
72

answered Nov 11 '08 at 09:25

Nir

29,306
10
67
103

9

Doesn't autoresize.. Seems to be fit to content.. am I missing something? – Gishu Nov 11 '08 at 09:46
This seems to crash my silverlight player – resopollution Jun 02 '09 at 23:35
4

@Gishu, make sure you set `HorizontalAlignment="Stretch"` on the `Container ` element. (p.s., I do realize you asked that question over 6 years ago.) – David Murdoch Mar 02 '15 at 23:35

score 55 · Answer 2 · edited Sep 28 '11 at 01:05

55

<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="*" MaxWidth="200"/>
    </Grid.ColumnDefinitions>

    <TextBox Background="Azure" Text="Hello" />
</Grid>

edited Sep 28 '11 at 01:05

answered Nov 11 '08 at 09:13

Kent Boogaart

175,602
35
392
393

I think you need to set VerticalAlignment="Top" for the textbox.. seems to be stretch by default. – Gishu Nov 11 '08 at 09:39
1

+1. Nice and clean. Anytime I try to manage layout by binding to some actual width (as in the accepted answer), things get messy. – Eren Ersönmez Aug 14 '14 at 05:55
1

I just came across this question whilst trying to solve the same problem. In my case this is the best answer as it works in WinRT. The other answer doesn't because you cannot bind on ActualWidth in WinRT. – Slade Oct 24 '15 at 22:24
Slade - I just did this in a Windows Store app: MaxWidth="{Binding ActualWidth, ElementName=Layout}" and it worked fine for binding MaxWidth to another elements ActualWidth property. I'm not sure why this worked for me but it did what I expected, and like was mentioned earlier in the answer that had the Width binding solution, it didn't resize the element when the parent resized due to making the window bigger or smaller. – David Rector Apr 30 '16 at 09:59
This works only for the last column. I you have more columns behind the `MaxWidth`'s column, the will be pulled to the left as well. – jor Feb 09 '21 at 13:02

score 8 · Answer 3 · answered Nov 11 '08 at 11:26

Both answers given worked for the problem I stated -- Thanks!

In my real application though, I was trying to constrain a panel inside of a ScrollViewer and Kent's method didn't handle that very well for some reason I didn't bother to track down. Basically the controls could expand beyond the MaxWidth setting and defeated my intent.

Nir's technique worked well and didn't have the problem with the ScrollViewer, though there is one minor thing to watch out for. You want to be sure the right and left margins on the TextBox are set to 0 or they'll get in the way. I also changed the binding to use ViewportWidth instead of ActualWidth to avoid issues when the vertical scrollbar appeared.

score 7 · Answer 4 · answered Aug 26 '10 at 08:25

You can use this for the Width of your DataTemplate:

Width="{Binding ActualWidth,RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ScrollContentPresenter}}}"

Make sure your DataTemplate root has Margin="0" (you can use some panel as the root and set the Margin to the children of that root)

Y C · Answer 5 · 2022-03-30T05:45:24.583

Maybe I can still help somebody out who bumps into this question, because this is a very old issue.

I needed this as well and wrote a behavior to take care of this. So here is the behavior:

public class StretchMaxWidthBehavior : Behavior<FrameworkElement>
{        
    protected override void OnAttached()
    {
        base.OnAttached();
        ((FrameworkElement)this.AssociatedObject.Parent).SizeChanged += this.OnSizeChanged;
    }

    protected override void OnDetaching()
    {
        base.OnDetaching();
        ((FrameworkElement)this.AssociatedObject.Parent).SizeChanged -= this.OnSizeChanged;
    }

    private void OnSizeChanged(object sender, SizeChangedEventArgs e)
    {
        this.SetAlignments();
    }

    private void SetAlignments()
    {
        var slot = LayoutInformation.GetLayoutSlot(this.AssociatedObject);
        var newWidth = slot.Width;
        var newHeight = slot.Height;

        if (!double.IsInfinity(this.AssociatedObject.MaxWidth))
        {
            if (this.AssociatedObject.MaxWidth < newWidth)
            {
                this.AssociatedObject.HorizontalAlignment = HorizontalAlignment.Left;
                this.AssociatedObject.Width = this.AssociatedObject.MaxWidth;
            }
            else
            {
                this.AssociatedObject.HorizontalAlignment = HorizontalAlignment.Stretch;
                this.AssociatedObject.Width = double.NaN;
            }
        }

        if (!double.IsInfinity(this.AssociatedObject.MaxHeight))
        {
            if (this.AssociatedObject.MaxHeight < newHeight)
            {
                this.AssociatedObject.VerticalAlignment = VerticalAlignment.Top;
                this.AssociatedObject.Height = this.AssociatedObject.MaxHeight;
            }
            else
            {
                this.AssociatedObject.VerticalAlignment = VerticalAlignment.Stretch;
                this.AssociatedObject.Height = double.NaN;
            }
        }
    }
}

Then you can use it like so:

<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="Auto" />
        <ColumnDefinition />
    </Grid.ColumnDefinitions>

    <TextBlock Grid.Column="0" Text="Label" />
    <TextBox Grid.Column="1" MaxWidth="600">
          <i:Interaction.Behaviors>                       
               <cbh:StretchMaxWidthBehavior/>
          </i:Interaction.Behaviors>
    </TextBox>
</Grid>

Note: don't forget to use the System.Windows.Interactivity namespace to use the behavior.

score 3 · Answer 6 · answered Oct 31 '19 at 10:34

Functionally similar to the accepted answer, but doesn't require the parent element to be specified:

<TextBox
    Width="{Binding ActualWidth, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type FrameworkElement}}}"
    MaxWidth="500"
    HorizontalAlignment="Left" />

score 0 · Answer 7 · edited Jan 29 '19 at 10:49

0

I would use SharedSizeGroup

<Grid>
    <Grid.ColumnDefinition>
        <ColumnDefinition SharedSizeGroup="col1"></ColumnDefinition>  
        <ColumnDefinition SharedSizeGroup="col2"></ColumnDefinition>
    </Grid.ColumnDefinition>
    <TextBox Background="Azure" Text="Hello" Grid.Column="1" MaxWidth="200" />
</Grid>

edited Jan 29 '19 at 10:49

McGuireV10

9,572
5
48
64

answered Sep 03 '17 at 19:47

Patrick Cairns

143
1
7

score 0 · Answer 8 · answered Jun 15 '20 at 15:56

In my case I had to put textbox into a stack panel in order to stretch textbox on left side. Thanks to previous post. Just for an example I did set a background color to see what’s happens when window size is changing.

<StackPanel Name="JustContainer" VerticalAlignment="Center" HorizontalAlignment="Stretch" Background="BlueViolet" >
    <TextBox 
       Name="Input" Text="Hello World" 
       MaxWidth="300"
       HorizontalAlignment="Right"
       Width="{Binding ActualWidth, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type FrameworkElement}}}">
    </TextBox>
</StackPanel>

score 0 · Answer 9 · edited Dec 04 '22 at 15:54

These answers didn't work for me, because I needed a TextBox to stretch (i.e. consume all available space) until it reaches it's MaxWidth and, if more space is available, align to the right.

I created this simple control that works along the lines of Y C's answer, but doesn't require System.Windows.Interactivity:

public class StretchAlignmentPanel : ContentControl
{
    public StretchAlignmentPanel()
    {
        this.SizeChanged += StretchAlignmentPanel_SizeChanged;
    }

    public static readonly DependencyProperty HorizontalFallbackAlignmentProperty = DependencyProperty.Register(
        nameof(HorizontalFallbackAlignment), typeof(HorizontalAlignment), typeof(StretchAlignmentPanel), new PropertyMetadata(HorizontalAlignment.Stretch));

    public HorizontalAlignment HorizontalFallbackAlignment
    {
        get { return (HorizontalAlignment)GetValue(HorizontalFallbackAlignmentProperty); }
        set { SetValue(HorizontalFallbackAlignmentProperty, value); }
    }

    public static readonly DependencyProperty VerticalFallbackAlignmentProperty = DependencyProperty.Register(
        nameof(VerticalFallbackAlignment), typeof(VerticalAlignment), typeof(StretchAlignmentPanel), new PropertyMetadata(VerticalAlignment.Stretch));

    public VerticalAlignment VerticalFallbackAlignment
    {
        get { return (VerticalAlignment)GetValue(VerticalFallbackAlignmentProperty); }
        set { SetValue(VerticalFallbackAlignmentProperty, value); }
    }

    private void StretchAlignmentPanel_SizeChanged(object sender, System.Windows.SizeChangedEventArgs e)
    {
        var fe = this.Content as FrameworkElement;
        if (fe == null) return;
        
        if(e.WidthChanged) applyHorizontalAlignment(fe);
        if(e.HeightChanged) applyVerticalAlignment(fe);
    }

    private void applyHorizontalAlignment(FrameworkElement fe)
    {
        if (HorizontalFallbackAlignment == HorizontalAlignment.Stretch) return;

        if (this.ActualWidth > fe.MaxWidth)
        {
            fe.HorizontalAlignment = HorizontalFallbackAlignment;
            fe.Width = fe.MaxWidth;
        }
        else
        {
            fe.HorizontalAlignment = HorizontalAlignment.Stretch;
            fe.Width = double.NaN;
        }
    }

    private void applyVerticalAlignment(FrameworkElement fe)
    {
        if (VerticalFallbackAlignment == VerticalAlignment.Stretch) return;

        if (this.ActualHeight > fe.MaxHeight)
        {
            fe.VerticalAlignment = VerticalFallbackAlignment;
            fe.Height= fe.MaxHeight;
        }
        else
        {
            fe.VerticalAlignment = VerticalAlignment.Stretch;
            fe.Height= double.NaN;
        }
    }
}

It can be used like this:

<controls:StretchAlignmentPanel HorizontalFallbackAlignment="Right">
    <TextBox MaxWidth="200" MinWidth="100" Text="Example"/>
</controls:StretchAlignmentPanel>

HorizontalAlignment=Stretch, MaxWidth, and Left aligned at the same time?

9 Answers9

Linked