How do I prevent a textbox's width from growing outside its container?

Question

I want to allow a textbox to grow in size, until it fills its container. If you place a blank textbox on a WPF window, it will increase in size (as a user types text into it) until it fills the container, at which point it will stop expanding in size.

However, if I place that textbox in a grid, the textbox never ceases to grow. And even stranger, if I hardcode some fixed widths on the grid's columns, the textbox will even STILL continue to grow.

I want the textbox to grow, and the grid to grow, but once the grid cannot grow anymore, I want the textbox to stop growing also. Can this be done?

---

Here's a quick sample. As you type into the textbox, it'll grow in size (as intended). However, the textbox will continue to grow even after the grid is completely filled the WPF form.

<Window x:Class="WpfApplication1.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525" Name="window">
<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="Auto" />
        <ColumnDefinition Width="Auto" />
    </Grid.ColumnDefinitions>
    <TextBlock Grid.Column="0" Text="StackOverflow"/>
    <TextBox Grid.Column="1"/>
</Grid>
</Window>

Answer 1

Setting the second column definition's width to "*" should provide you with the desired functionality.

In addition, set the MinWidth on the textbox, and the HorizontalAlignment to Left, so that it doesn't stretch to the column width. If you want it to stretch, then remove this property.

In this example, I added an additional column with a width of 50 to highlight that the textbox will stop growing once it meets the column width boundary.

<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="Auto" />
        <ColumnDefinition Width="*" />
        <ColumnDefinition Width="50" />    
    </Grid.ColumnDefinitions>

    <TextBlock Grid.Column="0"
                Text="StackOverflow" />

    <TextBox Grid.Column="1"
                HorizontalAlignment="Left"
                MinWidth="50" />
</Grid>