网格上的左水平对齐

Question

I'm trying to use HorizontalAlignment="Left" in the following situation:

<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
  <Grid HorizontalAlignment="Left">
    <Grid.ColumnDefinitions>
      <ColumnDefinition />
      <ColumnDefinition />
      <ColumnDefinition />
    </Grid.ColumnDefinitions>
    <TextBlock Grid.Column="0" Background="Gray" Text="Small Text"  TextWrapping="Wrap"/>
    <TextBlock Grid.Column="1" Background="White" Text="This is a very large amount of text"  TextWrapping="Wrap"/>
    <TextBlock Grid.Column="2" Background="Gray" Text="Medium amount of text" TextWrapping="Wrap"/>
  </Grid>
</Window>

My goal is to be able to resize the window, and have the three TextBlocks resize themselves proportionally. This works, but the grid is putting some blank space to the right of the final column, and as I try to resize towards the final column, the columns start to shrink. I want this shrinking behavior, but I don't want it to start until there is no more white space to the right of the rightmost column.

I can't use a UniformGrid as the text lengths can vary, and no other built-in WPF control that I've seen has the ability to resize all children when the parent size changes. I've looked into creating a custom panel, but that seems to be more trouble than it's worth. I feel like something much more simple can be done here.

Any suggestions or ideas are appreciated.

Answer 1

You'll have to build your own custom panel, and handle the case where the AvailableWidth is less then the panel's children DesiredWidth

Panel layout in WPF (Grid is a Panel) is a 2 step process, in the first pass the Panel iterates over its children and provides them with the panel's AvailableWidth . The children respond to this by computing their DesiredWidth .

In the second pass the Panel arranges the children according to their DesiredWidth . In this second pass you have access to the width that all the children (in your case, TextBlocks) require. If it is less than the panel's available width you can compute a percentage to give each one so that they appear to shrink uniformly.

Here's a resource that shows how you can create your own custom panel

Answer 2

What about this?

<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="1*"/>
        <ColumnDefinition Width="1*"/>
        <ColumnDefinition Width="1*"/>
</Grid.ColumnDefinitions>