How to: Set the Height Properties of an Element

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.NET Framework 4 Beta 2
Windows Presentation Foundation
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Control Library
Panel
Panel How-to Topics

How to: Apply a LayoutTransform to an Element
How to: Change the Margin Property
How to: Change the Visibility Property
How to: Create a Custom Panel Element
How to: Find the Index of an Element
How to: Override the Panel OnRender Method
How to: Remove an Element by Using an Index
How to: Remove the Child Nodes of an Element

How to: Set the Width Properties of an Element

How to: Set the Height Properties of an Element
This page is specific to:.NET Framework Version:3.0 3.54.0

.NET Framework 4 - Windows Presentation Foundation

How to: Set the Height Properties of an Element

[This documentation is for preview only, and is subject to change in later releases. Blank topics are included as placeholders.]

Example

This example visually shows the differences in rendering behavior among the four height-related properties in Windows Presentation Foundation (WPF).

The FrameworkElement class exposes four properties that describe the height characteristics of an element. These four properties can conflict, and when they do, the value that takes precedence is determined as follows: the MinHeight value takes precedence over the MaxHeight value, which in turn takes precedence over the Height value. A fourth property, ActualHeight, is read-only, and reports the actual height as determined by interactions with the layout process.

The following Extensible Application Markup Language (XAML) examples draw a Rectangle element (rect1) as a child of Canvas. You can change the height properties of a Rectangle by using a series of ListBox elements that represent the property values of MinHeight, MaxHeight, and Height. In this manner, the precedence of each property is visually displayed.

XAML

<Canvas Height="200" MinWidth="200" Background="#b0c4de" VerticalAlignment="Top"  HorizontalAlignment="Center" Name="myCanvas" Margin="0,0,0,50">
    <Rectangle HorizontalAlignment="Center" Canvas.Top="50" Canvas.Left="50"  Name="rect1" Fill="#4682b4" Height="100" Width="100"/>
</Canvas>


...


    <TextBlock Grid.Row="1" Grid.Column="0" Margin="10,0,0,0" TextWrapping="Wrap">Set the Rectangle Height:</TextBlock>
    <ListBox Grid.Column="1" Grid.Row="1" Margin="10,0,0,0" Height="50" Width="50" SelectionChanged="changeHeight">
      <ListBoxItem>25</ListBoxItem>
      <ListBoxItem>50</ListBoxItem>
      <ListBoxItem>75</ListBoxItem>
      <ListBoxItem>100</ListBoxItem>
      <ListBoxItem>125</ListBoxItem>
      <ListBoxItem>150</ListBoxItem>
      <ListBoxItem>175</ListBoxItem>
      <ListBoxItem>200</ListBoxItem>
    </ListBox>

    <TextBlock Grid.Row="1" Grid.Column="2" Margin="10,0,0,0" TextWrapping="Wrap">Set the Rectangle MinHeight:</TextBlock>
    <ListBox Grid.Column="3" Grid.Row="1" Margin="10,0,0,0" Height="50" Width="50" SelectionChanged="changeMinHeight">
      <ListBoxItem>25</ListBoxItem>
      <ListBoxItem>50</ListBoxItem>
      <ListBoxItem>75</ListBoxItem>
      <ListBoxItem>100</ListBoxItem>
      <ListBoxItem>125</ListBoxItem>
      <ListBoxItem>150</ListBoxItem>
      <ListBoxItem>175</ListBoxItem>
      <ListBoxItem>200</ListBoxItem>
  </ListBox>      

    <TextBlock Grid.Row="1" Grid.Column="4" Margin="10,0,0,0" TextWrapping="Wrap">Set the Rectangle MaxHeight:</TextBlock>
    <ListBox Grid.Column="5" Grid.Row="1" Margin="10,0,0,0" Height="50" Width="50" SelectionChanged="changeMaxHeight">
      <ListBoxItem>25</ListBoxItem>
      <ListBoxItem>50</ListBoxItem>
      <ListBoxItem>75</ListBoxItem>
      <ListBoxItem>100</ListBoxItem>
      <ListBoxItem>125</ListBoxItem>
      <ListBoxItem>150</ListBoxItem>
      <ListBoxItem>175</ListBoxItem>
      <ListBoxItem>200</ListBoxItem> 
    </ListBox>

The following code-behind examples handle the events that the SelectionChanged event raises. Each handler takes the input from the ListBox, parses the value as a Double, and applies the value to the specified height-related property. The height values are also converted to a string and written to various TextBlock elements (definition of those elements is not shown in the selected XAML).

C++

JScript

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Private Sub changeHeight(ByVal sender As Object, ByVal args As SelectionChangedEventArgs)
    Dim li As ListBoxItem = CType(CType(sender, ListBox).SelectedItem, ListBoxItem)
    Dim sz1 As Double = Double.Parse(li.Content.ToString())
    rect1.Height = sz1
    rect1.UpdateLayout()
    txt1.Text = "ActualHeight is set to " + rect1.ActualHeight.ToString
    txt2.Text = "Height is set to " + rect1.Height.ToString
    txt3.Text = "MinHeight is set to " + rect1.MinHeight.ToString
    txt4.Text = "MaxHeight is set to " + rect1.MaxHeight.ToString
End Sub
Private Sub changeMinHeight(ByVal sender As Object, ByVal args As SelectionChangedEventArgs)

    Dim li As ListBoxItem = CType(CType(sender, ListBox).SelectedItem, ListBoxItem)
    Dim sz1 As Double = Double.Parse(li.Content.ToString())
    rect1.MinHeight = sz1
    rect1.UpdateLayout()
    txt1.Text = "ActualHeight is set to " + rect1.ActualHeight.ToString
    txt2.Text = "Height is set to " + rect1.Height.ToString
    txt3.Text = "MinHeight is set to " + rect1.MinHeight.ToString
    txt4.Text = "MaxHeight is set to " + rect1.MaxHeight.ToString
End Sub
Private Sub changeMaxHeight(ByVal sender As Object, ByVal args As SelectionChangedEventArgs)

    Dim li As ListBoxItem = CType(CType(sender, ListBox).SelectedItem, ListBoxItem)
    Dim sz1 As Double = Double.Parse(li.Content.ToString())
    rect1.MaxHeight = sz1
    rect1.UpdateLayout()
    txt1.Text = "ActualHeight is set to " + rect1.ActualHeight.ToString
    txt2.Text = "Height is set to " + rect1.Height.ToString
    txt3.Text = "MinHeight is set to " + rect1.MinHeight.ToString
    txt4.Text = "MaxHeight is set to " + rect1.MaxHeight.ToString
End Sub

For the complete sample, see Height Properties Sample.

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