WPF Grid in Powershell get cutted in height - wpf

Question

I want to draw some information's with Powershell on a background image. I use a WPF Form to write those informations, for better formatting/styleing. Problem is, that the DataGrid get cut in height, when I have to mush information's, which I not understand. I tryd with MaxHeight and different other propertys, but could not fix it.
Add-Type -AssemblyName PresentationFramework, System.Drawing
[void][System.Reflection.Assembly]::LoadWithPartialName('PresentationFramework')
[xml]$xaml = #'
<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:WpfApp1" SizeToContent="WidthAndHeight"
Name="window" Height="Auto" Width="Auto" Background="Blue" WindowStyle="ToolWindow">
<Window.Resources>
<Style TargetType="Grid">
<Setter Property="ShowGridLines" Value="True"/>
<Setter Property="Background" Value="Transparent"/>
<Setter Property="Width" Value="Auto"/>
<Setter Property="Height" Value="Auto"/>
</Style>
<Style TargetType="TableCell">
<Setter Property="LineHeight" Value="Auto"/>
<Setter Property="BorderThickness" Value="1"/>
</Style>
<Style TargetType="RowDefinition" >
<Setter Property="Height" Value="Auto"/>
</Style>
<Style TargetType="TableColumn">
<Setter Property="Width" Value="Auto"/>
</Style>
<Style TargetType="TextBlock" >
<Setter Property="FontFamily" Value="Consolas" />
<Setter Property="FontSize" Value="20" />
<Setter Property="Foreground" Value="White" />
<Setter Property="Margin" Value="0" />
<Setter Property="Padding" Value="0" />
</Style>
<Style TargetType="DataGrid">
<Setter Property="Background" Value="Transparent"/>
<Setter Property="GridLinesVisibility" Value="All"/>
<Setter Property="HeadersVisibility" Value="None"/>
</Style>
<Style TargetType="DataGridRow">
<Setter Property="Background" Value="Transparent"/>
<Setter Property="Height" Value="Auto"/>
</Style>
<Style TargetType="DataGridCell">
<Setter Property="Height" Value="Auto"/>
<Setter Property="Foreground" Value="White" />
<Setter Property="FocusVisualStyle" Value="{x:Null}" />
<Setter Property="BorderThickness" Value="0"/>
<Setter Property="FontFamily" Value="Consolas" />
<Setter Property="FontSize" Value="20" />
</Style>
</Window.Resources>
<Grid Name="Grid1" >
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition/>
<RowDefinition/>
</Grid.RowDefinitions>
<TextBlock Grid.Row="0" Grid.Column="0" Padding="0,0,0,20" FontSize="30"><TextBlock FontSize="30" Foreground="#FFCBCBCB">This</TextBlock> is my Header!</TextBlock>
<DataGrid Grid.Row="1" Grid.Column="0" Name="DG1" AutoGenerateColumns="False">
<DataGrid.Columns>
<DataGridTextColumn Header="Name" Binding="{Binding Name}" Width="Auto" CanUserResize="False" CanUserReorder="False" />
<DataGridTextColumn Header="Spacer" Binding="{Binding Spacer}" Width="50" CanUserResize="False" CanUserReorder="False" />
<DataGridTextColumn Header="Value" Binding="{Binding Value}" Width="Auto" CanUserResize="False" CanUserReorder="False" />
</DataGrid.Columns>
</DataGrid>
<TextBlock Grid.Row="2" Grid.Column="0" Padding="0,50,0,0">This is my Footer</TextBlock>
</Grid>
</Window>
'#
# Read XAML
$reader=(New-Object System.Xml.XmlNodeReader $xaml)
try{
$WpfApp1=[Windows.Markup.XamlReader]::Load( $reader )
}
catch{
Write-Error "Unable to parse XML, with error: $($Error[0])`n Ensure that there are NO SelectionChanged or TextChanged properties (PowerShell cannot process them)"
throw
}
# Store Form Objects In PowerShell
$xaml.SelectNodes("//*[#Name]") | %{"trying item $($_.Name)";
try {Set-Variable -Name "WPF_$($_.Name)" -Value $WpfApp1.FindName($_.Name) -ErrorAction Stop}
catch{throw}
}
# Fülle Grid
for ($i=1; $i -le 60; $i++) {
$WPF_DG1.AddChild([pscustomobject]#{Name='Test';Value=$i})
}
$WPF_window.AllowsTransparency = $True
$WPF_window.Opacity = 0
$WPF_window.ShowInTaskbar = $False
$WPF_window.ShowActivated = $False
$WPF_window.WindowStyle = 'None'
$WpfApp1.Add_ContentRendered({
$WpfApp1.Close()
})
$WpfApp1.ShowDialog() | out-null
[int]$infoHeight = $WPF_Grid1.ActualHeight
[int]$infoWidth = $WPF_Grid1.ActualWidth
[string]::Format("WPF_Grid1 Größe: {0}x{1}", $infoWidth, $infoHeight) | Write-Host
# Speichere WPF-Grid in Bitmap
$rBmp = New-Object Windows.Media.Imaging.RenderTargetBitmap($infoWidth, $infoHeight, 96, 96, ([Windows.Media.PixelFormats]::Pbgra32))
$rBmp.Render($WPF_Grid1)
# Konvertiere Bitmap
$ms = New-Object System.IO.MemoryStream
$enc = New-Object System.Windows.Media.Imaging.BmpBitmapEncoder
$enc.Frames.Add([Windows.Media.Imaging.BitmapFrame]::Create($rBmp))
$enc.Save($ms)
$infoImg = [System.Drawing.Image]::FromStream($ms)
$infoImg.MakeTransparent()
[string]::Format("infoImg Größe: {0}x{1}", $infoImg.width, $infoImg.height) | Write-Host
# Lese Quell-Bild
$srcImg = [System.Drawing.Image]::FromFile($Env:WinDir + "\Web\Screen\img100.jpg")
[string]::Format("srcImg Größe: {0}x{1}", $srcImg.width, $srcImg.height) | Write-Host
# Erstelle ein Bitmap in das gezeichnet wird
$dstBmp = New-Object System.Drawing.Bitmap(([int]($srcImg.width)),([int]($srcImg.height)))
# Erstelle Graphics Objekt
$gUnit = [Drawing.GraphicsUnit]::Pixel
$gImg = [System.Drawing.Graphics]::FromImage($dstBmp)
$gImg.CompositingQuality = [System.Drawing.Drawing2D.CompositingQuality]::HighQuality
$gImg.SmoothingMode = [System.Drawing.Drawing2D.SmoothingMode]::AntiAlias
$gImg.InterpolationMode = [System.Drawing.Drawing2D.InterpolationMode]::HighQualityBicubic
$gImg.PixelOffsetMode = [System.Drawing.Drawing2D.PixelOffsetMode]::HighQuality
# Zeichne das Quell-Bild in unser gImg
$srcRect = New-Object Drawing.Rectangle(0, 0, $srcImg.Width, $srcImg.Height)
$gImg.DrawImage($srcImg, $srcRect, 0, 0, $srcImg.Width, $srcImg.Height, $gUnit)
# get scale ratio
$xpos = 150
$ypos = 150
$ratio = 0.1
while($($infoImg.Height*$ratio) -le $(($srcImg.Height-$ypos)*0.75))
{
$ratio += 0.1
#[string]::Format("if ({0} -le {1})", $($infoImg.Height*$ratio), $($srcImg.Height*0.75)) | Write-Host
}
[string]::Format("infoRect: X={0} Y={1} RATIO={2}", $xpos, $ypos, $ratio) | Write-Host
# Zeichne das Info-Bild in unser gImg
$infoRect = New-Object Drawing.Rectangle($xpos, $ypos, $($infoImg.Width*$ratio), $($infoImg.Height*$ratio))
$gImg.DrawImage($infoImg, $infoRect, 0, 0, $infoImg.Width, $infoImg.Height, $gUnit)
# Aufräumen
Remove-Item –Path "$($Env:Temp)\Test-*.jpg" -Force
# Neue Ausgabedatei erstellen
$dstFile = "$($Env:Temp)\Test-$(get-date -Format yyyy-MM-dd-HH-mm).jpg"
$dstBmp.save($dstFile, [System.Drawing.Imaging.ImageFormat]::Jpeg)
I added a full working test code (on win 10 - because of the background image, you can change also to other image), which shows the problem.
Check the resulting Test-*.jpg in %Temp% - we should see, the footer of the grid. When we change the for loop to max 30 the whole thing is working... but I need to display sometimes more informations.
Hope someone can point out what causes the problem. Found nothing identical on the net and was working on it for hours....

Answer 1

In WPF, when your app is rendered, the actual height is set to a maximum of the bounds of your monitor. It make sense, since in normal time you wouldn't want a window bigger than your monitor.
The snapshot you take of your window take only in consideration the rendered part, which is leaving out some elements in your case.
To circumvent this, you want to let the window go as big as it want.
Since you don't know the height of the window, what you can do here is to set an arbitrary MinHeight value to make sure your window encompass everything.
Since it won't be displayed on screen and we don't care if the window is out of bounds, we'll use 3000 here.
From there, we'll use your Add-ContentRendered scriptblock and calculate the actual height of our Grid (Header + Datagrid + Footer).
We'll then reset the MinHeight and Height attribute of our window to that size, so our snapshot does not include the empty space.
Here's the affected part of your code and what it looks with the modification
# Arbitrary value to make sure all of our content will be captured
$WPF_window.MinHeight = 3000
$WpfApp1.Add_ContentRendered( {
$MinHeight = ($WPF_Grid1.RowDefinitions.ActualHeight | Measure-Object -Sum) |
Select -ExpandProperty Sum
$WPF_window.MinHeight = $MinHeight
$WPF_window.Height = $MinHeight
$WpfApp1.Close()
})