Creating Simple Charts in WPF with PowerShell

Windows Presentation Foundation (WPF) is great for creating GUI applications, but it does not natively contain any charting controls.  There are a number of products that can be used to create charts in WPF, including the WPF toolkit and the Microsoft Chart Controls for .Net, but good-old Windows Forms does this natively.

WPF has does have a WindowsFormsHost control, but there are a number of potential issues with hosting Windows Forms in a WPF application, and it not recommended practice.

After some playing around however, I found it is possible to add a Windows Forms chart simply by displaying it as an image.  Furthermore, it is also possible to save the image to a memory stream in binary format, which means it does not need to be saved to disk as a file, but can simply be stored and read from memory in binary form.

Below is a simple example of a Windows Forms pie chart added as an image to a WPF window using PowerShell.  It calculates the used and available RAM in the local system, creates a pie chart from the data, saves it as in image in binary form, then adds it as the source to an image control in the WPF window.  Pretty cool 🙂

chart


# Add required assemblies
Add-Type -AssemblyName PresentationFramework,System.Windows.Forms,System.Windows.Forms.DataVisualization

# Create WPF window
[xml]$xaml = @"
<Window          xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"         Title="Chart Example" Height="350" Width="420">
    <Grid>
        <Image x:Name="image" HorizontalAlignment="Left" Height="auto" VerticalAlignment="Top" Width="auto"/>
    </Grid>
</Window>

"@

# Add window and it's named elements to a hash table
$script:hash = @{}
$hash.Window = [Windows.Markup.XamlReader]::Load((New-Object -TypeName System.Xml.XmlNodeReader -ArgumentList $xaml))
$xaml.SelectNodes("//*[@*[contains(translate(name(.),'n','N'),'Name')]]") | ForEach-Object -Process {
    $hash.$($_.Name) = $hash.Window.FindName($_.Name)
}

# Function to create a Windows Forms pie chart
# Modified from https://www.simple-talk.com/sysadmin/powershell/building-a-daily-systems-report-email-with-powershell/
Function Create-PieChart() {
    param([hashtable]$Params)

    #Create our chart object
    $Chart = New-object System.Windows.Forms.DataVisualization.Charting.Chart
    $Chart.Width = 430
    $Chart.Height = 330
    $Chart.Left = 10
    $Chart.Top = 10

    #Create a chartarea to draw on and add this to the chart
    $ChartArea = New-Object System.Windows.Forms.DataVisualization.Charting.ChartArea
    $Chart.ChartAreas.Add($ChartArea)
    [void]$Chart.Series.Add("Data") 

    #Add a datapoint for each value specified in the parameter hash table
    $Params.GetEnumerator() | foreach {
        $datapoint = new-object System.Windows.Forms.DataVisualization.Charting.DataPoint(0, $_.Value.Value)
        $datapoint.AxisLabel = "$($_.Value.Header)" + "(" + $($_.Value.Value) + " GB)"
        $Chart.Series["Data"].Points.Add($datapoint)
    }

    $Chart.Series["Data"].ChartType = [System.Windows.Forms.DataVisualization.Charting.SeriesChartType]::Pie
    $Chart.Series["Data"]["PieLabelStyle"] = "Outside"
    $Chart.Series["Data"]["PieLineColor"] = "Black"
    $Chart.Series["Data"]["PieDrawingStyle"] = "Concave"
    ($Chart.Series["Data"].Points.FindMaxByValue())["Exploded"] = $true

    #Set the title of the Chart
    $Title = new-object System.Windows.Forms.DataVisualization.Charting.Title
    $Chart.Titles.Add($Title)
    $Chart.Titles[0].Text = "RAM Usage Chart ($($env:COMPUTERNAME))"

    #Save the chart to a memory stream, then to the hash table as a byte array
    $Stream = New-Object System.IO.MemoryStream
    $Chart.SaveImage($Stream,"png")
    $Hash.Stream = $Stream.GetBuffer()
    $Stream.Dispose()
}

# Add an event to display the chart when the window is opened
$hash.Window.Add_ContentRendered({
    # Create a hash table to store values
    $Params = @{}
    # Get local RAM usage from WMI
    $RAM = (Get-CimInstance -ClassName Win32_OperatingSystem -Property TotalVisibleMemorySize,FreePhysicalMemory)
    # Add Free RAM to a hash table
    $Params.FreeRam = @{}
    $Params.FreeRam.Header = "Free RAM"
    $Params.FreeRam.Value = [math]::Round(($RAM.FreePhysicalMemory / 1MB),2)
    # Add used RAM to a hash table
    $Params.UsedRam = @{}
    $Params.UsedRam.Header = "Used RAM"
    $Params.UsedRam.Value = [math]::Round((($RAM.TotalVisibleMemorySize / 1MB) - ($RAM.FreePhysicalMemory / 1MB)),2)
    # Create the Chart
    Create-PieChart $Params
    # Set the image source
    $Hash.image.Source = $hash.Stream
})

# Display window
$null = $hash.Window.ShowDialog()

New Tool: System Explorer for Windows

Today I am pleased to release a new tool for enterprises and home users alike: System Explorer for Windows.  This application can be used to view detailed system and hardware data for a local or remote computer by exposing WMI Win32 classes in an easy-to-use Graphical User Interface.  For enterprises that use System Center Configuration Manager, the application can connect to the SCCM database to allow viewing of hardware inventory data even if the target system is not currently online.

capture
System Explorer for Windows – Client WMI view

Check it out here: https://smsagent.wordpress.com/tools/system-explorer-for-windows/