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Parsing WinMD with .NET reflection APIs

2016 Nov 2, 6:13

Parsing WinMD files, the containers of WinRT API metadata, is relatively simple using the appropriate .NET reflection APIs. However, figuring out which reflection APIs to use is not obvious. I've got a completed C sharp class parsing WinMD files that you can check out for reference.

Use System.Reflection.Assembly.ReflectionOnlyLoad to load the WinMD file. Don't use the normal load methods because the WinMD files contain only metadata. This will load up info about APIs defined in that WinMD, but any references to types outside of that WinMD including types found in the normal OS system WinMD files must be resolved by the app code via the System.Reflection.InteropServices.WindowsRuntimeMetadata.ReflectionOnlyNamespaceResolve event.

In this event handler you must resolve the unknown namespace reference by adding an assembly to the NamespaceResolveEventArgs's ResolvedAssemblies property. If you're only interested in OS system WinMD files you can use System.Reflection.InteropServices.WindowsRuntimeMetadata.ResolveNamespace to turn a namespace into the expected OS system WinMD path and turn that path into an assembly with ReflectionOnlyLoad.

PermalinkComments.net code programming winmd winrt

JavaScript & .NET interop via WebBrowser Control

2011 Apr 5, 10:00

For my GeolocMock weekend project I intended to use the Bing Maps API to display a map in a WebBrowser control and allow the user to interact with that to select a location to be consumed by my application. Getting my .NET code to talk to the JavaScript in the WebBrowser control was surprisingly easy.

To have .NET execute JavaScript code you can use the InvokeScript method passing the name of the JavaScript function to execute and an object array of parameters to pass:

this.webBrowser2.Document.InvokeScript("onLocationStateChanged",
new object[] {
latitudeTextBoxText,
longitudeTextBoxText,
altitudeTextBoxText,
uncertaintyTextBoxText
});

The other direction, having JavaScript call into .NET is slightly more complicated but still pretty easy as far as language interop goes. The first step is to mark your assembly as ComVisible so that it can interact with JavaScript via COM. VS had already added a ComVisible declaration to my project I just had to change the value to true.

[assembly: ComVisible(true)]

Next set ObjectForScripting attribute to the object you want to expose to JavaScript.

this.webBrowser2.ObjectForScripting = this.locationState;

Now that object is exposed as window.external in JavaScript and you can call methods on it.

window.external.Set(lat, long, alt, gUncert);

However you don't seem to be able to test for the existence of methods off of it. For example the following JavaScript generates an exception for me even though I have a Set method:

if (window.external && window.external.Set) {
PermalinkCommentsjavascript webbrowser .net technical csharp

ILSpy - SharpDevelop Wiki

2011 Mar 28, 4:06"ILSpy is the open-source .NET assembly browser and decompiler. Development started after Red Gate announced that the free version of .NET Reflector would cease to exist by end of February 2011."PermalinkComments.net tools reflector c# development csharp dotnet technical tool

Tessnet2 a .NET 2.0 Open Source OCR assembly using Tesseract engine

2010 Dec 7, 12:10PermalinkCommentsopen-source opensource ocr library .net csharp programming technical

Kevin Frei @ NWCPP: Exception Handling Cost

2010 May 10, 7:23"Kevin Frei - Exception Hanlding Cost September 2006 meeting of the Northwest C++ Users Group. Discussion of the assembly language cost of exception handling on the x86 Windows and x64 Windows platform"PermalinkCommentsC++ programming language exception microsoft windows performance technical video

Flavorwire ยป Re-assembly Required: Artists on IKEA

2010 Feb 22, 7:34Art created from IKEA products.PermalinkCommentsart design ikea hack

The Old New Thing : Advantages of knowing your x86 machine code

2010 Feb 19, 2:27Raymond's tips for modifying x86 assembly code while debugging.PermalinkCommentstutorial debug debugging technical assembly x86 windows raymond-chen tips

Annotated x64 Disassembly

2010 Feb 19, 2:26A short tutorial on debugging amd64 assemblyPermalinkCommentsmicrosoft tutorial msdn debug debugging technical assembly x64 amd64 windows documentation

Annotated x86 Disassembly

2010 Feb 19, 2:25A short tutorial on debugging x86 assembly code.PermalinkCommentsmicrosoft tutorial msdn debug debugging technical assembly x86 windows documentation

PowerShell Scanning Script

2009 Jun 27, 3:42

I've hooked up the printer/scanner to the Media Center PC since I leave that on all the time anyway so we can have a networked printer. I wanted to hook up the scanner in a somewhat similar fashion but I didn't want to install HP's software (other than the drivers of course). So I've written my own script for scanning in PowerShell that does the following:

  1. Scans using the Windows Image Acquisition APIs via COM
  2. Runs OCR on the image using Microsoft Office Document Imaging via COM (which may already be on your PC if you have Office installed)
  3. Converts the image to JPEG using .NET Image APIs
  4. Stores the OCR text into the EXIF comment field using .NET Image APIs (which means Windows Search can index the image by the text in the image)
  5. Moves the image to the public share

Here's the actual code from my scan.ps1 file:

param([Switch] $ShowProgress, [switch] $OpenCompletedResult)

$filePathTemplate = "C:\users\public\pictures\scanned\scan {0} {1}.{2}";
$time = get-date -uformat "%Y-%m-%d";

[void]([reflection.assembly]::loadfile( "C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Drawing.dll"))

$deviceManager = new-object -ComObject WIA.DeviceManager
$device = $deviceManager.DeviceInfos.Item(1).Connect();

foreach ($item in $device.Items) {
        $fileIdx = 0;
        while (test-path ($filePathTemplate -f $time,$fileIdx,"*")) {
                [void](++$fileIdx);
        }

        if ($ShowProgress) { "Scanning..." }

        $image = $item.Transfer();
        $fileName = ($filePathTemplate -f $time,$fileIdx,$image.FileExtension);
        $image.SaveFile($fileName);
        clear-variable image

        if ($ShowProgress) { "Running OCR..." }

        $modiDocument = new-object -comobject modi.document;
        $modiDocument.Create($fileName);
        $modiDocument.OCR();
        if ($modiDocument.Images.Count -gt 0) {
                $ocrText = $modiDocument.Images.Item(0).Layout.Text.ToString().Trim();
                $modiDocument.Close();
                clear-variable modiDocument

                if (!($ocrText.Equals(""))) {
                        $fileAsImage = New-Object -TypeName system.drawing.bitmap -ArgumentList $fileName
                        if (!($fileName.EndsWith(".jpg") -or $fileName.EndsWith(".jpeg"))) {
                                if ($ShowProgress) { "Converting to JPEG..." }

                                $newFileName = ($filePathTemplate -f $time,$fileIdx,"jpg");
                                $fileAsImage.Save($newFileName, [System.Drawing.Imaging.ImageFormat]::Jpeg);
                                $fileAsImage.Dispose();
                                del $fileName;

                                $fileAsImage = New-Object -TypeName system.drawing.bitmap -ArgumentList $newFileName 
                                $fileName = $newFileName
                        }

                        if ($ShowProgress) { "Saving OCR Text..." }

                        $property = $fileAsImage.PropertyItems[0];
                        $property.Id = 40092;
                        $property.Type = 1;
                        $property.Value = [system.text.encoding]::Unicode.GetBytes($ocrText);
                        $property.Len = $property.Value.Count;
                        $fileAsImage.SetPropertyItem($property);
                        $fileAsImage.Save(($fileName + ".new"));
                        $fileAsImage.Dispose();
                        del $fileName;
                        ren ($fileName + ".new") $fileName
                }
        }
        else {
                $modiDocument.Close();
                clear-variable modiDocument
        }

        if ($ShowProgress) { "Done." }

        if ($OpenCompletedResult) {
                . $fileName;
        }
        else {
                $result = dir $fileName;
                $result | add-member -membertype noteproperty -name OCRText -value $ocrText
                $result
        }
}

I ran into a few issues:

PermalinkCommentstechnical scanner ocr .net modi powershell office wia

The Old New Thing : The history of calling conventions, part 5: amd64

2009 Apr 1, 6:19"The first four parameters to a function are passed in rcx, rdx, r8 and r9. Any further parameters are pushed on the stack. Furthermore, space for the register parameters is reserved on the stack, in case the called function wants to spill them; this is important if the function is variadic."PermalinkCommentsamd64 calling-convention debug x64 msdn raymond-chen assembly

Intel Assembly Quick Reference

2006 Aug 31, 7:25Debugging assembly isn't that bad... Although source+symbols is much nicer.PermalinkCommentsintel x86 assembly programming reference
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