Re: Accessing unmanaged class from C# - C# Discussion Boards

Accessing unmanaged class from C#

29-Mar-16 4:25

Hira Khalid wrote:
The value of R is (237,19,119)

Really, in a single byte?

Re: working with pixels

harold aptroot29-Mar-16 9:34

harold aptroot

29-Mar-16 9:34

There is only one part of this question that makes sense, which is that every pixel has R, G and B, all bytes, which is very likely since that's the most common type of pixel these days. The rest may make sense in some parallel universe but not in this one.

Leif Simon Goodwin29-Mar-16 1:22

29-Mar-16 1:22

I have a DLL which exports two methods, getSc and releasesSc. The first returns a handle which is a pointer to a class instance. I wish to call the methods on that class instance. Unfortunately that class is not exported as dumpbin proves:

1 0 00001040 ??4CSmartCard@XXXXXDLLNamespace@@QAEAAV01@ABV01@@Z
2 1 00003E40 _getSc@0
3 2 00003E70 _releaseSc@0
4 3 00003E40 getSc
5 4 00003E70 releaseSc

Is there a neat way to call the method on that class instance from C#/.Net?

The only way I can think of is to create an unmanaged DLL which wraps the other DLL. Thus the second DLL would expose functions to call into the class instance.

Richard MacCutchan29-Mar-16 1:42

29-Mar-16 1:42

If the class methods are not exported then how will you access them from unmanaged code?

Leif Simon Goodwin29-Mar-16 4:17

29-Mar-16 4:17

Well, that is the key question isn't it. Smile | :)

I was wondering if there is some equivalent to the manner in which you invoke methods on a COM interface i.e. you effectively tell it the prototype in the code.

Richard MacCutchan29-Mar-16 4:32

29-Mar-16 4:32

You still need to know the prototype in order to call the methods. So how do you access these methods once you have a handle to the class object?

Leif Simon Goodwin29-Mar-16 5:10

29-Mar-16 5:10

At present you add a DllImport with the prototype. So you might hope for something similar for an unmanaged C++ class instance. But apparently not. Ah well.

Incidentally I know that if the DLL exports the class, you can invoke the methods by passing the instance handle as the first argument to the method. But that is not the case I have.

Anyway, the wrapper is written. Smile | :)

Garth J Lancaster29-Mar-16 1:47

Garth J Lancaster

29-Mar-16 1:47

Quote:
The only way I can think of is to create an unmanaged DLL which wraps the other DLL

that would be my first guess, nasty as it is - I needed to use it to do the same sort of thing and 'aggregate' lower level (un-exposed) dll calls into something useable

... Im still looking for a better way myself

Leif Simon Goodwin29-Mar-16 1:49

29-Mar-16 1:49

Thanks Garth. At least you confirm I am probably on the right track!

Reply # 2

Garth J Lancaster29-Mar-16 2:03

Garth J Lancaster

29-Mar-16 2:03

just thinking, have you tried

Quote:
[DllImport("some name.dll", EntryPoint = "_getSc@0",
ExactSpelling = true, CallingConvention = CallingConvention.Cdecl)]

Bernhard Hiller31-Mar-16 0:39

Bernhard Hiller

31-Mar-16 0:39

Did you read How to Marshal a C++ Class[^]?
Well, it uses some kinds of wrappers, as you suggested.

Leif Simon Goodwin3-Apr-16 21:16

How to select Windows explorer's 'Sort by' type programmatically

3-Apr-16 21:16

Thanks, I hadn't seen that, but it assumes that the C++ class is exported by the DLL which was not the case with my DLL.

(The DLL is going to be modified so I can simply import the class methods.)

srikrishnathanthri28-Mar-16 23:32

srikrishnathanthri

28-Mar-16 23:32

Hello,

I am developing a simple Windows search application. I will pass the all the search filters (Name, size etc) to Windows explorer using my application. But I am not getting commands or codes to select the 'Sort by' type programmatically in the window that will open.

Is it possible to implement that ?

Re: How to select Windows explorer's 'Sort by' type programmatically

Garth J Lancaster29-Mar-16 0:05

Garth J Lancaster

29-Mar-16 0:05

how are you interacting with Windows explorer ?

I would have thought a better way was to use

string startFolder = @"c:\start dir\";

// Take a snapshot of the file system.
System.IO.DirectoryInfo dir = new System.IO.DirectoryInfo(startFolder);

// This method assumes that the application has discovery permissions
// for all folders under the specified path.
IEnumerable<System.IO.FileInfo> fileList = dir.GetFiles("*.*", System.IO.SearchOption.AllDirectories);

and then use LINQ to filter fileList

Re: How to select Windows explorer's 'Sort by' type programmatically

srikrishnathanthri29-Mar-16 0:14

srikrishnathanthri

29-Mar-16 0:14

I am interacting with Windows explorer using "Explorer search-ms:" command.

WPF and Unmanaged Liberaries

AmbiguousName28-Mar-16 21:16

AmbiguousName

28-Mar-16 21:16

Hello. I was reading today that wherever possible, WPF use hardware-acceleration by taking advantage of Windows Display Driver Model (WDDM).

Question is: I am using 3rd party unmanaged library which internally uses GDI+. If I am making my front end in WPF, how much better performance should I expect?

Thanks for anything you share.

This world is going to explode due to international politics, SOON.

Re: WPF and Unmanaged Liberaries

Richard MacCutchan28-Mar-16 21:51

Re: WPF and Unmanaged Liberaries

28-Mar-16 21:51

How long is a piece of string?

Seriously, it is impossible to answer such a question. The only way to find out is by running tests on different configurations.

Pete O'Hanlon28-Mar-16 21:55

Pete O'Hanlon

28-Mar-16 21:55

It depends on so many factors, including how you host the DLL inside WPF. As it's not a native WPF component, I suspect you're using an ElementHost and that has performance implications.

This space for rent

Validate form with Ajaxoptions and unobtrusive in partial view

Member 1204569228-Mar-16 9:17

Member 12045692

28-Mar-16 9:17

I have the following View:

<script>
    $(document).ready(function () {
        $('.profile_boxes').click(function () {
            var val = $(this).attr('id');

            $('.profile_boxes').css('background', '#fff');
            $('.profile_boxes').css('border', '1px solid #ededed');

            $("#" + val).css('background', '#f6f6f6');
            $("#" + val).css('border', '1px solid #f55');


            $.ajax({
                url: '@Url.Action("RenderProfilePartials", "NewProfile")',
                data: { 'profile': val },
                cache: false,
                type: "POST",
                dataType: "html",
                success: function (data, textStatus, XMLHttpRequest) {
                    console.log(val);
                    $('#profilePartials').html(data);
                },
                error: function (data, textStatus, XMLHttpRequest) {
                    console.log(data);
                }
            });
        });
    });
</script>
<div class="centering col-lg-6 logged_in_mainboxes">
    <h2>What are you?</h2>
    <div id="band" class="col-lg-4 profile_boxes">
        <h3>Band</h3>
    </div>
    <div id="musican" class="col-lg-4 profile_boxes">
        <h3>Musican</h3>
    </div>
    <div id="regular" class="col-lg-4 profile_boxes">
        <h3>Regular</h3>
    </div>

    @Html.ValidationSummary(false)

    <div id="profilePartials">

    </div>
</div>

When you click on either Band, Musician or Regular, I partial view Is renderd:

HTML

<div id="band_info" class="col-lg-9 profileDesc">
        <p>Maybe some information about the band profile here.....</p>
        @using (Ajax.BeginForm("RegisterBand", "NewProfile", new AjaxOptions() { HttpMethod = "Post" }))
        {
            @Html.ValidationSummary(true, "", new { @class = "text-danger" })
            <div class="form-horizontal">
                <div class="form-group">
                    Bandname
                    <div class="col-md-10">
                        @Html.EditorFor(x => x.Name, new { htmlAttributes = new { @class = "form-control" } })
                        @Html.ValidationMessageFor(x => x.Name, "", new { @class = "text-danger" })
                    </div>
                </div>

                <div class="form-group">
                    Coverpicture
                    <div class="col-md-10">
                        @Html.EditorFor(x => x.CoverPicture, new { htmlAttributes = new { @class = "form-control" } })
                        @Html.ValidationMessageFor(x => x.CoverPicture, "", new { @class = "text-danger" })
                    </div>
                </div>

                <div class="form-group">
                    Description
                    <div class="col-md-10">
                        @Html.EditorFor(x => x.Description, new { htmlAttributes = new { @class = "form-control" } })
                        @Html.ValidationMessageFor(x => x.Description, "", new { @class = "text-danger" })
                    </div>
                </div>

                <div class="form-group">
                    <div class="col-md-offset-2 col-md-10">
                        <input type="submit" value="Spara" class="btn btn-success" />
                    </div>
                </div>
            </div>
        }
</div>

Now I want to validate this forms with Ajaxoptions and unobtrusive. But when I hit Submit, the page Is reloaded and the partial views returned back.

I want it not reload, I want to make the validation without the reload.

Here Is my controller:

[HttpPost]
public ActionResult RegisterBand(BandProfileModel model)
{

    if (ModelState.IsValid == false)
    {
        return PartialView("_BandRegisterPartial", model);
    }


    return View("Index");
}

I have enabled unobtrusive in web.config and all that stuff.

Anyone who can help me?

Re: Validate form with Ajaxoptions and unobtrusive in partial view

Richard MacCutchan28-Mar-16 21:50