Can I use a regular System.dll in a Compact Framework project?

Question

In my test Winforms app (in which I'm targeting .NET 3.5, to simulate the Windows CE / Compact Framework 3.5 app that this is a first-line test for as much as possible), I added some JSON.NET code to deserialize json returned from WebAPI methods:

try
{
    const string uri = "http://localhost:48614/api/departments";
    var webRequest = (HttpWebRequest)WebRequest.Create(uri);
    var webResponse = (HttpWebResponse)webRequest.GetResponse();
    if ((webResponse.StatusCode == HttpStatusCode.OK) && (webResponse.ContentLength > 0))
    {
        var reader = new StreamReader(webResponse.GetResponseStream());
        string s = reader.ReadToEnd();
        MessageBox.Show(string.Format("Content from HttpWebRequest is {0}", s));
        var arr = JsonConvert.DeserializeObject<JArray>(s);
        int i = 1;
        foreach (JObject obj in arr)
        {
            var id = (string)obj["Id"];
            var accountId = (double)obj["AccountId"];
            var departmentName = (string)obj["DeptName"];
            MessageBox.Show(string.Format("Object {0} in JSON array: id == {1}, accountId == {2}, deptName == {3}", i, id, accountId, departmentName));
            i++;
        }
    }
    else
    {
        MessageBox.Show(string.Format("Status code == {0}", webResponse.StatusCode));
    }
}
catch (Exception ex)
{
    MessageBox.Show(ex.Message);
}

...This runs fine in the .NET 3.5 Winforms app, but when I copied it over to the Windows CE-targetted app, the code wouldn't run, with the following errors spilling forth:

The type 'System.ComponentModel.IBindingList' is defined in an assembly that is not referenced. You must add a reference to assembly 'System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'

The type 'System.ComponentModel.ITypedList' is defined in an assembly that is not referenced. You must add a reference to assembly 'System, Version=2.0.0.0...

The type 'System.ComponentModel.INotifyPropertyChanging' is defined in an assembly that is not referenced....

The type 'System.ComponentModel.ICustomTypeDescriptor' is defined in an assembly...

The type 'System.ComponentModel.INotifyPropertyChanged' ...

The type 'System.Uri'...

I saw that in the Winforms (testbed) app, I'm using version 2.0.0.0 of the "regular" (or "deluxe" when compared to CF) System.dll. In the Windows CE app, though, I was using the CF flavor of version 3.5 found here: C:\Program Files (x86)\Microsoft.NET\SDK\CompactFramework\v3.5\WindowsCE\System.dll

I tried using version 2 CF from C:\Program Files (x86)\Microsoft.NET\SDK\CompactFramework\v2.0\WindowsCE\System.dll, but that failed, too - so it's apparently not really the version (3.5 vs. 2.0), but the "flavor" (CF vs "deluxe"/regular System.dll).

SO...I replaced the CF-flavored System.dll[s] with the one successfully used by the Winforms test app, explicitly the one in C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.dll (I have no System.dll in C:\Windows\Microsoft.NET\Framework\v3.5, anyway).

It no longer gives those same err msgs as listed above, but there is another compile error that may (or may not be) related (Can I give an emulator more disk space?) now.

Whether it is or not (related), it brings up the intriguing question: Will using a regular System.dll in a Windows CE project cause a problem?

If it will -- or there's a good chance that it will -- cause a problem, since it was apparently the JSON.NET code that required the change to an "off-colored" version of System.dll, is there a CF-ready / CF-specific version of JSON.NET? Will I have to create my own CF-targeted version of an assembly from the JSON.NET source?

UPDATE

In the JSON.NET readme, it states:

For a Compact Framework 3.5 build download Json.NET 3.5.

Which I assumed meant the .DLL in \Json50r7\Bin\Net35

Am I wrong about that?

UPDATE 2

When I attempt to open Newtonsoft.Json.Net35.sln in Windows 2008, with the intention of creating a CE-targeted assembly, it doesn't allow me, saying, "The selected file is a solution file, but was created by a newer version of this appllication and cannot be opened*"

It also says in the JSON.NET read me:

Microsoft stopped support for the Compact Framework in Visual Studio 2010.

...so I don't think I can open it in a newer version of VS2008 and create a CF-friendly DLL, either...

UPDATE 3

Looking for a "Compact" folder in the download from http://json.codeplex.com/releases/view/113546, but I see no such folder:

It's not the "Portable" folder, is it?

Answer 1

As Robert Harvey suggests, the tile and the actual question here don't match. You probably should fix that.

The answer to the current title "Can I use a regular System.dll in a Compact Framework Project?" is absolutely, definitively no. You cannot mix and match. Full-framework assemblies cannot run under the Compact Framework. There's no way to make them work. Period. Stop trying this.

The answer to "How do I use JSON.NET is a Compact Framework Project" is that you should go to the JSON.NET project site on GitHub and specifically look at the last JSON.NET 3.5 release (it was Release 8) and download it. Inside that zip file is a folder named "Compact" that contains an assembly named Newtonsoft.Json.Compact.dll. Add a reference to that DLL to your Compact Framework 3.5 project.