The compiler won't find namespace 'System.Windows.Interop'

Question

Help!!**The compiler won't find namespace **'System.Windows.Interop'****

recently I built a winform project,and want to use a dll (do some d3d rendering work) generated by another c++ project;

OS: win7 x64
IDE: vs2013
Language:C#
current framework used in the winform project is ".net framework 4.5"

And in the winform project,I created a class file named MCDllOpt.cs The code is as follow.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Windows.Interop; // Error occured here!

namespace WorldEditor
{
    class MCDllOpt
    {

    }
}

And here's part of what the compiler tells.

1>CoreCompile:
1>  C:\Program Files (x86)\MSBuild\12.0\bin\Csc.exe /noconfig /nowarn:1701,1702,2008 /nostdlib+ /platform:anycpu32bitpreferred /errorreport:prompt /warn:4 /define:TRACE /errorendlocation /preferreduilang:en-US /highentropyva+ /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5.1\Microsoft.CSharp.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5.1\mscorlib.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5.1\System.Core.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5.1\System.Data.DataSetExtensions.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5.1\System.Data.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5.1\System.Deployment.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5.1\System.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5.1\System.Drawing.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5.1\System.Windows.Forms.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5.1\System.Xml.dll" /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5.1\System.Xml.Linq.dll" /debug:pdbonly /filealign:512 /optimize+ /out:obj\Release\WorldEditor.exe /subsystemversion:6.00 /resource:obj\Release\WorldEditor.Form1.resources /resource:obj\Release\WorldEditor.Properties.Resources.resources /target:winexe /utf8output Form1.cs Form1.Designer.cs MCDllOpt.cs Program.cs Properties\AssemblyInfo.cs Properties\Resources.Designer.cs Properties\Settings.Designer.cs "C:\Users\Think\AppData\Local\Temp\.NETFramework,Version=v4.5.1.AssemblyAttributes.cs" obj\Release\\TemporaryGeneratedFile_E7A71F73-0F8D-4B9B-B56E-8E70B10BC5D3.cs obj\Release\\TemporaryGeneratedFile_036C0B5B-1481-4323-8D20-8F5ADCB23D92.cs obj\Release\\TemporaryGeneratedFile_5937a670-0e60-4077-877b-f7221da3dda1.cs
1>F:\WorldEditor\WorldEditor\WorldEditor\MCDllOpt.cs(6,22,6,29): error CS0234: The type or namespace name 'Interop' does not exist in the namespace 'System.Windows' (are you missing an assembly reference?)
1>
1>Build FAILED.
1>
1>Time Elapsed 00:00:00.78
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

After several minutes' searching.I found out that I need to add references specified. But after I add all the references whose prefix is 'System.Windows',the problem's still not fixed!

Does anyone have this problem before? Please help me.

Answer 1

It is a WPF namespace. One assembly you could reference (which contributes classes to that namespace) is PresentationCore.dll. But what classes from System.Windows.Interop do you actually need since you have that using directive? What you need to reference is the assemblies where those classes are.

Maybe the solution is to remove the using?

If you make a WinForm application, possibly you don't need any WPF namespaces?