c# - Silverlight in browser UnitTesting Mock<FileInfo> -

i'm facing difficulties in silverlight (inbrowser) unittesting using mock read file viewmodel.

 gives me accessdenied error message. there alternative method kind of problem?   unittesting draganddrop image file in silverlight 4. 

eg: unittesing.cs

var fileinfo = new mock(); //i can't mock fileinfo

var fileinfo = new fileinfo("test.jpg");

---

thanks jonny, did follow , not working , here sample code snipped.

new interface class

public interface ifileinfo { string name {get;set ;} filestream open(filemode mode); }

new wrapper class

public class fileinfowrapper : ifileinfo { private fileinfo fileinfo; public filestream openread() { return this.openread(); } public string name { { return this.name; } set { this.name = value; } }

}

in test class

[testmethod] [asynchronous] public void multifiledroptest() { list wrapperlist = new list(); fileinfo.setup(fl => fl.name).returns("testing.jpg");

    fileinfo.setup<stream>(fl => fl.openread()).returns(filestream.object);      wrapperlist .add(fileinfo.object);     wrapperlist .add(fileinfo.object);      idataobject.setup(p => p.getdata(dataformats.filedrop)).returns(wrapperlist .toarray()); 

}

// function (viewmodel) public bitmapimage singleimagedroptest(idataobject idata) { ............. var files = (fileinfo[])dataobject.getdata(dataformats.filedrop);

        ...taking first file files collection         fileinfo file = files[0];          if (file != null && isimagefile(file.extension))         { 

//file read , return bitmap code working fine } }

from code you've written i'm guessing you're trying use moq framework, uses syntax

var fileinfo = new mock<interface>(); 

you need supply type, framework has clue of behaviour expect.

in case, won't able substitute interface fileinfo, since fileinfo concrete class. alternatives are:

1. find abstract class or interface fileinfo class implements, has methods need use, , when using variable on view, declare type

2. (more likely) make class wraps fileinfo class, , interface implements, includes method(s) need, , declare variable on view interface type.