You can specify that you want to use a generic list instead of an array by clicking the advanced button when you add a reference, or you can right click on the service reference and choose configure to change it in place.

The reason is that WCF serializes Generic lists as arrays to send across the wire. The configuration is just telling svcutil to create a proxy that converts them back to a generic list for your convenience.

When you use `svcutil.exe` to create you client code you need to tell it how to resolve certain references that are not available to it.

This is how you would do it for `List&lt;T&gt;`:

    svcutil /o:YourService.cs /ct:System.Collections.Generic.List`1 http://example.com/mex

Stever B is correct.  WCF tries really hard not to be coupled to .NET.  You may want to allow a Java client to connect to your component.  Arrays are interoperable.  Generic .NET lists aren&#39;t.

However, you&#39;re more than welcome to create your own proxy class that will convert the array back into a List&lt;T&gt; or anything else that you&#39;d like.  The nice thing about manually creating your own proxies is that you&#39;re in complete control of what they do.

When you add the service reference to the client project click the advanced button and change collection type from array to what you want it to be...

I have two pdf or postscript files (I can work with either one).  What I want to do is merge each page on top of the other so that page1 of document A will be combined with page 1 of document B to produce page 1 of the output document.  This isn&#39;t something I necessarily want need to do programatically, although that would be helpful.

Any ideas?

overlay one pdf or ps file on top of another

I&#39;ve discovered this idiom recently, and I am wondering if there is something I am missing. I&#39;ve never seen it used. Nearly all Java code I&#39;ve worked with in the wild favors slurping data into a string or buffer, rather than something like this example (using HttpClient and XML APIs for example):

        final LSOutput output; // XML stuff initialized elsewhere
        final LSSerializer serializer;
        final Document doc;
        // ...
        PostMethod post; // HttpClient post request
        final PipedOutputStream source = new PipedOutputStream();
        PipedInputStream sink = new PipedInputStream(source);
        // ...
        executor.execute(new Runnable() {
                public void run() {
                    output.setByteStream(source);
                    serializer.write(doc, output);
                    try {
                        source.close();
                    } catch (IOException e) {
                        throw new RuntimeException(e);
                    }
                }});

        post.setRequestEntity(new InputStreamRequestEntity(sink));
        int status = httpClient.executeMethod(post);

That code uses a Unix-piping style technique to prevent multiple copies of the XML data being kept in memory. It uses the HTTP Post output stream and the DOM Load/Save API to serialize an XML Document as the content of the HTTP request. As far as I can tell it minimizes the use of memory with very little extra code (just the few lines for `Runnable`, `PipedInputStream`, and `PipedOutputStream`).

So, what&#39;s wrong with this idiom? If there&#39;s nothing wrong with this idiom, why haven&#39;t I seen it?

EDIT: to clarify, `PipedInputStream` and `PipedOutputStream` replace the boilerplate buffer-by-buffer copy that shows up everywhere, and they also allow you to process incoming data concurrently with writing out the processed data. They don&#39;t use OS pipes.



Why doesn&#39;t more Java code use PipedInputStream / PipedOutputStream?

I am returning a List&lt;T&gt; from my WCF method.  In my client code, it&#39;s return type shows as MyObject[].  I have to either use MyObject[], or IList, or IEnumerable... 

    WCFClient myClient = new WCFClient();

        MyObject[] list = myClient.GetMyStuff();
    or
        IList&lt;MyObject&gt; list = myClient.GetMyStuff();
    or
        IEnumerable&lt;MyObject&gt; list = myClient.GetMyStuff();

All I am doing is taking this collection and binding it to a grid.  What is the best object to assign my returned collection?

Why does WCF return myObject[] instead of List&lt;T&gt; like I was expecting?

I am returning a List<t> from my WCF method. In my client code, it's return type shows as MyObject[]. I have to either use MyObject[], or IList, or IEnumerable...</t>
<pre><code class="hljs language-ini">WCFClient myClient = new WCFClient();

 MyObject[] list = myClient.GetMyStuff();
or
 IList&#x3C;MyObject> list = myClient.GetMyStuff();
or
 IEnumerable&#x3C;MyObject> list = myClient.GetMyStuff();
</code></pre>
All I am doing is taking this collection and binding it to a grid. What is the best object to assign my returned collection?

I want to make a [C#][1] program that can be run as a CLI or GUI application depending on what flags are passed into it. Can this be done?

I have found these related questions, but they don&#39;t exactly cover my situation:

- [How to write to the console in a GUI application][2]
- [How do I get console output in C++ with a Windows program?][3]

  [1]: http://en.wikipedia.org/wiki/C_Sharp_%28programming_language%29
  [2]: https://stackoverflow.com/questions/192294/how-to-write-to-the-console-in-a-gui-application
  [3]: https://stackoverflow.com/questions/191842/how-do-i-get-console-output-in-c-with-a-windows-program


Can one executable be both a console and GUI application?

I am trying to determine if two `HashSet` objects in .NET 3.5 (C#) are equal sets, *i.e.* contain the same values. This seems like something one would obviously want to do but none of the provided functions seem to give you this information.

The way I can think to do this is by checking if the count of the two sets are equal *and* one set is a subset (not proper) of the other. I think the only way that can happen is if they are equal sets. Example code:

    HashSet&lt;int&gt; set1 = new HashSet&lt;int&gt;();
    set1.Add(1);
    set1.Add(2);
    set1.Add(3);
    
    HashSet&lt;int&gt; set2 = new HashSet&lt;int&gt;();
    set2.Add(1);
    set2.Add(2);
    set2.Add(3);
    
    if(set1.Count == set2.Count &amp;&amp; set1.IsSubsetOf(set2))
    {
        // do something
    }

Would this always work? Is there a better way? Why doesn&#39;t `HashSet` have a  `public bool IsEqualSetWith()` function?

How do you determine if two HashSets are equal (by value, not by reference)?

I&#39;m writing an integration test where I will be inserting a number of objects into a database and then checking to make sure whether my method retrieves those objects.

My connection to the database is through NHibernate...and my usual method of creating such a test would be to do the following:

    NHibernateSession.BeginTransaction();
    
    //use nhibernate to insert objects into database
    //retrieve objects via my method
    //verify actual objects returned are the same as those inserted
    
    NHibernateSession.RollbackTransaction();

However, I&#39;ve recently found out about [TransactionScope][1] which apparently can be used for this very purpose...

Some [example code I&#39;ve found][2] is as follows:

    public static int AddDepartmentWithEmployees(Department dept)
    {
    
        int res = 0;
    
        DepartmentAdapter deptAdapter = new DepartmentAdapter();
        EmployeeAdapter empAdapter = new EmployeeAdapter();
        using (TransactionScope txScope = new TransactionScope())
        {
    
            res += deptAdapter.Insert(dept.DepartmentName);
            //Custom method made to return Department ID 
            //after inserting the department &quot;Identity Column&quot;
            dept.DepartmentID = deptAdapter.GetInsertReturnValue();
            foreach(Employee emp in dept.Employees)
            {
    
                emp.EmployeeDeptID = dept.DepartmentID;
                res += empAdapter.Insert(emp.EmployeeName, emp.EmployeeDeptID);
    
            }
            txScope.Complete();
    
        }
        return res;
    
    }

I believe that if I don&#39;t include the line `txScope.Complete()` that the data inserted will be rolled back. But unfortunately I don&#39;t understand how that is possible... how does the `txScope` object keep a track of the `deptAdapter` and `empAdapter` objects and their transactions on the database.

I feel like I&#39;m missing a bit of information here...am I really able to replace my `BeginTransaction()` and `RollbackTransaction(`) calls by surrounding my code using `TransactionScope`?

If not, how then does `TransactionScope` work to roll back transactions?

  [1]: http://msdn.microsoft.com/en-us/library/system.transactions.transactionscope.aspx
  [2]: http://dotnetslackers.com/articles/ado_net/Managing_Transactions_using_TransactionScope.aspx

How does TransactionScope roll back transactions?

Why can&#39;t you create a generic indexer in .NET?

the following code throws a compiler error:

    public T this&lt;T&gt;[string key]
    {
        get =&gt; /* Return generic type T. */
    }

Does this mean you can&#39;t create a generic indexer for a generic member collection?

Why it is not possible to define generic indexers in .NET?

I want to use a collection initializer for the next bit of code:

    public Dictionary&lt;int, string&gt; GetNames()
    {
        Dictionary&lt;int, string&gt; names = new Dictionary&lt;int, string&gt;();
        names.Add(1, &quot;Adam&quot;);
        names.Add(2, &quot;Bart&quot;);
        names.Add(3, &quot;Charlie&quot;);
        return names;
    }

So typically it should be something like:

    return new Dictionary&lt;int, string&gt;
    { 
       1, &quot;Adam&quot;,
       2, &quot;Bart&quot;
       ...

But what is the correct syntax for this?



Can I use a collection initializer for Dictionary&lt;TKey, TValue&gt; entries?

I am getting this exception: 

&gt; _The communication object,
&gt; System.ServiceModel.Channels.ServiceChannel,
&gt; cannot be used for communication
&gt; because it is in the Faulted state._

The WCF service uses the default wsHttpBinding. I am using WCF in the following way wherever I am using it:

    using (var proxy = new CAGDashboardServiceClient())
    {
        proxy.Open();
        var result = proxy.GetSiteForRegion(ddlRegions.SelectedValue);
        ddlSites.DataSource = result;
        ddlSites.DataBind();
        proxy.Close();
    }

The error line shown in the message seems to be after last proxy.close. Not sure what is going on. I am launching the service from within visual studio 08.

Here is the trace information:

&lt;!-- language: none --&gt;

    The communication object, System.ServiceModel.Channels.ServiceChannel, cannot be used for communication because it is in the Faulted state.
    
    Server stack trace: 
      at System.ServiceModel.Channels.CommunicationObject.Close(TimeSpan timeout)
    
    Exception rethrown at [0]: 
      at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
      at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData&amp; msgData, Int32 type)
      at System.ServiceModel.ICommunicationObject.Close(TimeSpan timeout)
      at System.ServiceModel.ClientBase`1.System.ServiceModel.ICommunicationObject.Close(TimeSpan timeout)
      at System.ServiceModel.ClientBase`1.Close()
      at System.ServiceModel.ClientBase`1.System.IDisposable.Dispose()
      at CAGDashboard.UserControls.ucVolunteerCRUDGrid.ddlRegions_SelectedIndexChanged(Object sender, EventArgs e) in C:\Documents and Settings\rballalx\My Documents\Visual Studio 2008\Projects\DashboardCAG\CAGDashboard\UserControls\ucVolunteerCRUDGrid.ascx.cs:line 81
      at System.Web.UI.WebControls.ListControl.OnSelectedIndexChanged(EventArgs e)
      at System.Web.UI.WebControls.DropDownList.RaisePostDataChangedEvent()
      at System.Web.UI.WebControls.DropDownList.System.Web.UI.IPostBackDataHandler.RaisePostDataChangedEvent()
      at System.Web.UI.Page.RaiseChangedEvents()
      at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)


How to make sure you don&#39;t get WCF Faulted state exception?

The netsh command wants an appid ([see here][1]) :

    netsh http add sslcert ipport=0.0.0.0:8000 certhash=0000000000003ed9cd0c315bbb6dc1c08da5e6 appid={00112233-4455-6677-8899-AABBCCDDEEFF} 

I&#39;ve not been able so far to understand how I&#39;m supposed to know the GUID netsh wants me to provide. Any hints?


  [1]: http://msdn.microsoft.com/en-us/library/ms733791.aspx

What appid should I use with netsh.exe?

Can I do the following?

	[OperationContract]
	[WebGet(UriTemplate = &quot;/foo/{id}&quot;)]
	string GetFoo(int id);

I&#39;d like my service to function as both RESTful service and RPC-style SOAP service.
If possible I&#39;d like to retain int as int, and not do parsing by hand.

Can I pass non-string to WCF RESTful service using UriTemplate?

In wcf, what is the difference between applying the `DataMember` attribute on a property  
    
    private int m_SomeValue;
    
    [DataMember]  
    public int SomeValue {
      get {...}
      set {...}
    }
instead of a member variable  
    
    [DataMember]  
    private int m_SomeValue;
    
    public int SomeValue {
      get {...}
      set {...}
    }
?


WCF: DataMember attribute on property vs. member

I built a web application containing a WCF service contract and a Silverlight control which makes calls to that WCF service. On my development and test servers it works great. 

When I deploy to our live server and run the application I get an exception of type `System.ServiceModel.ServiceActivationException` which states that the service can not be activated due to an exception during compilation.  The exception is:

&gt; This collection already contains an address with scheme http. There can be at most one address per scheme in this collection.

I read that this exception may be thrown if the web site has more than one host header, which is true on our live server.  Apparently WCF services hosted in IIS can have only one base address.  How can I get around this issue?

WCF service startup error &quot;This collection already contains an address with scheme http&quot;

I&#39;m writing some Scala code which uses the [Apache POI][1] API. I would like to iterate over the rows contained in the `java.util.Iterator` that I get from the Sheet class. I would like to use the iterator in a `for each` style loop, so I have been trying to convert it to a native Scala collection but will no luck.

I have looked at the Scala wrapper classes/traits, but I can not see how to use them correctly. How do I iterate over a Java collection in Scala without using the verbose `while(hasNext()) getNext()` style of loop?

Here&#39;s the code I wrote based on the correct answer:

    class IteratorWrapper[A](iter:java.util.Iterator[A])
    {
        def foreach(f: A =&gt; Unit): Unit = {
            while(iter.hasNext){
              f(iter.next)
            }
        }
    }

    object SpreadsheetParser extends Application
    {
        implicit def iteratorToWrapper[T](iter:java.util.Iterator[T]):IteratorWrapper[T] = new IteratorWrapper[T](iter)

        override def main(args:Array[String]):Unit =
        {
            val ios = new FileInputStream(&quot;assets/data.xls&quot;)
            val workbook = new HSSFWorkbook(ios)
            var sheet = workbook.getSheetAt(0)
            var rows = sheet.rowIterator()

            for (val row &lt;- rows){
                println(row)
            }
        }
    }

  [1]: http://en.wikipedia.org/wiki/Apache_POI


Iterating over Java collections in Scala

I have an `ArrayList`, a Collection class of Java, as follows:

    ArrayList&lt;String&gt; animals = new ArrayList&lt;String&gt;();
    animals.add(&quot;bat&quot;);
    animals.add(&quot;owl&quot;);
    animals.add(&quot;bat&quot;);
    animals.add(&quot;bat&quot;);

As you can see, the `animals` `ArrayList` consists of 3 `bat` elements and one `owl` element. I was wondering if there is any API in the Collection framework that returns the number of `bat` occurrences or if there is another way to determine the number of occurrences.

I found that Google&#39;s Collection `Multiset` does have an API that returns the total number of occurrences of an element. But that is compatible only with JDK 1.5. Our product is currently in JDK 1.6, so I cannot use it.



How to count the number of occurrences of an element in a List

How would you initialise a static `Map` in Java?

Method one: static initialiser &lt;br&gt;
Method two: instance initialiser (anonymous subclass)
or
some other method?

What are the pros and cons of each?

Here is an example illustrating the two methods:

    import java.util.HashMap;
    import java.util.Map;
    
    public class Test {
        private static final Map&lt;Integer, String&gt; myMap = new HashMap&lt;&gt;();
        static {
            myMap.put(1, &quot;one&quot;);
            myMap.put(2, &quot;two&quot;);
        }
    
        private static final Map&lt;Integer, String&gt; myMap2 = new HashMap&lt;&gt;(){
            {
                put(1, &quot;one&quot;);
                put(2, &quot;two&quot;);
            }
        };
    }

How can I initialise a static Map?

Is there a way that you can get a collection of all of the Models in your Rails app?

Basically, can I do the likes of: -

    Models.each do |model|
      puts model.class.name
    end

Content Type	Original Author	Original Content on Stackoverflow
Question	ScottG	View Question on Stackoverflow
Solution 1 - C#	Stever B	View Answer on Stackoverflow
Solution 2 - C#	Andrew Hare	View Answer on Stackoverflow
Solution 3 - C#	Tad Donaghe	View Answer on Stackoverflow
Solution 4 - C#	Jason Punyon	View Answer on Stackoverflow

Why does WCF return myObject[] instead of List<T> like I was expecting?

C# Problem Overview

C# Solutions

Solution 1 - C#

Solution 2 - C#

Solution 3 - C#

Solution 4 - C#

Why doesn't more Java code use PipedInputStream / PipedOutputStream?

overlay one pdf or ps file on top of another

Attributions