I found the following code snippet on CodeProject on calling methods asynchronously at ... http://www.codeproject.com/Articles/14931/Asynchronous-Method-Invocation

private void CallFooWithOutAndRefParameters()
{
    // create the paramets to pass to the function
    string strParam1 = "Param1";
    int intValue = 100;
    ArrayList list = new ArrayList();
    list.Add("Item1");

    // create the delegate
    DelegateWithOutAndRefParameters delFoo =
      new DelegateWithOutAndRefParameters(FooWithOutAndRefParameters);

    // call the beginInvoke function!
    IAsyncResult tag =
        delFoo.BeginInvoke(strParam1,
            out intValue,
            ref list,
            null, null);

    // normally control is returned right away,
    // so you can do other work here...

    // calling end invoke notice that intValue and list are passed
    // as arguments because they might be updated within the function.
    string strResult =
        delFoo.EndInvoke(out intValue, ref list, tag);

    // write down the parameters:
    Trace.WriteLine("param1: " + strParam1);
    Trace.WriteLine("param2: " + intValue);
    Trace.WriteLine("ArrayList count: " + list.Count);
    Trace.WriteLine("return value: " + strResult);
}

There are a couple of things I don't understand about this code.

Per the comment control is returned immediately to the calling code when it hits the BeginInvoke line.

Does that mean that the code that follows (EndInvoke followed by some trace logging) only runs after the FooWithOutAndRefParameters call completes...automagically (even though that code resides in the same method). It looks a little confusing to me. (I have always used callbacks for this kind of thing.)

Using this method do I HAVE to call EndInvoke. Can I just invoke the method asyncronously and forget it happened? Any downsides to this?

If I don't call EndInvoke (as is shown in this method) should I then always have a callback? Even if the callback does nothing.

If the answers YOU SHOULD...then do you call EndInvoke OR define a callback? (The advantage to defining a callback being that you are notified of the result)

BTW I know I could check for errors or log resuls in the EndInvoke or callback (and I might in fact do that). What I was wondering is ARE THERE RISKS from not calling EndInvoke or defining a callback (memory leaks for example)? What is the best practice.

Seth

        <p>Yesterday I worked on an MVC 3 project in Visual Studio 2010 and then shut down Visual Studio before leaving work.</p>

This morning when I try to load the same project in Visual Studio the project hangs. I have restarted my computer, disabled all add-ons and extensions that I could. Still no banana.

I have no idea how to troubleshoot this. I would try to clean the solution if I could get it to load but I can't. (Can I clean the solution from the VS command window?).

Any help would be greatly appreciated. How do I troubleshoot this?

Seth

Hello,

I have code/support an application built on .NET framework that has always run on .NET 2. This year we are upgrading the application to use .NET 3.5 (or 4?).

In preparing for this change we noticed that that Offline Installer (required for our customer base) for .NET 3.5 is 200+ MBs bigger than the .NET 4 offline installer.

Here are my questions.

Why is the dotnet 3.5 installer so much bigger than the 4 offline installer?

Can we TARGET .NET 3.5 but distribute .NET 4. In other words, is .NET 4 backwards compatible? Assuming that .NET 4 was the only installed .NET could application still target earlier frameworks?

IF our application is compiled for x86 CPU (rather than Any CPU) do you still have to distribute the x64/x86 Client Profile or can we just distribute the x86 Client Profile? In other words, can we distribute the x86 Client Profile even though it will be installed on x64 machines if our app is compiled for x86 target CPU? Any risks or gotchas for doing this?

The issue is that if we upgrade our app to target .NET 4 there are a lot of application servers that we also have to upgrade which effects a number of other applications. Any thoughts?

Seth

I have code/support an application built on .NET framework that has always run on .NET 2. This year we are upgrading the application to use .NET 3.5 (or 4?).

In preparing for this change we noticed that that Offline Installer (required for our customer base) for .NET 3.5 is 200+ MBs bigger than the .NET 4 offline installer.

Here are my questions.

Why is the dotnet 3.5 installer so much bigger than the 4 offline installer?

Can we TARGET .NET 3.5 but distribute .NET 4. In other words, is .NET 4 backwards compatible? Assuming that .NET 4 was the only installed .NET could application still target earlier frameworks?

IF our application is compiled for x86 CPU (rather than Any CPU) do you still have to distribute the x64/x86 Client Profile or can we just distribute the x86 Client Profile? In other words, can we distribute the x86 Client Profile even though it will be installed on x64 machines if our app is compiled for x86 target CPU? Any risks or gotchas for doing this?

The issue is that if we upgrade our app to target .NET 4 there are a lot of application servers that we also have to upgrade which effects a number of other applications. Any thoughts?

Seth

I am almost positive that the answer is YES. If I use a Try Finally block but do not use a Catch block then any exceptions WILL bubble. Correct?

Any thoughts on the practice in general?

Seth

I am almost positive that the answer is YES. If I use a Try Finally block but do not use a Catch block then any exceptions WILL bubble. Correct?

Any thoughts on the practice in general?

Seth

I am using LinqPad to learn Linq by querying the NetFlix OData source.

(BTW I know their is a similar question already on SO...didn't help me).

Here is the query I got working which is awesome.

from x in Titles
//where x.Rating=="PG"
where x.Instant.Available==true
where x.AverageRating>=4.0
//where x.Rating.StartsWith("TV")
//where x.Genres.First (g => g.Name.Contains("Family") ) //(from y in Genres where y.Name.Contains("Family") select y)
//where x.Genres.First (g => g.Name=="")
//orderby x.Name
orderby x.AverageRating descending
//select x
//)
select new {x.Name, x.Rating, x.AverageRating, x.ShortSynopsis}

(Pardon all the comments...it is a testament to the fact I am experimenting and that I will change the query for various needs).

There are two thing I cannot figure out.

First. Let's say I only want to return the first 10 results.

Second (and most importantly). I want to filter by a partial string of the genre. Each title contains a Genres collection. I want to show only Genres where the Name contains a certain string (like "Family"). Even better filter using Titles where genre.name.contains "firstFilter" AND "secondFilter".

Basically, I want to filter by genre(s) and I cannot figure out how to do it since Title contains its own Genres collection and I cannot figure out how to return only title that are in one or more genres of the collection.

Thanks for your help!

ps...it seems that Netflix OData source does not support Any operator.

Seth

I want to load a dictionary at startup in my console app from my app.config.

I know that I could use an xml library or linq to XML to load it to parse and traverse it. My question is there a BUILT IN way of doing it.

Isn't there some way to add an application configuration section into the app.config and then have it loaded automagically using ConfigurationManager class in the System.Configuration namespace?

Any example? BTW, I am in NET20.

EDIT
Sorry, I should have clarified. I want to load the dictionary WITHOUT using AppSettings. I know how to do that already. Of course, the downside of using AppSettings is that I have to change my code to add new values to my dictionary. That is why I am looking for a way to do it automatically.

I am a vb.net programmer switching to C#.

I have the following code for a console application (targeting NET20)

using System;
using System.IO;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;


namespace eScoreSwapper
{
    class Program
    {
        private string _dbName = ConfigurationManager.AppSettings["dbName"];

        static void Main(string[] args) {}

        static void InitVars()
        {
            if (string.IsNullOrEmpty(_dbName)) _dbName = "";
        }
    }
}

This is giving a compile error in the if clause of InitVars for the _dbName variable:

Error   1   An object reference is required for the non-static field, method, or property 'eScoreSwapper.Program._dbName'   C:\Users\SethS\Documents\eScore\Versions\Trunk\dotNet\eScoreSwapper\eScoreSwapper\Program.cs    26  38  eScoreSwapper

Is it because it is true. C# does not allow you to reference private class fields unless they are declared static? I am sure I am doing something wrong.

While I am at it can I ask another C# question. Why is the if statement valid? Why are braces not required? Is it valid syntax as long as if condition is followed by a single expression (as in t-sql IF ).

Thanks for your help.

Seth

In C# I can test for this...

public event EventHandler Trigger;
protected void OnTrigger(EventArgs e)
{
    if (Trigger != null)
        Trigger(this, e);
}

Is there a way to do this in VB.NET? Test for null I mean?

MORE INFO

I forgot to mention. I have classes written in C# but I am writing my unit tests in VB.NET.

I am trying this in the unit test...

If myObject.Trigger IsNot Nothing Then  
    ''#do something
End If

This is causing a compile time error which says ... "Public Event Trigger is an Event and cannot be called directly. Use the RaiseEvent statement to raise an event."

Seth