`ToDictionary` is the way to go. It *does* work - you were just using it incorrectly, presumably. Try this:

    dic = dic.Where(p =&gt; p.Key == 1)
             .ToDictionary(p =&gt; p.Key, p =&gt; p.Value);

Having said that, I assume you *really* want a different `Where` filter, as your current one will only ever find one key...

I changed the maxAllowedContentLength to 

    &lt;security&gt;
        &lt;requestFiltering&gt;
            &lt;requestLimits maxAllowedContentLength=&quot;5024000000&quot; /&gt;
        &lt;/requestFiltering&gt;
    &lt;/security&gt;

In my web.config, but when running on IIS7 I get this error:

&gt;The &#39;maxAllowedContentLength&#39; attribute is invalid. Not a valid unsigned integer

![http://i.stack.imgur.com/u1ZFe.jpg][1]

but when I run in the VS server it run normally without any errors.

How to config my website to allow upload files with 500MB size, without this problem on IIS7?

  [1]: http://i.stack.imgur.com/u1ZFe.jpg

How to set the maxAllowedContentLength to 500MB while running on IIS7?

What does the term &quot;Leaky Abstraction&quot; mean? (Please explain with examples. I often have a hard time grokking a mere theory.)

Meaning of Leaky Abstraction?

I have the following dictionary:

    Dictionary&lt;int,string&gt; dic = new Dictionary&lt;int,string&gt;();
    dic[1] = &quot;A&quot;;
    dic[2] = &quot;B&quot;;

I want to filter the dictionary&#39;s items and reassign the result to the same variable:

    dic = dic.Where (p =&gt; p.Key == 1);

How can I return the result as a dictionary from the same type [`&lt;int,string&gt;`] ?

I tried `ToDictionary`, but it doesn&#39;t work.



How can I filter a dictionary using LINQ and return it to a dictionary from the same type

I have the following dictionary:
<pre><code class="hljs language-csharp">Dictionary&#x3C;int,string> dic = new Dictionary&#x3C;int,string>();
dic[1] = "A";
dic[2] = "B";
</code></pre>
I want to filter the dictionary's items and reassign the result to the same variable:
<pre><code class="hljs language-ini">dic = dic.Where (p => p.Key == 1);
</code></pre>
How can I return the result as a dictionary from the same type [<code>&#x3C;int,string></code>] ?
I tried <code>ToDictionary</code>, but it doesn't work.

how can I get my .exe path because if I copy my .exe I can get my new path ?

get path for my .exe

The title sums it all.

I want to add a text to an existing PDF file using [iTextSharp][1], however i can&#39;t find how to do it anywhere in the web...

PS: I cannot use PDF forms.

  [1]: http://sourceforge.net/projects/itextsharp/

ITextSharp insert text to an existing pdf

I have an asp.net application in which I am using linq for data manipulation. While running, I get the exception &quot;Sequence contains no matching element&quot;.

    if (_lstAcl.Documents.Count &gt; 0)
    {
        for (i = 0; i &lt;= _lstAcl.Documents.Count - 1; i++)
        {
            string id = _lstAcl.Documents[i].ID.ToString();                           
            var documentRow = _dsACL.Documents.First(o =&gt; o.ID == id);
            if (documentRow !=null)
            {

                _lstAcl.Documents[i].Read = documentRow.Read;
                _lstAcl.Documents[i].ReadRule = documentRow.ReadRule;

                _lstAcl.Documents[i].Create= documentRow.Create;
                _lstAcl.Documents[i].CreateRule = documentRow.CreateRule;

                _lstAcl.Documents[i].Update = documentRow.Update;
                _lstAcl.Documents[i].UpdateRule = documentRow.UpdateRule;

                _lstAcl.Documents[i].Delete = documentRow.Delete;
                _lstAcl.Documents[i].DeleteRule = documentRow.DeleteRule;
            }
        }
    }


Sequence contains no matching element

Just curious: Why is the syntax for [try catch in C#][1] (Java also?) hard coded for multiple statements? Why doesn&#39;t the language allow:

    int i;
    string s = DateTime.Now.Seconds % 2 == 1 ? &quot;1&quot; : &quot;not 1&quot;;
    try
       i = int.Parse(s);
    catch
       i = 0;

The example is for trivial purposes only. I know there&#39;s [`int.TryParse`][2].

  [1]: http://msdn.microsoft.com/en-us/library/vstudio/0yd65esw.aspx
  [2]: http://msdn.microsoft.com/en-us/library/system.int32.tryparse.aspx

Why does Try-Catch require curly braces

I stumbled upon this open source project [Fake It Easy][1], and I have to admit, it looks very interesting, however I have my doubts, what are the difference between FIE fakes and say Moq Mocks? Is any one better for particular uses?

EDIT:

What is it about this new framework that would make it better than say Moq? 


  [1]: http://code.google.com/p/fakeiteasy/

Are fakes better than Mocks?

I want to sort a list in C#.

Like where structure property AVC goes to true then show them first then AVC goes to false. Are any way to do this in C# LINQ?

Sort list in C# with LINQ

I am aware of two methods of casting types to `IEnumerable` from an `Arraylist` in Linq and wondering in which cases to use them?

e.g

    IEnumerable&lt;string&gt; someCollection = arrayList.OfType&lt;string&gt;()

or

    IEnumerable&lt;string&gt; someCollection = arrayList.Cast&lt;string&gt;()

What is the difference between these two methods and where should I apply each case?



When to use Cast() and Oftype() in Linq

**Given two** `IEnumerable`s **of the same size, how can I convert it to a** `Dictionary` **using Linq?**

    IEnumerable&lt;string&gt; keys = new List&lt;string&gt;() { &quot;A&quot;, &quot;B&quot;, &quot;C&quot; };
    IEnumerable&lt;string&gt; values = new List&lt;string&gt;() { &quot;Val A&quot;, &quot;Val B&quot;, &quot;Val C&quot; };

    var dictionary = /* Linq ? */;

And the expected output is:

    A: Val A
    B: Val B
    C: Val C

I wonder if there is some simple way to achieve it.

And should I be worried about performance? What if I have large collections?

----------


I don&#39;t if there is an easier way to do it, currently I&#39;m doing like this:

I have an Extension method that will loop the `IEnumerable` providing me the element and the index number.

    public static class Ext
    {
        public static void Each&lt;T&gt;(this IEnumerable els, Action&lt;T, int&gt; a)
        {
            int i = 0;
            foreach (T e in els)
            {
                a(e, i++);
            }
        }
    }

And I have a method that will loop one of the Enumerables and with the index retrieve the equivalent element on the other Enumerable.

    public static Dictionary&lt;TKey, TValue&gt; Merge&lt;TKey, TValue&gt;(IEnumerable&lt;TKey&gt; keys, IEnumerable&lt;TValue&gt; values)
    {
        var dic = new Dictionary&lt;TKey, TValue&gt;();

        keys.Each&lt;TKey&gt;((x, i) =&gt;
        {
            dic.Add(x, values.ElementAt(i));
        });

        return dic;
    }

Then I use it like:

    IEnumerable&lt;string&gt; keys = new List&lt;string&gt;() { &quot;A&quot;, &quot;B&quot;, &quot;C&quot; };
    IEnumerable&lt;string&gt; values = new List&lt;string&gt;() { &quot;Val A&quot;, &quot;Val B&quot;, &quot;Val C&quot; };

    var dic = Util.Merge(keys, values);

And the output is correct:

    A: Val A
    B: Val B
    C: Val C

Map two lists into a dictionary in C#

I am trying to get to grips with LINQ.  The thing that bothers me most is that even as I understand the syntax better, I don&#39;t want to unwittingly sacrifice performance for expressiveness.  

Are they any good centralized repositories of information or books for &#39;Effective LINQ&#39; ?  Failing that, what is your own personal favourite high-performance LINQ technique ?

I am primarily concerned with LINQ to Objects, but all suggestions on LINQ to SQL and LINQ to XML also welcome of course.  Thanks.

LINQ performance FAQ

My question is about enumerating Dictionary elements

    // Dictionary definition
    private Dictionary&lt;string, string&gt; _Dictionary = new Dictionary&lt;string, string&gt;();
    
    // add values using add
    
    _Dictionary.Add(&quot;orange&quot;, &quot;1&quot;);
    _Dictionary.Add(&quot;apple&quot;, &quot;4&quot;);
    _Dictionary.Add(&quot;cucumber&quot;, &quot;6&quot;);
    
    // add values using []
    
    _Dictionary[&quot;banana&quot;] = 7;
    _Dictionary[&quot;pineapple&quot;] = 7;
    
    // Now lets see how elements are returned by IEnumerator
    foreach (KeyValuePair&lt;string, string&gt; kvp in _Dictionary)
    {
      Trace.Write(String.Format(&quot;{0}={1}&quot;, kvp.Key, kvp.Value));
    }

In what order will be the elements enumerated? Can I force the order to be alphabetical?



The order of elements in Dictionary

I want to write a custom class that behaves like `dict` - so, I am inheriting from `dict`.

My question, though, is: Do I need to create a private `dict` member in my `__init__()` method?. I don&#39;t see the point of this, since I already have the `dict` behavior if I simply inherit from `dict`.

Can anyone point out why most of the inheritance snippets look like the one below?

    class CustomDictOne(dict):
       def __init__(self):
          self._mydict = {} 
    
       # other methods follow
    
Instead of the simpler...

    class CustomDictTwo(dict):
       def __init__(self):
          # initialize my other stuff here ...
    
       # other methods follow


Actually, I think I suspect the answer to the question is so that users cannot directly access your dictionary (i.e. they have to use the access methods that you have provided).

However, what about the array access operator `[]`? How would one implement that? So far, I have not seen an example that shows how to override the `[]` operator. 

So if a `[]` access function is not provided in the custom class, the inherited base methods will be operating on a different dictionary?


I tried the following snippet to test out my understanding of Python inheritance:

    class myDict(dict):
        def __init__(self):
            self._dict = {}
    
        def add(self, id, val):
            self._dict[id] = val
    
    
    md = myDict()
    md.add(&#39;id&#39;, 123)
    print md[id]

I got the following error:

&gt; KeyError:  &lt; built-in function id&gt;


What is wrong with the code above?

How do I correct the class `myDict` so that I can write code like this?

    md = myDict()
    md[&#39;id&#39;] = 123



**[Edit]**

I have edited the code sample above to get rid of the silly error I made before I dashed away from my desk. It was a typo (I should have spotted it from the error message).


A python class that acts like dict

I have a class that contains only fields and no methods, like this:


    class Request(object):
        
        def __init__(self, environ):
            self.environ = environ
            self.request_method = environ.get(&#39;REQUEST_METHOD&#39;, None)
            self.url_scheme = environ.get(&#39;wsgi.url_scheme&#39;, None)
            self.request_uri = wsgiref.util.request_uri(environ)
            self.path = environ.get(&#39;PATH_INFO&#39;, None)
            # ...

This could easily be translated to a dict. The class is more flexible for future additions and could be fast with `__slots__`. So would there be a benefit of using a dict instead? Would a dict be faster than a class? And faster than a class with slots?


Should I use a class or dictionary?

I need some sort of way to store key/value pairs where the value can be of different types.

So I like to do:

     int i = 12;
     string s = &quot;test&quot;;
     double x = 24.1;
    
     Storage.Add(&quot;age&quot;, i);
     Storage.Add(&quot;name&quot;, s);
     Storage.Add(&quot;bmi&quot;, x);

And later retrieve the values with:

     int a = Storage.Get(&quot;age&quot;);
     string b = Storage.Get(&quot;name&quot;);
     double c = Storage.Get(&quot;bmi&quot;);

How should a Storage like this look like?
Thanks,
Erik

How do I create a Dictionary that holds different types in C#

From what I understand from the documentation of SelectMany, one could use it to produce a (flattened) sequence of a 1-many relationship.

I have following classes

      public class Customer
      {
        public int Id { get; set; }
        public string Name { get; set; }
      }
    
      class Order
      {
        public int Id { get; set; }
        public int CustomerId { get; set; }
        public string Description { get; set; }
      }


I then try to use them using the query expression syntax like so

      var customers = new Customer[]
      {
        new Customer() { Id=1, Name =&quot;A&quot;},
        new Customer() { Id=2, Name =&quot;B&quot;},
        new Customer() { Id=3, Name =&quot;C&quot;}
      };
    
      var orders = new Order[]
      {
        new Order { Id=1, CustomerId=1, Description=&quot;Order 1&quot;},
        new Order { Id=2, CustomerId=1, Description=&quot;Order 2&quot;},
        new Order { Id=3, CustomerId=1, Description=&quot;Order 3&quot;},
        new Order { Id=4, CustomerId=1, Description=&quot;Order 4&quot;},
        new Order { Id=5, CustomerId=2, Description=&quot;Order 5&quot;},
        new Order { Id=6, CustomerId=2, Description=&quot;Order 6&quot;},
        new Order { Id=7, CustomerId=3, Description=&quot;Order 7&quot;},
        new Order { Id=8, CustomerId=3, Description=&quot;Order 8&quot;},
        new Order { Id=9, CustomerId=3, Description=&quot;Order 9&quot;}
      };
    
      var customerOrders = from c in customers
                           from o in orders
                           where o.CustomerId == c.Id
                           select new 
                                  { 
                                     CustomerId = c.Id
                                     , OrderDescription = o.Description 
                                  };
    
      foreach (var item in customerOrders)
        Console.WriteLine(item.CustomerId + &quot;: &quot; + item.OrderDescription);


This gives to what I need.

    1: Order 1
    1: Order 2
    1: Order 3
    1: Order 4
    2: Order 5
    2: Order 6
    3: Order 7
    3: Order 8
    3: Order 9

I assume this translates to using the SelectMany method when not using the query expression syntax?

Either ways, I&#39;m trying to wrap my head around using SelectMany. So even if my above query does not translate to SelectMany, given the two classes and mock data, could someone provide me with a linq query that uses SelectMany?


Linq - SelectMany Confusion

I have a List(Of DateTime) items. How can I check if all the items are the same with a LINQ query? At any given time there could be 1, 2, 20, 50 or 100 items in the list.


Check if all items are the same in a List

I often see people using `Where.FirstOrDefault()` to do a search and grab the first element. Why not just use `Find()`? Is there an advantage to the other? I couldn&#39;t tell a difference.

    namespace LinqFindVsWhere
    {
        class Program
        {
            static void Main(string[] args)
            {
                List&lt;string&gt; list = new List&lt;string&gt;();
                list.AddRange(new string[]
                {
                    &quot;item1&quot;,
                    &quot;item2&quot;,
                    &quot;item3&quot;,
                    &quot;item4&quot;
                });
    
                string item2 = list.Find(x =&gt; x == &quot;item2&quot;);
                Console.WriteLine(item2 == null ? &quot;not found&quot; : &quot;found&quot;);
                string item3 = list.Where(x =&gt; x == &quot;item3&quot;).FirstOrDefault();
                Console.WriteLine(item3 == null ? &quot;not found&quot; : &quot;found&quot;);
                Console.ReadKey();
            }
        }
    }

Find() vs. Where().FirstOrDefault()

I have a list of `orders`.  
I want to select `orders` based on a set of order statuses.

So essentially `select orders where order.StatusCode in (&quot;A&quot;, &quot;B&quot;, &quot;C&quot;)`

    // Filter the orders based on the order status
    var filteredOrders = from order in orders.Order
                         where order.StatusCode.????????(&quot;A&quot;, &quot;B&quot;, &quot;C&quot;)
                         select order;

Content Type	Original Author	Original Content on Stackoverflow
Question	Homam	View Question on Stackoverflow
Solution 1 - C#	Jon Skeet	View Answer on Stackoverflow

How can I filter a dictionary using LINQ and return it to a dictionary from the same type

C# Problem Overview

C# Solutions

Solution 1 - C#

Meaning of Leaky Abstraction?

How to set the maxAllowedContentLength to 500MB while running on IIS7?

Attributions