Put your cursor in the anonymous function (between the {}&#39;s) and press &lt;kbd&gt;F9&lt;/kbd&gt;.

Recently I wrote a project with maven, but I have a question about the version in maven pom.xml.

If I write such a dependency
&lt;!-- language-all: lang-xml --&gt;

    &lt;dependency&gt;
        &lt;groupId&gt;foo&lt;/groupId&gt;
        &lt;artifactId&gt;bar&lt;/artifactId&gt;
         &lt;!--No version here--&gt;
    &lt;/dependency&gt;

what will the version be

1. in a simple project, no subproject

2. as a dependency in another project and that project use foo-bar-1.0.0

What will the version be when I don&#39;t specify it in the Maven&#39;s pom.xml?

I save files in a specific folder at run time. After some time, I want to delete them programmatically. How do I delete all files from a specific folder?


How to delete all files from a specific folder?

I quickly want to determine whether/when a set of events are triggered. Therefore I quickly assigned empty lambda&#39;s to them.

    _session.TopologyStarted += () =&gt; { };

When tracing through the code when the event is triggered, the debugger goes into the anonymous function, allowing to debug it&#39;s execution. However, when setting a breakpoint on this line of code, a breakpoint is set on the assignment of the anonymous function to the event.

Is there a way to set a breakpoint within the anonymous function?

Is it possible to set a breakpoint in anonymous functions?

I quickly want to determine whether/when a set of events are triggered. Therefore I quickly assigned empty lambda's to them.
<pre><code class="hljs language-ini">_session.TopologyStarted += () => { };
</code></pre>
When tracing through the code when the event is triggered, the debugger goes into the anonymous function, allowing to debug it's execution. However, when setting a breakpoint on this line of code, a breakpoint is set on the assignment of the anonymous function to the event.
Is there a way to set a breakpoint within the anonymous function?

We are developer, and we have a digital signed application installer. When we install this application, it popups out the smart screen which affects the installing experience. It says 

&gt; **Windows protected your PC**
&gt; 
&gt; Windows SmartScreen prevented an unrecognized app from starting,
&gt; Running this app might put your PC at risk.

I think Microsoft has some strategy to verify the application besides the digital signature. Has anyone has the experience for this issue and please give me some clue to fix this issue?

How to pass the smart screen on Win8 when install a signed application?

I have some questions regarding the the singleton pattern as documented here:
http://msdn.microsoft.com/en-us/library/ff650316.aspx

The following code is an extract from the article:

    using System;
    
    public sealed class Singleton
    {
       private static volatile Singleton instance;
       private static object syncRoot = new object();
    
       private Singleton() {}
    
       public static Singleton Instance
       {
          get 
          {
             if (instance == null) 
             {
                lock (syncRoot) 
                {
                   if (instance == null) 
                      instance = new Singleton();
                }
             }

             return instance;
          }
       }
    }

Specifically, in the above example, is there a need to compare instance to null twice, before and after the lock? Is this necessary? Why not perform the lock first and make the comparison?

Is there a problem in simplifying to the following?

       public static Singleton Instance
       {
          get 
          {
            lock (syncRoot) 
            {
               if (instance == null) 
                  instance = new Singleton();
            }

             return instance;
          }
       }

Is the performing the lock expensive?


Thread Safe C# Singleton Pattern

... or *how I learned to stop worrying and just write code against completely undocumented APIs from Microsoft*. Is there any actual documentation of the official `System.Web.Optimization` release? &#39;cuz I sure can&#39;t find any, there&#39;s no XML docs, and all the blog posts refer to the RC API which is substantially different. Anyhoo..

I am writing some code to automatically resolve javascript dependencies and am creating bundles on the fly from those dependencies. Everything works great, except if you edit scripts or otherwise make changes that would affect a bundle without restarting the application, the changes won&#39;t be reflected. So I added an option to disable caching of the dependencies for use in development.

However, apparently `BundleTables` caches the URL *even if the bundle collection has changed*. For example, in my own code when I want to re-create a bundle I do something like this:

    // remove an existing bundle
    BundleTable.Bundles.Remove(BundleTable.Bundles.GetBundleFor(bundleAlias));
   
    // recreate it.
    var bundle = new ScriptBundle(bundleAlias);
    
    // dependencies is a collection of objects representing scripts, 
    // this creates a new bundle from that list. 

    foreach (var item in dependencies)
    {
        bundle.Include(item.Path);
    }

    // add the new bundle to the collection

    BundleTable.Bundles.Add(bundle);

    // bundleAlias is the same alias used previously to create the bundle,
    // like &quot;~/mybundle1&quot; 
   
    var bundleUrl = BundleTable.Bundles.ResolveBundleUrl(bundleAlias);

    // returns something like &quot;/mybundle1?v=hzBkDmqVAC8R_Nme4OYZ5qoq5fLBIhAGguKa28lYLfQ1&quot;


Whenever I remove &amp; recreate a bundle *with the same alias*, absolutely nothing happens: the `bundleUrl` returned from `ResolveBundleUrl` is the same as before I removed &amp; recreated the bundle. By &quot;the same&quot; I mean that the content hash is unchanged to reflect the new contents of the bundle. 

*edit*... actually, it&#39;s much worse than that. The *bundle itself* is cached somehow outside of the `Bundles` collection. If I just generate my own random hash to prevent the browser from caching the script, ASP.NET returns *the old script*. So, apparently, removing a bundle from `BundleTable.Bundles` does not actually do anything. 

I can simply change the alias to get around this problem, and that is OK for development, but I don&#39;t like that idea since it means either I have to deprecate aliases after each page load, or have a BundleCollection that grows in size on every page load. If you left this on in a production environment, it would be a disaster.

So it seems that when a script is served, it gets cached independent of the actual `BundleTables.Bundles` object. So if you re-use a URL, even if you&#39;ve removed the bundle that it referred to before reusing it, it responds with whatever&#39;s in its cache, and altering the `Bundles` object does not flush the cache -- so only *new* items (or rather, new items with a different name) would ever be used.

The behavior seems odd... removing something from the collection should remove it from the cache. But it doesn&#39;t. There must be a way to flush this cache and have it use the current contents of the `BundleCollection` instead of what it cached when that bundle was first accessed. 

Any idea how I would do this?

There is this `ResetAll` method which has an unknown purpose but it just breaks things anyway so that isn&#39;t it.

How to force BundleCollection to flush cached script bundles in MVC4

I tried this code:

    private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
    {
        if (Convert.ToInt32(e.KeyChar) == 13) 
        {
            MessageBox.Show(&quot; Enter pressed &quot;);
        }
    }



and this:

    private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
    {
        if (e.KeyChar == Convert.ToChar(Keys.Enter))
        {
            MessageBox.Show(&quot; Enter pressed &quot;);
        }
    }

and this:

    private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
    {
        if (e.KeyChar == Keys.Enter)
        {
            MessageBox.Show(&quot; Enter pressed &quot;);
        }
    }

but they&#39;re not working...

When I write something and press &lt;kbd&gt;Enter&lt;/kbd&gt;, it doesn&#39;t work. It only highlights my text.

Enter key press in C#

I want to list every file and directory contained in a directory and subdirectories of that directory. If I chose C:\ as the directory, the program would get every name of every file and folder on the hard drive that it had access to.

A list might look like

&lt;pre&gt;
fd\1.txt
fd\2.txt
fd\a\
fd\b\
fd\a\1.txt
fd\a\2.txt
fd\a\a\
fd\a\b\
fd\b\1.txt
fd\b\2.txt
fd\b\a
fd\b\b
fd\a\a\1.txt
fd\a\a\a\
fd\a\b\1.txt
fd\a\b\a
fd\b\a\1.txt
fd\b\a\a\
fd\b\b\1.txt
fd\b\b\a
&lt;/pre&gt;

List all files and directories in a directory + subdirectories

Today I installed the .NET Framework 4.5 on my machine expecting to be able to use it from Visual Studio 2010, since it&#39;s just a minor update that should&#39;t pose problems for Visual&amp;nbsp;Studio&amp;nbsp;2010. Unfortunately I am not, even manually removing certain 4.0 and adding the corresponding 4.5 assemblies resulted in the original 4.0 assemblies still being referenced in the project.

Is it possible to target version 4.5 from Visual&amp;nbsp;Studio&amp;nbsp;2010 and if yes, how? I&#39;d really like to use the ribbons...


Targeting .NET Framework 4.5 via Visual Studio 2010

How to remove empty lines in Visual Studio?

Remove empty lines in text using Visual Studio or VS Code

I have a solution with 10+ projects (VS2010 SP1). I have the following configurations defined in the solution:

 - Debug
 - Debug-QA
 - Release-UAT
 - Release-Production

This allows me to easily setup specific settings for each deployment scenario. However, for some reason I can&#39;t get things setup as I&#39;d like. Please see this screenshot:

![Screenshot of Configuration Manager][1]

Notice the highlighted projects/configurations. I am unable to create a &quot;Debug-QA&quot; configuration for these projects (by selecting `&lt;New&gt;` in the cell for that particular project). When I try to add a new &quot;Debug-QA&quot; configuration to the DataUtility project, for instance, Visual Studio yells at me:

&gt; This configuration could not be created because a solution configuration of the same name already exists.

I know it does! I&#39;m trying to add the configuration to the project! What am I missing here? I want all projects to have all 5 configuration. I have the same problem when trying to match up (create) platforms (for instance, adding an &quot;Any CPU&quot; platform to the DataUtility project).

  [1]: http://i.stack.imgur.com/uP8wX.png

Configuration With Same Name Already Exists

I use Visual Studio 2010 C++ and my project builds without errors but when I run it I get this. I am on Windows XP.



    &#39;Shaders.exe&#39;: Loaded &#39;C:\Documents and Settings\User\My Documents\Visual Studio        2010\Projects\Shaders\Win32\Debug\Shaders.exe&#39;, Symbols loaded.
    &#39;Shaders.exe&#39;: Loaded &#39;C:\WINDOWS\system32\ntdll.dll&#39;, Cannot find or open the PDB file
    &#39;Shaders.exe&#39;: Loaded &#39;C:\WINDOWS\system32\kernel32.dll&#39;, Cannot find or open the PDB  file
    &#39;Shaders.exe&#39;: Loaded &#39;C:\qt-everywhere-opensource-src-4.8.3\bin\QtCored4.dll&#39;, Symbols  loaded.
    &#39;Shaders.exe&#39;: Loaded &#39;C:\WINDOWS\system32\user32.dll&#39;, Cannot find or open the PDB file
    &#39;Shaders.exe&#39;: Loaded &#39;C:\WINDOWS\system32\gdi32.dll&#39;, Cannot find or open the PDB file
    &#39;Shaders.exe&#39;: Loaded &#39;C:\WINDOWS\system32\ole32.dll&#39;, Cannot find or open the PDB file
    &#39;Shaders.exe&#39;: Loaded &#39;C:\WINDOWS\system32\advapi32.dll&#39;, Cannot find or open the PDB file
    &#39;Shaders.exe&#39;: Loaded &#39;C:\WINDOWS\system32\rpcrt4.dll&#39;, Cannot find or open the PDB file
    &#39;Shaders.exe&#39;: Loaded &#39;C:\WINDOWS\system32\secur32.dll&#39;, Cannot find or open the PDB file
    &#39;Shaders.exe&#39;: Loaded &#39;C:\WINDOWS\system32\msvcrt.dll&#39;, Cannot find or open the PDB file
    &#39;Shaders.exe&#39;: Loaded &#39;C:\WINDOWS\system32\ws2_32.dll&#39;, Cannot find or open the PDB file
    &#39;Shaders.exe&#39;: Loaded &#39;C:\WINDOWS\system32\ws2help.dll&#39;, Cannot find or open the PDB file
    &#39;Shaders.exe&#39;: Loaded &#39;C:\WINDOWS\system32\msvcp100d.dll&#39;, Symbols loaded.
    &#39;Shaders.exe&#39;: Loaded &#39;C:\WINDOWS\system32\msvcr100d.dll&#39;, Symbols loaded.
    &#39;Shaders.exe&#39;: Loaded &#39;C:\qt-everywhere-opensource-src-4.8.3\bin\QtGuid4.dll&#39;, Symbols loaded.
    &#39;Shaders.exe&#39;: Loaded &#39;C:\WINDOWS\system32\comdlg32.dll&#39;, Cannot find or open the PDB file
    &#39;Shaders.exe&#39;: Loaded &#39;C:\WINDOWS\system32\comctl32.dll&#39;, Cannot find or open the PDB file
    &#39;Shaders.exe&#39;: Loaded &#39;C:\WINDOWS\system32\shell32.dll&#39;, Cannot find or open the PDB file
    &#39;Shaders.exe&#39;: Loaded &#39;C:\WINDOWS\system32\shlwapi.dll&#39;, Cannot find or open the PDB file
    &#39;Shaders.exe&#39;: Loaded &#39;C:\WINDOWS\system32\oleaut32.dll&#39;, Cannot find or open the PDB file
    &#39;Shaders.exe&#39;: Loaded &#39;C:\WINDOWS\system32\imm32.dll&#39;, Cannot find or open the PDB file
    &#39;Shaders.exe&#39;: Loaded &#39;C:\WINDOWS\system32\winmm.dll&#39;, Cannot find or open the PDB file
    &#39;Shaders.exe&#39;: Loaded &#39;C:\WINDOWS\system32\winspool.drv&#39;, Cannot find or open the PDB file
    &#39;Shaders.exe&#39;: Loaded &#39;C:\qt-everywhere-opensource-src-4.8.3\bin\QtOpenGLd4.dll&#39;, Symbols loaded.
   


Thanks

Cannot find or open the PDB file in Visual Studio C++ 2010

Periodically I am getting the following exception:

`Unable to load DLL &#39;SQLite.Interop.dll&#39;: The specified module could not be found. (Exception from HRESULT: 0x8007007E)`

I am using 1.0.82.0. version, installing it with nuget in VS2010, OS Win7 64.

Once exception starts to appear, it appears constantly - in debug and release and running application within or outside VS.

The only way to stop it is logoff and logon. The exception is not thrown and dll is loaded.
It can work for days, but then it can break again. 

Has anyone seen something like this and is there a solution for it?




Unable to load DLL &#39;SQLite.Interop.dll&#39;

Is it possible to use try catch block inside of a lambda function.  I need the lambda function to convert a certain variable into an integer, but not all of the values will be able to be converted into integers.

Python Try Catch Block inside lambda

**EDITED:**

How can I set a Django field&#39;s default to a function that gets evaluated each time a new model object gets created?  

I want to do something like the following, except that in this code, the code gets evaluated once and sets the default to the same date for each model object created, rather than evaluating the code each time a model object gets created:

    from datetime import datetime, timedelta
    class MyModel(models.Model):
      # default to 1 day from now
      my_date = models.DateTimeField(default=datetime.now() + timedelta(days=1))

&lt;br/&gt;
&lt;br/&gt;

**ORIGINAL:**

I want to create a default value for a function parameter such that it is dynamic and gets called and set each time the function is called.  How can I do that?  e.g.,

    from datetime import datetime
    def mydate(date=datetime.now()):
      print date
    
    mydate() 
    mydate() # prints the same thing as the previous call; but I want it to be a newer value

Specifically, I want to do it in Django, e.g.,

    from datetime import datetime, timedelta
    class MyModel(models.Model):
      # default to 1 day from now
      my_date = models.DateTimeField(default=datetime.now() + timedelta(days=1))



How to set a Django model field&#39;s default value to a function call / callable (e.g., a date relative to the time of model object creation)

I was writing some lambda functions and couldn&#39;t figure this out. Is there a way to have something like `lambda x: x if (x&lt;3)` in python? As `lambda a,b: a if (a &gt; b) else b` works ok. So far `lambda x: x &lt; 3 and x or None` seems to be the closest i have found.

Python lambda with if but without else

I have some list&lt;T&gt; (where T is a custom class, and class has some properties).
I would like to know how to change one or more values inside of it by using Lambda Expressions, so the result will be the same as the foreach loop bellow:


*NOTE: list&lt;T&gt; contains multiple items inside (multiple rows)*

            foreach (MyClass mc in list)  
            {
                if (mc.Name == &quot;height&quot;)
                    mc.Value = 30;
            }

 
And this the the linq query (using Lambda expressions), but its not the same as the upper foreach loop, it only returns 1 item (one row) from the list!

What I want is, that it returns all the items (all rows) and ONLY changes the appropriate one (the items specified in the WHERE extension method(s).

    list = list.Where(w =&gt; w.Name == &quot;height&quot;).Select(s =&gt; { s.Value = 30; return s; }).ToList();

NOTE: these 2 example are not the same! I repeat, the linq only returns 1 item (one row), and this is something I don&#39;t want, I need all items from the list as well (like foreach loop, it only do changes, but it does not remove any item).


Change some value inside the List&lt;T&gt;

Basically, what I want to be able to do is take a lambda with any number of any type of parameters and convert it to an std::function.
I&#39;ve tried the following and neither method works.

    std::function([](){});//Complains that std::function is missing template parameters
    template &lt;typename T&gt; void foo(function&lt;T&gt; f){}
    foo([](){});//Complains that it cannot find a matching candidate

The following code does work however, but it is not what I want because it requires explicitly stating the template parameters which does not work for generic code.

    std::function&lt;void()&gt;([](){});

I&#39;ve been mucking around with functions and templates all evening and I just can&#39;t figure this out, so any help would be much appreciated.

As mentioned in a comment, the reason I&#39;m trying to do this is because I&#39;m trying to implement currying in C++ using variadic templates. Unfortunately, this fails horribly when using lambdas. For example, I can pass a standard function using a function pointer.

    template &lt;typename R, typename...A&gt;
    void foo(R (*f)(A...)) {}
    void bar() {}
    int main() {
        foo(bar);
    }

However, I can&#39;t figure out how to pass a lambda to such a variadic function. Why I&#39;m interested in converting a generic lambda into an std::function is because I can do the following, but it ends up requiring that I explicitly state the template parameters to std::function which is what I am trying to avoid.

    template &lt;typename R, typename...A&gt;
    void foo(std::function&lt;R(A...)&gt;) {}
    int main() {
        foo(std::function&lt;void()&gt;([](){}));
    }
    

How to convert a lambda to an std::function using templates

There&#39;s something I don&#39;t understand about anonymous functions using the short notation #(..)

The following works:

    REPL&gt;  ((fn [s] s) &quot;Eh&quot;)
    &quot;Eh&quot;

But this doesn&#39;t:

    REPL&gt;  (#(%) &quot;Eh&quot;)

This works:

    REPL&gt; (#(str %) &quot;Eh&quot;)
    &quot;Eh&quot;

What I don&#39;t understand is why *(#(%) &quot;Eh&quot;)* doesn&#39;t work and at the same time I don&#39;t need to use *str* in *((fn [s] s) &quot;Eh&quot;)*

They&#39;re both anonymous functions and they both take, here, one parameter.  Why does the shorthand notation need a function while the other notation doesn&#39;t?



Anonymous function shorthand

We have two different way for doing function expression in JavaScript:

**Named function expression (NFE)**: 

    var boo = function boo () {
      alert(1);
    };

**Anonymous function expression**:

    var boo = function () {
      alert(1);
    };

And both of them can be called with `boo();`. I really can&#39;t see why/when I should use anonymous functions and when I should use Named Function Expressions. What difference is there between them?

Why use named function expressions?

Considering the following code snippet:

    # directorys == {&#39;login&#39;: &lt;object at ...&gt;, &#39;home&#39;: &lt;object at ...&gt;}
    for d in directorys:
        self.command[&quot;cd &quot; + d] = (lambda : self.root.change_directory(d))

I expect to create a dictionary of two function as following :

    # Expected :
    self.command == {
        &quot;cd login&quot;: lambda: self.root.change_directory(&quot;login&quot;),
        &quot;cd home&quot;: lambda: self.root.change_directory(&quot;home&quot;)
    }

but it looks like the two lambda function generated are exactly the same :

    # Result :
    self.command == {
        &quot;cd login&quot;: lambda: self.root.change_directory(&quot;login&quot;),
        &quot;cd home&quot;: lambda: self.root.change_directory(&quot;login&quot;)   # &lt;- Why login ?
    }

I really don&#39;t understand why. Do you have any suggestions ?

Lambda in a loop

    function foo(x) {
       console.log(arguments)
    } //foo(1) prints [1]

but 

    var bar = x =&gt; console.log(arguments) 

gives the following error when invoked in the same way:

    Uncaught ReferenceError: arguments is not defined

Content Type	Original Author	Original Content on Stackoverflow
Question	Steven Jeuris	View Question on Stackoverflow
Solution 1 - C#	Martin Ernst	View Answer on Stackoverflow

Is it possible to set a breakpoint in anonymous functions?

C# Problem Overview

C# Solutions

Solution 1 - C#

How to delete all files from a specific folder?

What will the version be when I don't specify it in the Maven's pom.xml?

Attributions