In general, you *shouldn&#39;t* do this - if a type has been marked internal, that means you&#39;re not meant to use it from outside the assembly. It could be removed, changed etc in a later version.

However, reflection *does* allow you to access types and members which aren&#39;t public - just look for overloads which take a `BindingFlags` argument, and include `BindingFlags.NonPublic` in the flags that you pass.

If you have the *fully qualified* name of the type (including the assembly information) then just calling [`Type.GetType(string)`][1] should work. If you know the assembly in advance, and know of a public type within that assembly, then using `typeof(TheOtherType).Assembly` to get the assembly reference is generally simpler, then you can call [`Assembly.GetType(string)`][2].


  [1]: http://msdn.microsoft.com/en-us/library/w3f99sx1.aspx
  [2]: http://msdn.microsoft.com/en-us/library/y0cd10tb.aspx

To load the assembly and type you quoted in your example:

    Assembly design = Assembly.LoadFile(@&quot;C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\System.Design.dll&quot;);
    Type designHost = design.GetType(&quot;System.ComponentModel.Design.DesignerHost&quot;);


Is there any way to replace a regexp with modified content of capture group?

Example:

    Pattern regex = Pattern.compile(&quot;(\\d{1,2})&quot;);
    Matcher regexMatcher = regex.matcher(text);
    resultString = regexMatcher.replaceAll(&quot;$1&quot;); // *3 ??

And I&#39;d like to replace all occurrence with $1 multiplied by 3.

**edit:**

Looks like, something&#39;s wrong :(

If I use

    Pattern regex = Pattern.compile(&quot;(\\d{1,2})&quot;);
    Matcher regexMatcher = regex.matcher(&quot;12 54 1 65&quot;);
    try {
        String resultString = regexMatcher.replaceAll(regexMatcher.group(1));
    } catch (Exception e) {
        e.printStackTrace();
    }

It throws an IllegalStateException: No match found

But

    Pattern regex = Pattern.compile(&quot;(\\d{1,2})&quot;);
    Matcher regexMatcher = regex.matcher(&quot;12 54 1 65&quot;);
    try {
        String resultString = regexMatcher.replaceAll(&quot;$1&quot;);
    } catch (Exception e) {
        e.printStackTrace();
    }

works fine, but I can&#39;t change the $1 :(

**edit:**

Now, it&#39;s working :)

Java Regex Replace with Capturing Group

We now have the &quot;dot&quot; notation for properties.  I&#39;ve seen various [back][1] and [forths][2] about the merits of dot notation vs. message notation.  To keep the responses untainted I&#39;m not going to respond either way in the question.

What is your thought about dot notation vs. message notation for property accessing?  

Please try to keep it focused on Objective-C - my one bias I&#39;ll put forth is that Objective-C is Objective-C, so your preference that it be like Java or JavaScript aren&#39;t valid.

Valid commentary is to do with technical issues (operation ordering, cast precedence, performance, etc), clarity (structure vs. object nature, both pro and con!), succinctness, etc.

Note, I&#39;m of the school of rigorous quality and readability in code having worked on huge projects where code convention and quality is paramount (the write once read a thousand times paradigm).


  [1]: http://iphonedevelopment.blogspot.com/2009/08/dot-notation-controversy.html
  [2]: http://weblog.bignerdranch.com/?p=83

Dot notation vs. message notation for declared properties

How can I access an internal class of an assembly?
Say I want to access System.ComponentModel.Design.DesignerHost. Here the DesignerHost is an internal and sealed class. 

How can I write a code to load the assembly and the type?.

How to access internal class using Reflection

<p>How can I access an internal class of an assembly?
Say I want to access System.ComponentModel.Design.DesignerHost. Here the DesignerHost is an internal and sealed class.</p>
<p>How can I write a code to load the assembly and the type?.</p>


is it possible to store list to session variable in Asp.net C# ?

Store List to session

I want to execute this stored procedure from a C# program.

I have written the following stored procedure in a SqlServer query window and saved it as 
stored1:
     
    use master 
    go
    create procedure dbo.test as

    DECLARE @command as varchar(1000), @i int
    SET @i = 0
    WHILE @i &lt; 5
    BEGIN
    Print &#39;I VALUE &#39; +CONVERT(varchar(20),@i)
    EXEC(@command)
    SET @i = @i + 1
    END

&lt;b&gt;EDITED:&lt;/b&gt;
       
    using System;
    using System.Collections.Generic;
    using System.Text;
    using System.Data;
    using System.Data.SqlClient;
    namespace AutomationApp
    {
        class Program
        {
            public void RunStoredProc()
            {
                SqlConnection conn = null;
                SqlDataReader rdr  = null;

                Console.WriteLine(&quot;\nTop 10 Most Expensive Products:\n&quot;);

                try
                {
                    conn = new SqlConnection(&quot;Server=(local);DataBase=master;Integrated Security=SSPI&quot;);
                    conn.Open();
                    SqlCommand cmd = new SqlCommand(&quot;dbo.test&quot;, conn);
                    cmd.CommandType = CommandType.StoredProcedure;
                    rdr = cmd.ExecuteReader();
                    /*while (rdr.Read())
                    {
                        Console.WriteLine(
                            &quot;Product: {0,-25} Price: ${1,6:####.00}&quot;,
                            rdr[&quot;TenMostExpensiveProducts&quot;],
                            rdr[&quot;UnitPrice&quot;]);
                    }*/
                }
                finally
                {
                    if (conn != null)
                    {
                        conn.Close();
                    }
                    if (rdr != null)
                    {
                        rdr.Close();
                    }
                }
            }
            static void Main(string[] args)
            {
                Console.WriteLine(&quot;Hello World&quot;);
                Program p= new Program();
                p.RunStoredProc();		
                Console.Read();
            }
        }
    }

This displays the exception `Cannot find the stored procedure dbo.test`. Do I need to provide the path? If yes, in which location should the stored procedures be stored?

How to execute a stored procedure within C# program

Is there a quick way to find all of the implementations of, not references to, an interface&#39;s method/property/etc?  Here&#39;s some sample code: 

    public class SomeClass : IBaseClass
    {
      public Int32 GetInt()
      {
         return 1;
      }
    }
    
    public interface IBaseClass
    {
      public Int32 GetInt();
    }
    
    public class SomeOtherClass
    {
      IBaseClass _someClass;
      private TestMethod()
      {
        _someClass = new SomeClass();
        _someClass.GetInt();
      }
    }

I want to quickly get to SomeClass.GetInt() while reviewing SomeOtherClass.TestMethod().  If I right click on _someClass.GetInt() and click &#39;Go To Definition&#39;, it takes me to the interface.  If I click &#39;Find All References&#39;, I could potentially see a list of all uses ... not just the classes that implement the GetInt() method.  

Is there a faster way to find this?  Any tips from other developers?  We are using D.I. for most of our dependencies, which means that tracing through deeply nested code takes *forever*.

How do you quickly find the implementation(s) of an interface&#39;s method?

How do you display a custom [`UserControl`][1] as a dialog in C#/WPF (.NET 3.5)?


  [1]: http://msdn.microsoft.com/en-us/library/system.windows.controls.usercontrol.aspx

How do you display a custom UserControl as a dialog?

Given a text file, how would I go about reading an arbitrary line and nothing else in the file?

Say, I have a file test.txt.  How would I go about reading line number 15 in the file?

All I&#39;ve seen is stuff involving storing the entire text file as a String array and then using the value of the line number as the number of the String to use from the array... but there are some complications: The text file is enormously huge and the machine that the application I&#39;m coding isn&#39;t exactly a top-notch system. Speed isn&#39;t the top priority, but it is definitely a major issue.

Are there any ways to **ONLY** read a specific line of a text file and store the result as a string?


Thanks for your responses:
The file is KINDA structured. It&#39;s got 25 lines of info and then *X* lines of numbers but line 17 of the first 25 has the value of *X*.

But then, there&#39;s 1 blank line and it repeats itself all over as a second record in the file and *X* can have a different value for each record.

What I want to do is read and store the first 25 lines as independent values and then store the next *X* (usually around 250) lines as an array. Then I&#39;m going to store it in an SQL database and repeat with the NEXT record until I reach the *Y*th record (the number of records in the file is in line 3)

**EDIT 2**:
Alright, I think I&#39;ve gotten to a solution based on a combination of your alls&#39; responses.

I&#39;m going to read the first 25 lines and store it as an array. I&#39;ll copy the pertinent contents of the array to local variables then I&#39;ll delete the first 25 lines. Then, I can use the info to store the next *X* lines (the value of item 13 in the array) as an array, serialize it, store it in a database then delete the lines that I just read.

I could then repeat the process for each subsequent record.

Of course, this relies on one assumption I&#39;m making, which to be honest, I&#39;m not sure is true. Is it possible to delete the first *n* lines from a text file from within C# without having to read the entire thing and re-write it without the first *n* lines?

How do I read a specified line in a text file?

How do you get a collection of all the types that inherit from a specific other type?

How to find all the types in an Assembly that Inherit from a Specific Type C#

I&#39;ve always avoided Java reflection soley based on its reputation for slowness. I reached a point in the design of my current project where being able to use it would make my code much more readable and elegant, so I decided to give it a go. 

I was simply astonished by the difference, I noticed at times almost 100x longer run times. Even in this simple example where it just instantiates an empty class, it&#39;s unbelievable.

    class B {
    	
    }
    
    public class Test {
    	
    	public static long timeDiff(long old) {
    		return System.currentTimeMillis() - old;
    	}
    	
    	public static void main(String args[]) throws Exception {
    		
    		long numTrials = (long) Math.pow(10, 7);
    		
    		long millis;
    		
    		millis = System.currentTimeMillis();
    		
    		for (int i=0; i&lt;numTrials; i++) {
    			new B();
    		}
    		System.out.println(&quot;Normal instaniation took: &quot;
                     + timeDiff(millis) + &quot;ms&quot;);
    		
    		millis = System.currentTimeMillis();
    		
    		Class&lt;B&gt; c = B.class;
    		
    		for (int i=0; i&lt;numTrials; i++) {
    			c.newInstance();
    		}
    		
    		System.out.println(&quot;Reflecting instantiation took:&quot; 
                  + timeDiff(millis) + &quot;ms&quot;);
    		
    	}
    }

So really, my questions are

 - Why is it this slow? Is there something I&#39;m doing wrong? (even the example above demonstrates the difference). I have a hard time believing that it can really be 100x slower than normal instantiation.

 - Is there something else that can be better used for treating code as Data (bear in mind I&#39;m stuck with Java for now)



Java Reflection: Why is it so slow?

Consider the following sample code:

    class SampleClass
    {
        public long SomeProperty { get; set; }
    }

    public void SetValue(SampleClass instance, decimal value)
    {
        // value is of type decimal, but is in reality a natural number =&gt; cast
        instance.SomeProperty = (long)value;
    }


Now I need to do something similar through reflection:

    void SetValue(PropertyInfo info, object instance, object value)
    {
        // throws System.ArgumentException: Decimal can not be converted to Int64
        info.SetValue(instance, value)  
    }

Note that I cannot assume that the PropertyInfo always represents a long, neither that value is always a decimal. However, I know that value can be casted to the correct type for that property.

How can I convert the &#39;value&#39; parameter to the type represented by PropertyInfo instance through reflection ?


&#39;casting&#39; with reflection

I want to call my generic method with a given type object.

    void Foo(Type t)
    {
         MyGenericMethod&lt;t&gt;();
    }

obviously doesn&#39;t work.

How can I make it work?


How to call generic method with a given Type object?

I need to read classes contained in a Java package. Those classes are in classpath. I need to do this task from a Java program directly. Do you know a simple way to do?

    List&lt;Class&gt; classes = readClassesFrom(&quot;my.package&quot;)

How do I read all classes from a Java package in the classpath?

Can one write something like:

    class Test(object):
        def _decorator(self, foo):
            foo()
    
        @self._decorator
        def bar(self):
            pass

This fails: self in @self is unknown

I also tried:

    @Test._decorator(self)

which also fails: Test unknown

I would like to temporarily change some instance variables 
in the decorator and then run the decorated method, before
changing them back.







Python decorators in classes

Consider the following code:

    class Base(object):
    
        @classmethod
        def do(cls, a):
            print cls, a
    
    class Derived(Base):
    
        @classmethod
        def do(cls, a):
            print &#39;In derived!&#39;
            # Base.do(cls, a) -- can&#39;t pass `cls`
            Base.do(a)
    
    if __name__ == &#39;__main__&#39;:
        d = Derived()
        d.do(&#39;hello&#39;)

    &gt; $ python play.py  
    &gt; In derived! 
    &gt; &lt;class &#39;__main__.Base&#39;&gt; msg

From `Derived.do`, how do I call `Base.do`? 

I would normally use `super` or even the base class name directly if this is a normal object method, but apparently I can&#39;t find a way to call the classmethod in the base class. 

In the above example, `Base.do(a)` prints `Base` class instead of `Derived` class.


Calling a base class&#39;s classmethod in Python

In Ruby, since you can include multiple mixins but only extend one class, it seems like mixins would be preferred over inheritance.

My question: if you&#39;re writing code which must be extended/included to be useful, why would you ever make it a class? Or put another way, why wouldn&#39;t you always make it a module?

I can only think of one reason why you&#39;d want a class, and that is if you need to instantiate the class. In the case of ActiveRecord::Base, however, you never instantiate it directly. So shouldn&#39;t it have been a module instead?

ruby inheritance vs mixins

How would you find a particular class name inside lots of jar files?

(Looking for the actual class name, not the classes that reference it.)

Find a class somewhere inside dozens of JAR files?

Is it possible in PHP to instantiate an object from the name of a class, if the class name is stored in a string?


Can PHP instantiate an object from the name of the class as a string?

With jQuery you can bind functions to an event triggered on a DOM object using `.bind()` or one of the event handler helper functions.

jQuery have to store this internally somehow and I wonder if is it possible given a DOM object, to find out which events have been bound to the object, and access those functions etc. The desired return result could look something like this:

    {
      click: [function1, function2],
      change: [function3],
      blur: [function4, function5, function6]
    }

Accessing functions bound to event handlers with jQuery

Ok, so this may be a bit of a silly question, and there&#39;s certainly the obvious answer, but I was curious if I&#39;ve missed any subtleties here.

Is there any difference in terms of visibility/usability between a `public` member declared in an `internal` class and an `internal` member declared in an `internal` class?

i.e. between

    internal class Foo
    {
        public void Bar()
        {
        }
    }

and

    internal class Foo
    {
        internal void Bar()
        {
        }
    }

If you declared the method as `public` and also `virtual`, and then overrode it in a derived class that is `public`, the reason for using this modifier is clear. However, is this the only situation... am I missing something else?

Public and Internal members in an Internal class?

I really don&#39;t get it.

If the base class is abstract and only intended to be used to provide common functionality to public subclasses defined in the assembly, why shouldn&#39;t it be declared internal?

I don&#39;t want the abstract class to be visible to code outside the assembly. I don&#39;t want external code to know about it.

Why can&#39;t my public class extend an internal class?

What is the difference between the `internal` and `private` access modifiers in C#?

Internal vs. Private Access Modifiers

Is there a way to disable restrictions of javac 1.6.0_22 that prevent me from using JRE internal classes like `sun.awt.event.*` ?

I&#39;m **not** looking for:

1. an explanation why it is forbidden.
1. suggestion to use different classes
1. suggestion to use reflection
1. suggestion to use ecj/eclipse

I just want to know if it is possible or not, and if it is then how.

Content Type	Original Author	Original Content on Stackoverflow
Question	dattebayo	View Question on Stackoverflow
Solution 1 - C#	Jon Skeet	View Answer on Stackoverflow
Solution 2 - C#	Patrick McDonald	View Answer on Stackoverflow

How to access internal class using Reflection

C# Problem Overview

C# Solutions

Solution 1 - C#

Solution 2 - C#

Dot notation vs. message notation for declared properties

Java Regex Replace with Capturing Group

Attributions