The value of `rectangle` is being boxed - but then you&#39;re losing the boxed value, which is what&#39;s being modified. Try this:

    Rectangle rectangle = new Rectangle();
    PropertyInfo propertyInfo = typeof(Rectangle).GetProperty(&quot;Height&quot;);
    object boxed = rectangle;
    propertyInfo.SetValue(boxed, 5, null);
    rectangle = (Rectangle) boxed;

Ever heard of [`SetValueDirect`](http://msdn.microsoft.com/en-us/library/system.reflection.fieldinfo.setvaluedirect.aspx)? There&#39;s a reason they made it. :)

	struct MyStruct { public int Field; }
	
	static class Program
	{
		static void Main()
		{
			var s = new MyStruct();
			s.GetType().GetField(&quot;Field&quot;).SetValueDirect(__makeref(s), 5);
			System.Console.WriteLine(s.Field); //Prints 5
		}
	}

There&#39;s other methods than the undocumented `__makeref` which you could use (see `System.TypedReference`) but they&#39;re more painful.

so--i switched on &quot;color misaligned images&quot; to improve drawing performance in our app. The documentation states: 

&gt; Puts a magenta overlay over images
&gt; whose source pixels aren&#39;t aligned to
&gt; destination pixels

I don&#39;t know what the yellow means however. (There is a &quot;Color Offscreen-Rendered&quot; option that uses yellow... does &quot;Color Misaligned Images&quot; also turn on this option?)

Anybody know?

TIA

What does yellow tinting represent when using &quot;color misaligned images&quot; on iPhone/iOS

I&#39;ve written a few GUI&#39;s using Swing and I know about MVC, but I never found a good way to really organize my code somehow. What I am looking for is something like the folder structure that maven introduces for each new project. Another example is rails, where MVC is introduced through the folder structure automatically. Is there something similar for Swing?

It would also be nice to see a book that describes the development of a larger Swing Application. All I find are books about design-guidelines where design refers to the look of the application. Other Swing books (like O&#39;Reilly) describe in detail all the swing components, but where is any information about the big picture?

Are there any good examples of a swing gui, where you&#39;d say &quot;That&#39;s how you organize code/folders/packages for swing!&quot;?

EDIT: I found the following site http://www.ibm.com/developerworks/java/tutorials/j-springswing/section7.html which describes the usage of spring while creating a GUI. It is a quite old example and it doesn&#39;t answer my question, but it is a step into the right direction. It also mentions Spring RCP, but I&#39;m not sure if it could be the solution.

EDIT2: I still didn&#39;t find any better answers. Does anybody know an example for a ideally structured Swing GUI which is Open Source? Does anybody know a book, which describes it? And if not for Swing, then maybe for GUI&#39;s in general?

How to organize a Swing GUI application?

I&#39;m trying to write some code that sets a property on a struct (important that it&#39;s a property on a struct) and it&#39;s failing:

    System.Drawing.Rectangle rectangle = new System.Drawing.Rectangle();
    PropertyInfo propertyInfo = typeof(System.Drawing.Rectangle).GetProperty(&quot;Height&quot;);
    propertyInfo.SetValue(rectangle, 5, null);

The Height value (as reported by the debugger) never gets set to anything - it stays at the default value of 0.

I have done plenty of reflection on classes before and this has worked fine.  Also, I know that when dealing with structs, you need to use FieldInfo.SetValueDirect if setting a field, but I don&#39;t know of an equivalent for PropertyInfo.

Is there a way to set properties on struct instances using reflection?

I'm trying to write some code that sets a property on a struct (important that it's a property on a struct) and it's failing:
<pre><code class="hljs language-ini">System.Drawing.Rectangle rectangle = new System.Drawing.Rectangle();
PropertyInfo propertyInfo = typeof(System.Drawing.Rectangle).GetProperty("Height");
propertyInfo.SetValue(rectangle, 5, null);
</code></pre>
The Height value (as reported by the debugger) never gets set to anything - it stays at the default value of 0.
I have done plenty of reflection on classes before and this has worked fine. Also, I know that when dealing with structs, you need to use FieldInfo.SetValueDirect if setting a field, but I don't know of an equivalent for PropertyInfo.

I was simply trying to use the `DateTime` structure to transform an integer between 1 and 12 into an abbrieviated month name.

Here is what I tried:

    DateTime getMonth = DateTime.ParseExact(Month.ToString(), 
                           &quot;M&quot;, CultureInfo.CurrentCulture);
    return getMonth.ToString(&quot;MMM&quot;);

However I get a `FormatException` on the first line because the string is not a valid `DateTime`. Can anyone tell me how to do this?

Convert month int to month name

I have a very simple Windows Forms Application. And, in Windows (or, atleast Windows Forms Applications), when you press Enter while inside a Single-line TextBox Control, you hear a Ding. It&#39;s an unpleasent sound, that indicated you cannot enter a newline, because it is a single-line TextBox.

This is all fine. However, in my Form, I have 1 TextBox, and a Search Button. And I am allowing the user to Perform a search by pressing Enter after they&#39;ve finished typing, so they don&#39;t *have* to use the mouse to click the Search Button.

But this Ding sound occurs. It&#39;s very annoying.

How can we make it so just that sound doesn&#39;t play at all in my Form?

@David H - Here&#39;s how I&#39;m detecting the enter pressing:

    private void textBox1_KeyUp(object sender, KeyEventArgs e)
    {
        if (e.KeyCode == Keys.Enter)
        {
            // Perform search now.
        }
    }

Stop the &#39;Ding&#39; when pressing Enter

I stumbled upon this code:

    static void Main()
    {
        typeof(string).GetField(&quot;Empty&quot;).SetValue(null, &quot;evil&quot;);//from DailyWTF
    
        Console.WriteLine(String.Empty);//check

        //how does it behave?
        if (&quot;evil&quot; == String.Empty) Console.WriteLine(&quot;equal&quot;); 

        //output: 
        //evil 
        //equal

     }

and I wonder how is it even possible to compile this piece of code. My reasoning is:

According to MSDN `String.Empty` is read-only therefore changing it should be impossible and compiling should end with &quot;A static readonly field cannot be assigned to&quot; or similar error.

I thought Base Class Library assemblies are somehow protected and signed and whatnot to prevent exactly this kind of attack. Next time someone may change System.Security.Cryptography or another critical class.

I thought Base Class Library assemblies are compiled by NGEN after .NET installation therefore changing fields of String class should require advanced hacking and be much harder.

And yet this code compiles and works. Can somebody please explain what is wrong with my reasoning?



What are the implications of asking Reflection APIs to overwrite System.String.Empty?

I have a text box and I want to display a C# object in it in a human-readable way, just for debugging reasons. I don&#39;t want to use external libraries if possible. How do I do this?

A way to pretty print a C# object

Is there a way in C# to see if a string is Base 64 encoded other than just trying to convert it and see if there is an error?  I have code code like this:
    
    // Convert base64-encoded hash value into a byte array.
    byte[] HashBytes = Convert.FromBase64String(Value);

I want to avoid the &quot;Invalid character in a Base-64 string&quot; exception that happens if the value is not valid base 64 string. I want to just check and return false instead of handling an exception because I expect that sometimes this value is not going to be a base 64 string.  Is there some way to check before using the Convert.FromBase64String function?

Thanks!  

**Update:**  
Thanks for all of your answers.  Here is an extension method you can all use so far it seems to make sure your string will pass Convert.FromBase64String without an exception.  .NET seems to ignore all trailing and ending spaces when converting to base 64 so &quot;1234&quot; is valid and so is &quot; 1234     &quot;

    public static bool IsBase64String(this string s)
    {
        s = s.Trim();
        return (s.Length % 4 == 0) &amp;&amp; Regex.IsMatch(s, @&quot;^[a-zA-Z0-9\+/]*={0,3}$&quot;, RegexOptions.None);
    
    }

For those wondering about performance of testing vs catching and exception, in most cases for this base 64 thing it is faster to check than to catch the exception until you reach a certain length. The smaller the length faster it is

In my very unscientific testing:
For 10000 iterations for character length 100,000 - 110000 it was 2.7 times faster to test first.  

For 1000 iterations for characters length 1 - 16 characters for total of 16,000 tests it was 10.9 times faster.

I am sure there is a point where it becomes better to test with the exception based method. I just don&#39;t know at what point that is.

How to check for a valid Base64 encoded string

having a rough time working with struct fields using `reflect` package.  in particular, have not figured out how to set the field value.

&lt;pre&gt;
type t struct { fi int; fs string }
var r t = t{ 123, &quot;jblow&quot; }
var i64 int64 = 456
&lt;/pre&gt;

1. getting Name of field i - this seems to work

  `var field = reflect.TypeOf(r).Field(i).Name`

2. getting value of field i as a) interface{}, b) int - this seems to work

  `var iface interface{} = reflect.ValueOf(r).Field(i).Interface()`

  `var i int = int(reflect.ValueOf(r).Field(i).Int())`

3. setting value of field i - try one - panic

  `reflect.ValueOf(r).Field(i).SetInt( i64 )`

  _panic_: reflect.Value&#183;SetInt using value obtained using unexported field

  assuming it did not like field names &quot;id&quot; and &quot;name&quot;, so renamed to &quot;Id&quot; and &quot;Name&quot;

  a) is this assumption correct?

  b) if correct, thought not necessary since in same file / package

4. setting value of field i - try two (with field names capitalized ) - panic

  `reflect.ValueOf(r).Field(i).SetInt( 465 )`
 
  `reflect.ValueOf(r).Field(i).SetInt( i64 )`

   _panic_: reflect.Value&#183;SetInt using unaddressable value

&lt;hr /&gt;

Instructions below by @peterSO are thorough and high quality

Four. this works:

  `reflect.ValueOf(&amp;r).Elem().Field(i).SetInt( i64 )`

he documents as well that the field names must be exportable (begin with capital letter)

Using reflect, how do you set the value of a struct field?

I am trying to perform a backup/restore function for static properties of classes. I can get a list of all of the static properties and their values using the reflection objects `getStaticProperties()` method. This gets both `private` and `public static` properties and their values.

The problem is I do not seem to get the same result when trying to restore the properties with the reflection objects `setStaticPropertyValue($key, $value)` method. `private` and `protected` variables are not visible to this method as they are to `getStaticProperties()`. Seems inconsistent.

Is there any way to set a private/protected static property using reflection classes, or any other way for that matter?

**TRIED**

	class Foo {
		static public $test1 = 1;
		static protected $test2 = 2;
		
		public function test () {
			echo self::$test1 . &#39;&lt;br&gt;&#39;;
			echo self::$test2 . &#39;&lt;br&gt;&lt;br&gt;&#39;;
		}
		
		public function change () {
			self::$test1 = 3;
			self::$test2 = 4;
		}
	}

	$test = new foo();
	$test-&gt;test();
	
	// Backup
	$test2 = new ReflectionObject($test);
	$backup = $test2-&gt;getStaticProperties();
	
	$test-&gt;change();
	
	// Restore
	foreach ($backup as $key =&gt; $value) {
		$property = $test2-&gt;getProperty($key);
		$property-&gt;setAccessible(true);
		$test2-&gt;setStaticPropertyValue($key, $value);
	}
	
	$test-&gt;test();

Is there any way to set a private/protected static property using reflection classes?

I have a class:

    class TestClass
      def method1
      end
  
      def method2
      end
 
      def method3
      end
    end

How can I get a list of my methods in this class (`method1`, `method2`, `method3`)?

Get list of a class&#39; instance methods

How can I programmatically get the current product version in C#? 

My code:

    VersionNumber = System.Reflection.Assembly.GetExecutingAssembly().GetName().Version.ToString();

I am getting VersionNumber=1.0.0.0, but the current version is 1.0.0.12.



How to get the current product version in C#?

I have a class, lets call it Book with a property called Name. With that property, I have an attribute associated with it.

    public class Book
    {
        [Author(&quot;AuthorName&quot;)]
        public string Name
        {
            get; private set; 
        }
    }

In my main method, I&#39;m using reflection and wish to get key value pair of each attribute for each property. So in this example, I&#39;d expect to see &quot;Author&quot; for attribute name and &quot;AuthorName&quot; for the attribute value.

Question: How do I get the attribute name and value on my properties using Reflection?



Content Type	Original Author	Original Content on Stackoverflow
Question	Victor Chelaru	View Question on Stackoverflow
Solution 1 - C#	Jon Skeet	View Answer on Stackoverflow
Solution 2 - C#	user541686	View Answer on Stackoverflow

Is there a way to set properties on struct instances using reflection?

C# Problem Overview

C# Solutions

Solution 1 - C#

Solution 2 - C#

How to organize a Swing GUI application?

What does yellow tinting represent when using "color misaligned images" on iPhone/iOS

Attributions