Did you try to surround your string with quotes? Maybe leading and trailing whitespaces are stripped automatically.

    &lt;string name=&quot;foo&quot;&gt;&quot; bar&quot;&lt;/string&gt;

See the example at https://developer.android.com/guide/topics/resources/string-resource.html#FormattingAndStyling in section *&quot;Escaping apostrophes and quotes&quot;*.

 As an alternative to the answer given by Andreas Kl&#246;ber you can use this method:

    &lt;string name=&quot;foobar&quot;&gt;foo \u0020 bar&lt;/string&gt;

This utilizes the unicode space character (\u0020).

Just quote the value, like this

    &lt;string name=&quot;str_name&quot;&gt;&quot; Hello World!&quot;&lt;/string&gt;


I have a User model that has a :credits attribute.   I want a simple button that will add 5 to  the user&#39;s credits, through a route called &quot;add&quot; so that /users/3/add would add 5 to the credits of user id = 3.

  

    def add
        @user = User.find(params[:id])
        @user.credits += 5
        redirect_to root_path
    end

That is the relevant part of my controller.  The problem is, I dont want to call @user.save because I have a before_save callback that re-encrypts the user&#39;s password based on the current UTC time.   I just want to simply add 5 to the attribute and avoid the callback, I never thought such a simple thing could be so hard.

EDIT:

I changed the callback to :before_create,
here is my new controller code (relevant part):

      def add
        @user = User.find(params[:id])
        @user.add_credits(5)
        @user.save
        flash[:success] = &quot;Credits added!&quot;
        redirect_to root_path
      end

and here is my code in the model:

     def add_credits(num)
        self.credits = num
     end

EDIT 2:

Ok it was a validation problem that made the changes in &quot;EDIT&quot; not work, but I&#39;d still love an answer to the original question of updating without callbacks!

Rails: Update model attribute without invoking callbacks

I&#39;m having lots of Funcy fun (fun intended) with generic methods. In most cases C# type inference is smart enough to find out what generic arguments it must use on my generic methods, but now I&#39;ve got a design where the C# compiler doesn&#39;t succeed, while I believe it could have succeeded in finding the correct types.

Can anyone tell me whether the compiler is a bit dumb in this case, or is there a very clear reason why it can&#39;t infer my generic arguments?

Here&#39;s the code:

Classes and interface definitions:

    interface IQuery&lt;TResult&gt; { }

    interface IQueryProcessor
    {
        TResult Process&lt;TQuery, TResult&gt;(TQuery query)
            where TQuery : IQuery&lt;TResult&gt;;
    }

    class SomeQuery : IQuery&lt;string&gt;
    {
    }

Some code that does not compile:

    class Test
    {
        void Test(IQueryProcessor p)
        {
            var query = new SomeQuery();

            // Does not compile :-(
            p.Process(query);

            // Must explicitly write all arguments
            p.Process&lt;SomeQuery, string&gt;(query);
        }
    }

Why is this? What am I missing here?

Here&#39;s the compiler error message (it doesn&#39;t leave much to our imagination):

&gt; The type arguments for method IQueryProcessor.Process&lt;TQuery,
&gt; TResult&gt;(TQuery) cannot be inferred from the usage. Try specifying the
&gt; type arguments explicitly.

The reason I believe C# should be able to infer it is because of the following:

 1. I supply an object that implements `IQuery&lt;TResult&gt;`.
 2. That only `IQuery&lt;TResult&gt;` version that type implements is `IQuery&lt;string&gt;` and thus TResult must be `string`.
 3. With this information the compiler has TResult and TQuery.

Why doesn&#39;t C# infer my generic types?

In an Android string resource, how do I enforce a space?

For example, when I do &quot; result&quot; rather than &quot;result&quot; I still see &quot;result&quot; in my application&#39;s text view.

Enforcing spaces in string resources

<p>In an Android string resource, how do I enforce a space?</p>
<p>For example, when I do " result" rather than "result" I still see "result" in my application's text view.</p>


I&#39;m new to Android developing, and I would like to know what is the connection or difference between the version and the API level. What is each one referring to? And what does it mean when I decide to develop some app for API 14 or for android version 4.0?  

Or is one a subset of the other? I simply didn&#39;t get the difference, and why are there two counters?

Thanks

Android: API level VS. Android version

When the BACK button is pressed on the phone, I want to prevent a specific activity from returning to its previous one.

Specifically, I have login and sign up screens, both start a new activity called `HomeScreen` when successful login/signup occurs. Once HomeScreen is started, I want to prevent the users from being able to return to the login or sign up screens by pressing the BACK key. 

I tried using `Intent.FLAG_ACTIVITY_NO_HISTORY`, but since the application has Facebook integration, when the &#39;Login with Facebook&#39; is used, Facebook should return to the initial login screen, therefore I should keep a history of these activities.

I thought of overriding the behaviour of the BACK button on `HomeScreen` to directly finish an application when the button is pressed and I used

    @Override
	public void onBackPressed() {
		finish();
	}

but that also does not work.


How to prevent going back to the previous activity?

I am creating a ClickableSpan, and it is displaying properly with
the proper text underlined. However, the clicks are not registering.
Do you know what I am doing wrong???

Thanks, Victor

Here is the code snippet:
```java
view.setText(&quot;This is a test&quot;);
ClickableSpan span = new ClickableSpan() {
    @Override
    public void onClick(View widget) {
        log(&quot;Clicked&quot;);
    }
};
view.getText().setSpan(span, 0, view.getText().length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
```

Android ClickableSpan not calling onClick

I am generating a string from database dynamically which has the same name of image in `drawable` folder.

Now I want to set that value for `ImageView` using `setImageDrawable(R.id.StringGenerated)` dynamically.

Any Suggestions.. 


Using setImageDrawable dynamically to set image in an ImageView

Here&#39;s my code so far:

    String path = Environment.getExternalStorageDirectory().toString()+&quot;/Pictures&quot;;
        	
        	AssetManager mgr = getAssets();
        	
            try {
                
            	String list[] = mgr.list(path);
                Log.e(&quot;FILES&quot;, String.valueOf(list.length));
                
                if (list != null)
                    for (int i=0; i&lt;list.length; ++i)
                        {
                            Log.e(&quot;FILE:&quot;, path +&quot;/&quot;+ list[i]);
                        }
                
            } catch (IOException e) {
                Log.v(&quot;List error:&quot;, &quot;can&#39;t list&quot; + path);
            }

Yet while I do have files in that dir, it returns me list.length = 0... any ideas?


How to list files in an android directory?

I have four strings and any of them can be empty. I need to join them into one string with spaces between them. If I use:

    new_string = string1 + &#39; &#39; + string2 + &#39; &#39; + string3 + &#39; &#39; + string4

The result is a blank space on the beginning of the new string if `string1` is empty. Also, I have three blank spaces if `string2` and `string3` are empty. 

How can I easily join them without blank spaces when I don&#39;t need them?

Joining multiple strings if they are not empty in Python

I need to convert string like &quot;/[\w\s]+/&quot; to regular expression.

    &quot;/[\w\s]+/&quot; =&gt; /[\w\s]+/

I tried using different `Regexp` methods like:

`Regexp.new(&quot;/[\w\s]+/&quot;) =&gt; /\/[w ]+\//`, similarly `Regexp.compile` and `Regexp.escape`. But none of them returns as I expected.

Further more I tried removing backslashes:

`Regexp.new(&quot;[\w\s]+&quot;) =&gt; /[w ]+/ ` But not have a luck.

Then I tried to do it simple:

    str = &quot;[\w\s]+&quot;
    =&gt; &quot;[w ]+&quot;

It escapes. Now how could string remains as it is and convert to a regexp object?

Convert a string to regular expression ruby

I&#39;ve been using string.join() method in python 2 but it seems like it has been removed in python 3. What is the equivalent method in python 3? 

string.join() method let me combine multiple strings together with a string in between every other string. For example, string.join((&quot;a&quot;, &quot;b&quot;, &quot;c&quot;), &quot;.&quot;) would result &quot;a.b.c&quot;. 

Python 3 string.join() equivalent?

1. What are the design reasons of making Python strings immutable? How does it make programming easier?
2. I&#39;m used to mutable strings, like the ones in C. How am I supposed to program without mutable strings? Are there any best practices?

Why are Python strings immutable? Best practices for using them

I want to remove the very last character of a string, but before I do so I want to check if the last character is a &quot;+&quot;. How can this be done?

Content Type	Original Author	Original Content on Stackoverflow
Question	SK9	View Question on Stackoverflow
Solution 1 - Android	Andreas Klöber	View Answer on Stackoverflow
Solution 2 - Android	Lasse Samson	View Answer on Stackoverflow
Solution 3 - Android	Tang Chanrith	View Answer on Stackoverflow

Enforcing spaces in string resources

Android Problem Overview

Android Solutions

Solution 1 - Android

Solution 2 - Android

Solution 3 - Android

Why doesn't C# infer my generic types?

Rails: Update model attribute without invoking callbacks

Attributions