Develop Reference

how is an object created?

EditText text1;
text1 = (EditText) findViewById(R.id.editText1);
text1.getText().toString();
Hi im new to android programming an need a little help. :) I just want to clarify if text1 is an object? Because it can call a method. But if text1 is an object how come that there is no "new" keyword. Thanks in advance for any response. :)

It is not necessary that all variables do initialization with new keyword.
Like if you write
String s = "";
Your String has been initialized without new keyword.
Same like this EditText is provided initialization in findViewById(). Here findViewById returned Edittext instance.
I suggest you complete Java Tutorial before continue work on Android. Because Android is based on Java language.

EditText is derived from the Super class View. Here findViewById method is returning an an object of the View class. You are explicitly typecasting it to EditText and assigning it to text1. So new is not required. It is being managed in findViewById method. Alternatively you can do this as:
EditText text1;
text1 = new EditText(An instance of Context); //Create an object of Edittext class
Now do whatever with this object text1.

It's me 2 years after, Now I want to answer your question bud. I know you just started and had a dream of creating apps that will be used by others, and guess what? You already achieved that and you can now also create apps not just for android but for IOS since you're using flutter now, you also have your own account on google play store now. Listen Bud, on the first line you declare what type is the text1. on the second line that's where you declare the text1 as an object now, then on the third line you are then using that object's capabilities like getting text. You've learned so much in this journey, and still learning not just in programming but in life.

Logic behind the creation of an Instance of a Button vs the creation of an instance of a plain Class?

I can't understand the logic behind the following code in android studio when we create an instance of a Button:
Button btn = (Button) findViewById(R.id.btnRegister);
From what I know an instance of a class is defined like:
MyClass myInstance = new MyClass(MyParameter)
If we apply the above logic the button code should be like this:
Button btn = new Button(findViewById(R.id.btnRegister));
But in fact the above code does not work. Why is "button" code so complicated to understand and does not relate to the code of a mere class? What does "(Button)" in brackets mean in the above example????
Thank you

The find view line doesn't create a button. Your views are all created using the standard new syntax by the framework when you call setContentView. The setContentView function parses your xml and creates the appropriate classes. What findViewById does is search the views that it created in setContentView checking the ids for one with a matching id and returns it.
As for what (Button) does- its a standard Java cast. findViewById returns a View object. But some subclasses of View have advanced functionality not found on view. To use them, you have to have an object of the correct type. So you cast it to the correct type (which will throw an exception if it isn't the right type). For example you need to have a TextView to call setText, a normal View doesn't have that function.

Xamarin: Setting text for a TextView programmatically

This is probably a mistake or lack of comprehension on my part, but I am quite confused right now. I'm trying to set a TextView in my Xamarin Android application programmatically. Here's my code:
TextView currentCharacterName =
FindViewById(Resource.Id.characterName);
currentCharacterName.SetText("test");
Unfortunately, this does not work, as I get the error "Argument 1: cannot convert from 'string' to 'int'". After reading in the available methods for SetText, I noticed the method I'm trying to call demands a ResId. I don't really understand why I would need a ResId to modify the text of a TextView.
I tried searching on Google for answers, and I came across this answer from 2014 that had the exact same problem as I do. The solution was to use the Text() method instead to set the TextView. Unfortunately, when I try this solution, I get the error "Non-invocable member 'TextView.Text' cannot be used like a method". When I try to check the Text method description, I see "string TextView {get/set} To be added."
Does this mean there's no implementation yet to set the text of a TextView? I am really reluctant to believe this, as it baffles me that such a big framework like Xamarin wouldn't even have get/set functions for something as simple as setting the text of TextView. I feel like there's a very simple solution for my problem, but I can't seem to find it.

TextView.SetText(X) allows you to set the text from a Resource id:
currentCharacterName.SetText(Resources.Id.MyString);
You are looking for the Text property:
currentCharacterName.Text = "test";
Xamarin: TextView class
Android.Widget.TextView.Text Property
Syntax:
public String Text { get; set; }

Test this code:
TextView currentCharacterName = FindViewById<TextView>(Resource.Id.characterName);
currentCharacterName.Text = "Your Text";

Android Button integer ID

I would like to have a function that if called can be passed the name of the button and then change the text of said button. I have attempted to use the function findViewById but it wont let me pass a string as it takes a int. This is my question, how can i store the integer value of the Button id's so i can pass to this function?

You could use tags if you need to deal with Strings. Set a tag on the Button using the android:tag xml attribute or setTag. Then you can use findViewWithTag to get a reference to the button.
But it'd probably be easier to just use IDs referenced from the resources object R: R.id.button

MenuItem#getTag()

On subclasses of View there is a getTag() method, which returns the android:tag attribute's value from .xml.
I would like the same for a MenuItem... is it okay to just cast it to a View?
Because item elements also allow a tag attribute in .xml...
Update: My goal with this is setting a tag in .xml, i.e. "notranslate", and querying it at runtime (we localize by hand at runtime, don't ask...)

It is always alright to cast, however, casting any Interface cannot be checked at compile time, only runtime. This is normally the reason many do not recommend casting an Interface that you have no control over. Having the proper error checking code is the best way to insure that such a cast does not break your code.
For the casting, it doesn't really matter whether the MenuItem is an Interface or a View, but the object it references must be one of View's subclasses, if not a View itself. If you are going to cast it, try the cast and catch a ClassCastException just in case as this is the error that will be thrown in runtime.
Another option is that since the MenuItem is simply an interface, you can easily just create a View subclass that utilizes MenuItem allowing you to do the cast. If you are doing a custom ContextMenu as many launchers do, then chances are your answer is nearly complete.
Hope this helps,
FuzzicalLogic

MenuItem is an interface. Any class can implement this interface and so it will not always be safe to cast the MenuItem to a View. You can use the "instanceOf" operator to test to see if the object that implements the MenuItem interface is indeed a View or not.
I understand that you want to define a flag in the XML definition of the menu and then at run time interrogate that flag to make a programmatic decision.
The Menu Resource Documentation records what attributes can be set in the XML. You can consider using (abusing) one of those settings such as the "android:alphabeticShortcut" to encode the flag and use the MenuItem::getAlphabeticShortcut() method to get the value. This does not require casting - it just uses the existing fields in the MenuItem XML construct/class for your own purposes.
Perhaps a less hacky way to do this is to keep a simple table in a separate assets file that lists the menu item identifiers and the special behavior associated with that identifier such as to translate or not to translate.
Alternatively create a simple class that has a table with this configuration information hard coded using the logical "#[+][package:]id/resource_name" resource identifier as the keys to the table. While this doesn't keep it all in one place (in the XML) it does it in a manner that is not encoding information in unused attributes, or relying on the ids not changing. The "table" could be implemented as a static method with an embedded switch statement allowing code such as "if (TranslationTable.shouldTranslate(menuItem.getItemId())) { do translation }"

I had a similar problem in that I wanted to associate some arbitrary data with each menu item so that I could handle menu items in a generic way without having to use hardcoded checks for individual item ids in code.
What I did was for a particular menu item (e.g. #+id/foo) There was an a TypedArray that was defined using the same name as the menu item ID. You could do this with other types of resources as well.
So to do the association, you get the resouce entry name (foo in my example) and then use that to look up the id of the other resource of a different type (#array/foo in my example).
In my handler for menu I had code like this:
Resources resources = getResources();
String name = resources.getResourceEntryName(item.getItemId());
int id = resources.getIdentifier(name, "array", "com.example");
if(id != 0)
{
TypedArray data = resources.obtainTypedArray(id);
// Use the typed array to get associated data
}
EDIT:
Actually it is even easier than that. There is nothing special about the ids on menu items other than you don't want multiple menu items with the same id. The id does not have to be of the form #+id/foo. It can actually also refer to other resources. So in my example above, instead of having the menu have an id of #+id/foo and using the resource manager to use that to find #array/foo, I changed to actually have the menu item have the id of #array/foo.
Now in my onOptionsItemSelected I have this:
Resources resources = getResources();
if("array".equals(resources.getResourceTypeName(item.getItemId())))
{
TypedArray data = resources.obtainTypedArray(item.getItemId());
// Use the typed array
}