Quick question, when I try to assign a variable to the id of a flipperview in an xml file, I get an issue that doesn't allow me to find the id of the flipper.
mFlipper = (ViewFlipper) findViewById(R.id.your_flipper); contains an error that the id of the flipper view is not there.
The flipper view won't take the id assigned in the xml file and place it in the R.java class for some reason.
Any ideas why or is the id of a flipper not supposed to be accessible in the class?
Either your layout XML file does not have the ViewFlipper under that ID, or you need to clean your project. To do the latter, use ant clean from the command line or Project > Clean from the Eclipse main menu.
Related
The problem is that when I rename the id of any view like a button in the xml file, the name of the view doesn't get updated in the activity while using view binding.
When I rename the id, I use (refactor) or (shift+f6).
This is a big problem because when ever I rename an id in the XML file, it will break the code in the activity in case I'm using View Binding.
Example:-
<Button
android:id="#+id/Button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
when I change Button1 to Button2, the code breaks in the activity in case I'm using View binding.
Can anyone give me any way to properly rename the IDs so that the names in the activity get updated automatically while using View Binding.
Please, remember I do use (refactor) not f2.
If you agree with me that this is a very urging problem and it breaks our code, please vote this question up, so it will be suggested to more android developers. Maybe some already found a solution.
Recently I came across the use-case of using tools:context in my layout files for activities.
I learned that I can use it to associate an Activity class file to my layout file.
But how can I use it to associate a Fragment class file to any layout?
Bacuase as I have tried, it is only showing Activity list in autocomplete suggestion.
There is a bug in Android Studio, you have to write it manually, it will appear red(indicating it's unresolved) until you finish typing, then it will appear in green
Have you tried it doing like this:
Let's say Relative layout is your parent layout in your fragment's layout:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".Folder.Fragment" >
Now this .xml file will be associated with your .Fragment class which is a fragment.
Key point: Autocomplete is not showing name, manually enter it and it will compile.
Create a fragment with a layout file and see the layout file for tools:context.
I just had the same problem and typing in the fragment name didn't get the fragment name recognized in the tools:context=".NameFragment" statement.
What did work was first deleting both the class and xml files for that fragment and then:
Right click on the package name and choose New->Fragment->Fragment (Blank)
Enter in your fragment name (the layout name is automatically created on the same form) and click Finish.
This method created both the class and xml files at the same time. and at this point, the tools:context statement in my xml file had my fragment name automatically and was not red but green text (indicating that it was recognized). I'm seeing this on Android Studio Bumblebee 2021.1.1.
Earlier I had created the xml file first and then created the class file (and had problems with the fragment class file name not being recognized by the tools:context statement).
This question is quite basic. Let me go with an example.
I have two activities
activity_a.xml
ActivityA.java
activity_b.xml
ActivityB.java
Both the XML files contain only a TextView to display a simple text. As usual, the TextViews are going to be referenced in the corresponding .java files using their View id
My question is, if it is right to reference the TextView in both the XML files with same id? (like using the below code with exactly same id for activity_a.xml and activity_b.xml)
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="#+id/textview"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
I was practising this procedure without any problems. When trying to reach the corresponding xml code for the TextView using Ctrl + Click (on Windows), I am provided with two options (to display the TextView's xml code from activity_a.xml or from activity_b.xml).
Also, what is the recommended way to name a View in Android? This will be helpful, when your Android project contains multiple layout files.
Yes , if you have same name of view or view group in different layout then it tells from which layout file it belongs to, ask for select required layout file.
so for that you have to follow proper naming conventions to avoid this type of confusion
https://github.com/ribot/android-guidelines/blob/master/project_and_code_guidelines.md
or you can give name like
activity_home_tvUserName if username textview from home activity
and
activity_profile_tvUserName if username textview from profile activity.
if it is right to reference the TextView in both the XML files with same id?
It is totally fine, the compiler will only look at the ID under a single view hierarchy.
e.g.: findViewById(R.id.textview) inside ActivityA.java will only search for textview ID inside activity_a.xml (assuming you have setContentView(R.layout.activity_a); beforehand.
what is the recommended way to name a View in Android?
In my opinion, you just need to be consistent in naming your view throughout the app. The main goal is to avoid misinterpretation and confusion.
Hope it helps!
They are in different activities, so you should have no problem using the same id. you could event declare them both as #+id/textview. However, why not just use the same XML file for both activities? No reason you can't.
You can also create an ids.xml file under the values folder and declare all your ids under it, so you don't have to declare them in your layouts, but this is not a very common approach.
if it is right to reference the TextView in both the XML files with same id?
My answer is Yes, It is right.
Whenever we set the setContentView(R.layout.activity_a), then it'll search for the given id within the above activity. Local attribute having the same id will take the more preference over the other attributes with the same id.
But having unique id's is Best practice.
I am working on an Android application that will be using images and so I am working being able to grab an image and display it. Though when I put in setContentView(R.layout.main); It tells me that main does not exist but offer to put into the layout file or R.java. When trying to place it into the file and save the R.java files tells me it reverted it right back to the original purpose, why is that?
From your comments you said you have activity_main.xml and not main.xml
So change to
setContentView(R.layout.activity_main);
ALso if you have imported R.java remove the same. Make sure there are no errors in your resource files. Clean and build.
If you have a imageview in activity_main.xml with id gimg1 then
ImageView iv = (ImageView) findViewById(R.id.gimg1);
and import
import android.widget.ImageView;
Its the same to initialize if you have others view's in your xml
R.java file is generated automatically, you can't edit it. In your case tyr to clean your project via Project->Clean
I have an imageView in my main.xml file, that isn't setup with a source initially. I want to be able to dynamically change the image resource within the code. so lets so i have my imageView setup like this:
<ImageView
android:id="#+id/countryImage"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:contentDescription="#string/CountryImageContent"/>
So i try to access within my code like this:
ImageView img = (ImageView) findViewById(R.id.countryImage);
The problem is here. Eclipse is giving me an error saying that "countryImage cannot be resolved or is not a field". A quick peek into my R.java file is showing me that the imageView isn't actually in there. Why is this happening? Thanks.
look into your drawable and layout if there is any error
if not try cleaning your project
Go to Project > clean > select your project
if not then look into your imports for
your.packagename.R remove it
Project -> Clean.
That is the only solution to this.
Also make sure that among your import statements, you do not have this : import android.R
Check this link for a detailed procedure.
Note : I am assuming that there are no errors in your layout and drawable files, as errors in them may also lead to this problem.
make sure all resource files have only lowercase letters , numbers and the underscore character ("_") .
only if there are no errors in creating the R file (in the "gen" folder) , you can use the id of it.
I think it is the problem to giving the name of #string
Please Remove all UpperCase Character from #string/CountryImageContent and replace it with small character.
R.java file doesn't support any Uppercase character. It gives the same error when you declare the file name of any resources Like :- Image, XML, #string, etc...
Just rename CountryImageContent with country_image_content. it will work perfect.
Another option to try in this case is: File --> Invalidate Caches / Restart...