Undeclared namespace prefix "android" (for attribute "layout_width")
How can I fix this?
This says that android is not defined.
How can I solve it? please help
try to add this in the layout
xmlns:android="http://schemas.android.com/apk/res/android
here is an example:
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
Try to check some of these.
You see this error with an incorrect namespace, or a typo in the attribute. Like 'xmlns' is wrong, it should be xmlns:android
First node needs to contain: xmlns:android="http://schemas.android.com/apk/res/android"
If you are integrating AdMob, check custom parameters like ads:adSize, you need
xmlns:ads="http://schemas.android.com/apk/lib/com.google.ads"
If you are using LinearLayout you might have to define tools:
xmlns:tools="http://schemas.android.com/tools"
Related
I'd like to change and align the text, and possibly add features on appbar in the screen above.
However, it'd be best if I could find and modify the text and align it IF I don't intend to add features.
But then I wasn't able to find where in android studio I could change the text.
I thought I could find one in the main activity xml file but I couldn't. I looked up at themes.xml and AndroidManifest.xml but couldn't find a clue.
Here is first 13 lines of my main activity xml file just in case.
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<SurfaceView
android:id="#+id/surface_view"
android:layout_width="match_parent"
android:layout_height="480dp"
app:layout_constraintTop_toTopOf="parent"/>
So, to cut it short, where in android studio can I change the text in toolbar? or appbar? above in the screen without having to create toolbar.xml? (+ align the text in the center and change text color)
Apparantly you don't have toolbar implemented in your xml layout
In Your style file make sure you set it to noActionBar
<style name="Theme.ChatApp" parent="Theme.AppCompat.Light.NoActionBar">
Then you have to add your own toolbar
<androidx.appcompat.widget.Toolbar
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/toolbar"
android:background="#color/white"
app:navigationIcon="#drawable/ic_baseline_dashboard_24"
app:title="here you can put your title"/>
In your activity reference your toolbar in your onCreate
setSupportActionBar(findViewById(R.id.toolbar)
PS : If you are using MaterialToolbar please consider add this material library
implementation 'com.google.android.material:material:1.1.0'
I'm working on a information orientated app using the master/detail flow and so far, so good. I would like to add images to the TextView, but it's formatted differently then what I've experienced in the past and I'm lost. from my understanding of what I've read while searching is that the scrolling text is "newer" when generating the Master/detail activity, therefore I haven't found any information on this specific issue. I would also like to pass the images in using the content activity, so it would be-
addItem(new Item(ID,Name,Detail,Image1,Image2));
what the detail XML file looks like
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/bobblehead_detail"
style="?android:attr/textAppearanceMedium"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="16dp"
android:textIsSelectable="true"
tools:context="com.example.johnson.fallout4bobbleheadlocations.BobbleheadDetailFragment" />
I tried adding ImageView's under it, but I received errors.
tl;dr I would like to add 2 images under the scrolling TextView.
I am not sure if I clearly understand what you mean but looking at your xml it seems to me that you need to add a layout (either relative or linear) to your xml file and then add a textview and two imageviews (or whatever you want) into that layout.
Something like this:
<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"
android:padding="16dp" tools:context="com.example.somefragment">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/some_id2"
android:text="Here is your text"/>
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/some_id"
android:src="#drawable/image1"/>
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/some_id3"
android:src="#drawable/image2"/>
</RelativeLayout>
My plan is creating an Activity includes Tabs+Swipe for all Android version. If we set it from a default Android project, it has just support for at least API 11.
In Sherlock we have two project named : Tab Navigation, Tab Navigation(collapsed) includes Tabs but not Swipe.
They have Issue #240 in their samples that has a bug (swipe left/right when the tabs are in collapsed mode (landscape) and the selected item does not update).
Do you know any sample code that solve this problem?
You made this now with the default Android Support Library (or the ABS), with a ViewPager and a PagerTabStrip:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<android.support.v4.view.ViewPager
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v4.view.PagerTabStrip
android:id="#+id/tabStrip"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="top"/>
</android.support.v4.view.ViewPager>
</LinearLayout>
Then create an Adapter to the ViewPager that extends of FragmentStatePagerAdapter (for example) and override the method public CharSequence getPageTitle(int position) to provide a title for each tab.
Hope it helps.
I also happened to have same situation. Follow below links and you will get all what you need.
See this tutorial
http://droidista.blogspot.com/2012/08/making-actionbarsherlock-and.html
And get demo code from here
https://github.com/zmdominguez/vpi-abs-demo
I found these links which might help you out.
A page flipper control - like the android home screens
https://github.com/JakeWharton/Android-ViewPagerIndicator
I've recently started working on an Android app. I'm not a programming noob, I have been programming in Java since 2009, but this is my first Android app. I have tried following some tutorials on how to set the background colour but it simply isn't working for me. I can't work out what I'm doing wrong.
In my layout directory I have files called: main.xml and view_fact.xml. They both use the linear layout and my LinearLayout Tag is as follows:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#color/background_grey"
>
And in my "values" directory I the contents of "strings.xml" is:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="app_name">Facts</string>
<color name="background_grey">#E8E8E8</color>
</resources>
But the background colour is not changing from the default black.
I've also tried adding: "android:theme="#android:style/Theme.Light"" in my AndroidManifest.xml file.
None of this is working, any suggestions?
Thank you.
On my view_fact.xml page it looks like this:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#color/background_grey"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Fact:"
android:padding="10dp"
android:textColor="#080808"
/>
<TextView
android:id="#+id/factData"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="10dp"
android:text=""
/>
<Button
android:id="#+id/anotherFactButton"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Another Fact"/>
</LinearLayout>
What's interesting is that the text in "factData" is grey, while the text: "Fact:" in the Text View above is white, and I've tried to change it's colour to red and it doesn't work. It stays white.
Any suggestions? I still haven't managed to get this working; thank you.
If you want to use #color/color_name you have to create a Color.xml file and then it will be accessible in the manner you tried to use it.
Forgive the somewhat obvious questions, but: are you calling setContentView(R.layout.main) in your Activity onCreate? Is there something else in the layout that is filling the LinearLayout and covering the background grey?
Looking at the pastie you linked in the comment I think you need to remove the <?xml version="1.0" encoding="utf-8"?> line at the start. Eclipse won't build a freshly created app with that xml root in a layout..
Although that's strange as the first two examples I've found on the Android Developer site (for example) include it
I'd be interested to see what happens if you remove that line...
In Eclipse if I use
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#E8E8E8"
>
then the background colour changes.
If I change that to
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#string/background_grey"
>
by adding <string name="background_grey">#E8E8E8</string> to /res/values/strings.xml the background changes.
This also works if I declare it as android:background="#color/background_grey" in the layout and <color name="background_grey">#E8E8E8</color> in strings.xml
and if I setup res/values/colors.xml <= I've used colors.xml (while you've used color.xml) however http://developer.android.com/guide/topics/resources/more-resources.html tells us the filename is arbitrary as you can see by the declaration working in the strings.xml file
<?xml version="1.0" encoding="utf-8"?>
<resources>
<color name="background_grey">#E8E8E8</color>
</resources>
and declare the layout as
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#color/background_grey"
>
then the background also changes...
If it doesn't behave the same for you then there's something funky going on or you're using a different layout than the simple example above and, well, there's something funky going on in that layout.
Okay, I've tried lots of different methods of trying to set the background colour and none of them are working. And I'm now having problems with text not updating. So I'm going to try remaking it. Using eclipse and ill make a new question if I'm still having issues. Thanks for the suggestions.
I'm currently using the XML layout to set my Activity background. How can I do this in the Java code instead?
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#drawable/bg" >
Before calling Activity.setContentView(View) use one of the setBackground...() methods on your main View.
Set an id attribute to your parent RelativeLayout. Than find it by id in activity code and use setBackgroundResource method.