You need to use a Theme.AppCompat theme (or descendant) with this activity.

Question

User106920 posted

Hi, I'm getting the error in thread title, however, I AM using the Theme.AppCompat, so I don't understand why I should have this error. My files are as follows:

AndrodidManifest.xml

 `android:theme="@style/AppTheme"`

values/styles.xml

<resources>

    <style name="AppTheme" parent="AppTheme.Base"/>

    <style name="AppTheme.Base" parent="Theme.AppCompat">

         <!-- colorPrimary is used for the default action bar background -->
        <item name="colorPrimary">@color/colorPrimary</item>

        <!-- colorPrimaryDark is used for the status bar -->
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>

        <!-- colorAccent is used as the default value for colorControlActivated,
             which is used to tint widgets -->
        <item name="colorAccent">@color/colorAccent</item>

    </style>

</resources>

values-v21/styles.xml

    <resources>
        <style name="AppTheme" parent="Theme.AppCompat">
        </style>       
    </resources>

I've tried many variations but nothing seems to work. I am using Xamarin.Android.Support.v7.AppCompat -Version 21.0.3.0.

Is this a bug?

Thanks Mike

Answer 1

User85826 posted

Had the same error, what did help is to delete Resources.Designer.cs file, build project, include generated Designer file into a project.

Answer 2

User135812 posted

Did that solve the problem?

Answer 3

User98607 posted

Try this one, error must be solved :

parent="Theme.AppCompat.Light.NoActionBar"

Answer 4

User157739 posted

Were you able to solve this problem? Neither parent="Theme.AppCompat.Light.NoActionBar" nore any extension of Theme.AppCompat has resulted in the correct theme for below API 21.

Answer 5

User97779 posted

According to this article, you need to install a Xamarin.Android.Support.v7.AppCompat/ to bring compatibility to older versions of Android, as low as Android API 10

Answer 6

User97779 posted

Also if you're using Xamarin forms, make sure MainActivity.cs inherits from FormsApplicationActivity

Answer 7

User193836 posted

Just perform a Build -> Clean All and run again. That solved my issues when i added a CoordinatorLayout

Answer 8

User209348 posted

@JosephKandi said: Just perform a Build -> Clean All and run again. That solved my issues when i added a CoordinatorLayout

This worked for me... thanks! :smile:

Answer 9

User243375 posted

You need to use a Theme.AppCompat theme (or descendant) with this activity.

For those who still have the problem, I fixed it changing in AndroidManifest.xml:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android">
    <uses-sdk android:minSdkVersion="15" />
    <application android:label="YOURPROJECTNAME" android:icon="@drawable/icon"></application>
</manifest>

by

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android">
    <uses-sdk android:minSdkVersion="15" />
    <application android:label="YOURPROJECTNAME" android:icon="@drawable/icon" android:theme="@style/MainTheme"></application>
</manifest>

Answer 10

User189201 posted

@alextn you just saved me a lot of headaches. Thanks for posting back with the solution!

Answer 11

User275516 posted

Hi, I followed BerayBentesen's Step

1) open Main.xaml layout in design mode and change the theme to which you wish 2) goto AndroidManifest.xml file and now change parent="Theme.AppCompat.Light.NoActionBar" or any other in Theme in Theme.AppCompat

this helped me. Thank you All

Answer 12

User142704 posted

The fix mentioned by 'Korayem' worked for me. If you're using Xamarin forms, make sure MainActivity.cs inherits from FormsApplicationActivity

Answer 13

User282668 posted

I solved this issue by adding Apptheme theme into manifest file.

Answer 14

User312982 posted

I needed to update the Xamarin.Forms version first and then perform Clean All which solved the problem.

Answer 15

User288585 posted

Here are the steps:

1. Go to Property-->Androidmanifest.xml It will open the file in IDE

Enter the value in the Application theme as @style/MagicTheme

Save it

2. Now go to Resources-->Values -- Add a file by style.xml
3. write the below code in style.xml

<style name="Theme" parent="MagicTheme.Base">

Answer 16

User366563 posted

@JosephKandi said: Just perform a Build -> Clean All and run again. That solved my issues when i added a CoordinatorLayout

Worked for me

Answer 17

User294608 posted

@JosephKandi said: Just perform a Build -> Clean All and run again. That solved my issues when i added a CoordinatorLayout

This also worked for me Thanks @JosephKandi

Answer 18

User367173 posted

@JosephKandi said: Just perform a Build -> Clean All and run again. That solved my issues when i added a CoordinatorLayout

This worked for me. Thank you!!

Answer 19

User347645 posted

@JosephKandi said: Just perform a Build -> Clean All and run again. That solved my issues when i added a CoordinatorLayout

THIS WORKS!

I think Xamarin generates the android manifest file at build time and it stays in debug/obj/android/ folder, cleaning the solution would get rid of it and makes everything back to "working" again.

However, if you are actually not using AppCompat theme (or any of its sub) then you need to fix that.

Thank you

Answer 20

User43729 posted

@AndreyKozhyn said: Had the same error, what did help is to delete Resources.Designer.cs file, build project, include generated Designer file into a project.

Thanks for the suggestion - this also worked for me.

Answer 21

User371959 posted

If you are using VS 2017 this worked for me:

Tools --> NuGet Package Manager --> Package Manager Console

Paste this into the PM console: Install-Package Xamarin.Android.Support.v7.AppCompat -Version 27.0.2

Then go to Project --> [YOURPROJECTNAME] Properties --> Android Manifest and make sure that the Target Android version is set to Android 8.1 (API Level 27 - Oreo)