How to fix: “You need to use a Theme.AppCompat theme (or descendant) with this activity”

问题

I am having trouble running my Android app in a fullscreen mode per instructions of a video. When it tries to run, the app crashes with the error.

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

Manifest File

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.djsg38.hikerswatch">

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET" />

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity android:name=".MainActivity"
        android:theme="@android:style/Theme.NoTitleBar.Fullscreen" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

</manifest>

Styles File

<resources>

<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <!-- Customize your theme here. -->
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>
</style>

Partial MainActivity that may be useful

public class MainActivity extends AppCompatActivity {

回答1:

Your application has an AppCompat theme

<application
    android:theme="@style/AppTheme">

But, you overwrote the Activity (which extends AppCompatActivity) with a theme that isn't descendant of an AppCompat theme

<activity android:name=".MainActivity"
    android:theme="@android:style/Theme.NoTitleBar.Fullscreen" >

You could define your own fullscreen theme like so (notice AppCompat in the parent=)

<style name="AppFullScreenTheme" parent="Theme.AppCompat.Light.NoActionBar">
    <item name="android:windowNoTitle">true</item>
    <item name="android:windowActionBar">false</item>
    <item name="android:windowFullscreen">true</item>
    <item name="android:windowContentOverlay">@null</item>
</style>

Then set that on the Activity.

<activity android:name=".MainActivity"
    android:theme="@style/AppFullScreenTheme" >

Note: There might be an AppCompat theme that's already full screen, but don't know immediately

回答2:

u should add a theme to ur all activities (u should add theme for all application in ur <application> in ur manifest) but if u have set different theme to ur activity u can use :

 android:theme="@style/Theme.AppCompat"

or each kind of AppCompat theme!

回答3:

If you add the android:theme="@style/Theme.AppCompat.Light" to <application> in AndroidManifest.xml file, problem is solving.

回答4:

Used to face the same problem. The reason was in incorrect context passing to AlertDialog.Builder(here). Use only activity context.

来源：https://stackoverflow.com/questions/39604889/how-to-fix-you-need-to-use-a-theme-appcompat-theme-or-descendant-with-this-a

标签

android

android-appcompat

appcompatactivity