Material-components-android: [MaterialAlertDialogBuilder] Crash building dialog with Material Components app theme

[hassieswift621]

Description: Attempting to build a AlertDialog using the MaterialAlertDialogBuilder causes the app to crash in a AppCompatActivity, even though the application theme is set to a Material Components theme.

Stacktrace

java.lang.IllegalArgumentException: The style on this component requires your app theme to be Theme.AppCompat (or a descendant).
        at com.google.android.material.internal.ThemeEnforcement.checkTheme(ThemeEnforcement.java:243)
        at com.google.android.material.internal.ThemeEnforcement.checkAppCompatTheme(ThemeEnforcement.java:213)
        at com.google.android.material.internal.ThemeEnforcement.checkCompatibleTheme(ThemeEnforcement.java:148)
        at com.google.android.material.internal.ThemeEnforcement.obtainStyledAttributes(ThemeEnforcement.java:76)
        at com.google.android.material.dialog.MaterialDialogs.getDialogBackgroundInsets(MaterialDialogs.java:60)
        at com.google.android.material.dialog.MaterialAlertDialogBuilder.<init>(MaterialAlertDialogBuilder.java:117)
        at com.google.android.material.dialog.MaterialAlertDialogBuilder.<init>(MaterialAlertDialogBuilder.java:103)
        at ninja.hassie.uni.todo.MainActivity$2.handleFault(MainActivity.java:69)
        at com.backendless.Persistence$1.handleFault(Persistence.java:189)

Expected behavior: The dialog should build as the app theme is set to a Material Components theme.

Source code:
styles.xml

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

MainActivity.java

public class MainActivity extends AppCompatActivity {
    ...
    new MaterialAlertDialogBuilder(getApplicationContext())
         .setMessage("Successfully added task")
         .setPositiveButton(android.R.string.ok, null)
         .show();

Android API version: 9 Pie

Material Library version: 1.2.0-alpha04

Device: OnePlus 5T

[ikim24]

Hi @hassieswift621 - The application's context isn't guaranteed to have the theme, so you'll either need to call setTheme on it or use the Activity's context.

[hassieswift621]

Thanks 😄

[asiawin]

Fixed my issue! Thanks

[i-tanova]

What?