AppTheme冲突：自定义设计需无ActionBar但WeAccept SDK要求有ActionBar

Got it, let's resolve this crash while keeping your custom design requirements intact. The root issue here is that your app's global theme removes the ActionBar entirely, but the WeAccept SDK expects an ActionBar to exist in the theme to function properly. Here are two reliable solutions:

Solution 1: Assign a Dedicated Theme to the SDK's Activity #

This is the most targeted approach—you keep your app's NoActionBar theme for all your screens, but give the WeAccept SDK's payment screen a theme that includes an ActionBar.

1. First, add a new theme in your styles.xml that inherits from a theme with ActionBar support, and reuse your existing color/style configurations:

<style name="AppTheme.WithActionBar" parent="Theme.AppCompat.DayNight">
    <item name="colorPrimary">@color/DefaultPrimary</item>
    <item name="colorPrimaryDark">@color/DefaultPrimaryDark</item>
    <item name="colorAccent">@color/DefaultAccent</item>
    <item name="android:textColorHint">@color/DefaultPrimary</item>
    <item name="android:actionButtonStyle">@style/MyActionButtonStyle</item>
    <item name="android:typeface">serif</item>
</style>

2. Next, find the full class name of the WeAccept SDK's payment activity (you can get this from the crash log or the SDK documentation). Then add an <activity> entry for it in your AndroidManifest.xml, overriding its theme to the one you just created:

<activity
    android:name="com.weaccept.sdk.PaymentActivity" <!-- Replace with the actual SDK activity class name -->
    android:theme="@style/AppTheme.WithActionBar" />

This way, your app's screens stay free of the default ActionBar, while the SDK's screen gets the ActionBar it needs to run without crashing.

Solution 2: Keep ActionBar in Theme but Hide It Globally #

If you don't want to target individual SDK activities, you can adjust your base theme to retain ActionBar support but hide it from your app's UI. This lets the SDK detect the ActionBar exists, while your users won't see it.

Modify your styles.xml like this:

<style name="AppTheme" parent="Theme.AppCompat.DayNight">
    <item name="colorPrimary">@color/DefaultPrimary</item>
    <item name="colorPrimaryDark">@color/DefaultPrimaryDark</item>
    <item name="colorAccent">@color/DefaultAccent</item>
    <item name="android:textColorHint">@color/DefaultPrimary</item>
    <item name="android:actionButtonStyle">@style/MyActionButtonStyle</item>
    <item name="android:typeface">serif</item>
</style>

<style name="AppTheme.NoActionBar">
    <item name="windowActionBar">false</item>
    <item name="windowNoTitle">true</item>
</style>

Keep your existing Manifest configuration (android:theme="@style/AppTheme.NoActionBar"). The base AppTheme now inherits from a theme with ActionBar support, so the SDK will find what it needs, while the NoActionBar variant hides it from your app's screens.

Why This Crash Happens #

The WeAccept SDK likely calls methods like getSupportActionBar() without checking if it returns null. When your theme is set to NoActionBar, this method returns null, triggering a NullPointerException when the SDK tries to use it.

内容的提问来源于stack exchange，提问作者Hossam Hassan