继承PreferenceActivity，报需要验证fragment是否有效

解决Android应用中isValidFragment()方法的问题

最新推荐文章于 2025-04-29 18:00:00 发布

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本文解决了一个在Android应用中遇到的错误：无法启动活动，原因是子类PreferenceActivity未重写isValidFragment()方法来验证片段类的有效性。通过提供解决方法，即重写该方法并检查片段类名，可以解决此问题。

错误如下：

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.jctek.earthquake/com.jctek.earthquake.FragmentPreferences}: java.lang.RuntimeException: Subclasses of PreferenceActivity must override isValidFragment(String) to verify that the Fragment class is valid! com.jctek.earthquake.FragmentPreferences has not checked if fragment com.jctek.earthquake.UserPreferenceFragment is valid.

原因：SDK19以上的安全限制，需要重写isValidFragment

protected boolean isValidFragment (String fragmentName)

Added in API level 19

Subclasses should override this method and verify that the given fragment is a
valid type to be attached to this activity. The default implementation returns
true for apps built for android:targetSdkVersion older than KITKAT. For later
versions, it will throw an exception.

解决方法：

@Override
protected boolean isValidFragment (String fragmentName) {
return [YOUR_FRAGMENT_NAME].class.getName().equals(fragmentName);
}

或者

@Override
protected boolean isValidFragment (String fragmentName) {
return true;
}