Google推荐v7 appcompat Toolbar还是AndroidX？求技术标准及两者优劣

Hi there, let’s clear up your confusion around App/Action Bar implementations—since Google’s library recommendations have shifted significantly since that 2019 guide, it’s totally valid to wonder which path to follow.

Google’s Current Official Technical Standard #

First things first: AndroidX is now the sole supported and recommended library suite for modern Android development. Google launched AndroidX back in 2018 to replace the old support library ecosystem (including the v7 appcompat library). As of today, the v7 appcompat library is officially deprecated—no new features, bug fixes, or security patches are being released for it. All ongoing development and support for UI components like Toolbar (the modern replacement for ActionBar) happens exclusively in AndroidX.

Pros & Cons: v7 AppCompat vs AndroidX #

v7 AppCompat Library #

• Pros:
  • Ideal for maintaining legacy projects (created before 2019) without needing large-scale code refactoring
  • Has a mature set of community resources and documentation for older Android version compatibility
• Cons:
  • No longer maintained—any future compatibility issues or security vulnerabilities won’t be addressed by Google
  • Cannot integrate with modern Jetpack components (like ViewModel, Navigation, or LiveData) or new Material Design features
  • Fully incompatible with AndroidX libraries—you can’t mix the two in a project, limiting future extensibility

AndroidX Library #

• Pros:
  • Receives continuous updates, including new features, performance improvements, and security patches
  • Seamlessly integrates with the entire Jetpack ecosystem, enabling modern Android development best practices
  • Uses a unified namespace (androidx.*) that eliminates the versioning chaos of the old support libraries
  • Offers enhanced Toolbar implementations like MaterialToolbar (part of the Material Components library), which supports Material Design 3 styling, dynamic color adaptation, and more flexible customization
• Cons:
  • Migrating an existing v7-based project requires code refactoring (though Android Studio provides a one-click migration tool via Refactor > Migrate to AndroidX that handles most changes automatically)
  • A small number of very old third-party libraries may not yet support AndroidX, requiring you to either wait for updates or find alternatives

Practical Recommendation for App/Action Bar Implementation #

For any new project, skip v7 AppCompat entirely and use AndroidX’s androidx.appcompat.widget.Toolbar or com.google.android.material.appbar.MaterialToolbar (for Material Design compliance). Here’s a quick example of setting up a MaterialToolbar:

Layout XML #

<com.google.android.material.appbar.MaterialToolbar
    android:id="@+id/main_toolbar"
    android:layout_width="match_parent"
    android:layout_height="?attr/actionBarSize"
    android:background="?attr/colorPrimaryContainer"
    app:title="My App"
    app:menu="@menu/main_menu"
    app:titleTextColor="?attr/onPrimaryContainer"/>

Activity Setup (Kotlin) #

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)
    
    val toolbar = findViewById<MaterialToolbar>(R.id.main_toolbar)
    setSupportActionBar(toolbar)
    
    // Optional: Enable back button
    supportActionBar?.setDisplayHomeAsUpEnabled(true)
}

If you’re working on an existing project using v7 AppCompat, prioritize migrating to AndroidX as soon as possible. The long-term benefits of ongoing support and access to modern features far outweigh the short-term migration effort.

内容的提问来源于stack exchange，提问作者Michele Dorigatti