运行Android应用出现Attr/colorPrimary重复定义错误求助

Hey there, let's tackle this frustrating duplicate attribute error you're facing. This issue almost always boils down to either a duplicate declaration in your own code, a dependency conflict, or a corrupted Gradle cache. Here's how to fix it step by step:

1. Check Your Local Resource Files for Duplicate Declarations #

First, head to your project's res/values folder and look for files like attrs.xml or values.xml. Search for <attr name="colorPrimary" ...> — if you see this line more than once, delete the duplicate entry.

Remember: colorPrimary is already defined by the AppCompat-v7 library, so you don't need to declare it yourself in attrs.xml. You only need to set its value in your theme (like in styles.xml).

2. Resolve Dependency Conflicts #

Sometimes a third-party library you're using might also include a version of AppCompat or define the same colorPrimary attribute, causing a conflict. To diagnose this:

• Open Android Studio's Terminal and run the dependency tree command:

  # Windows
  gradlew.bat app:dependencies
  # macOS/Linux
  ./gradlew app:dependencies
  

• Look for duplicate entries of com.android.support:appcompat-v7 (or androidx.appcompat:appcompat if you're using AndroidX). If you find one, exclude the duplicate from the problematic library in your build.gradle (Module level):

  implementation('com.example.thirdparty:library:1.0.0') {
      exclude group: 'com.android.support', module: 'appcompat-v7'
  }
  

3. Clean Gradle Cache and Rebuild the Project #

Corrupted Gradle cache files often cause weird resource duplication errors. Try these steps:

• Delete the cache folder mentioned in your error: C:\Users\jonat\.gradle\caches\transforms-1
• In Android Studio, go to File > Invalidate Caches... and select Invalidate and Restart
• After the IDE restarts, run Build > Clean Project followed by Build > Rebuild Project

4. Verify Your Theme Setup #

Double-check your app's theme in styles.xml to make sure you're not accidentally redefining the attribute:

<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <!-- Correct: Set the value of the existing colorPrimary attribute -->
    <item name="colorPrimary">@color/your_custom_primary_color</item>
    <!-- Wrong: Don't declare the attribute here or in attrs.xml -->
    <!-- <attr name="colorPrimary" format="color" /> -->
</style>

If you follow these steps, the duplicate colorPrimary error should disappear. Let me know if you hit any snags!

内容的提问来源于stack exchange，提问作者Jonathan Souza