DataBinding报错：cannot find the setter for attribute xxx with parameter type xxx

朱雀 2021-11-04 15:56 290阅读 0赞

[https://blog.csdn.net/Dream2076/article/details/84305310][https_blog.csdn.net_Dream2076_article_details_84305310]

报错信息如下：

C:\Android\projects\LazySheep\app\build\generated\source\apt\debug\top\littlefogcat\lazysheep\DataBinderMapperImpl.java:18: 错误: 找不到符号
    import top.littlefogcat.lazysheep.databinding.UserProfileLayoutBindingImpl;
                                                 ^
      符号:   类 UserProfileLayoutBindingImpl
      位置: 程序包 top.littlefogcat.lazysheep.databinding
    
    > Task :app:buildInfoGeneratorDebug
    
    FAILURE: Build failed with an exception.
    
    * What went wrong:
    Execution failed for task ':app:compileDebugJavaWithJavac'.
    > android.databinding.tool.util.LoggedErrorException: Found data binding errors.
      ****/ data binding error ****msg:Cannot find the setter for attribute 'app:username' with parameter type androidx.lifecycle.LiveData<top.littlefogcat.lazysheep.model.UserProfile> on android.widget.TextView.
      file:C:\Android\projects\LazySheep\app\src\main\res\layout\user_profile_layout.xml
      loc:20:28 - 20:56
      ****\ data binding error ****
    
    
    * Try:
    Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
    
    * Get more help at https://help.gradle.org
    
    Deprecated Gradle features were used in this build, making it incompatible with Gradle 6.0.
    Use '--warning-mode all' to show the individual deprecation warnings.
    See https://docs.gradle.org/5.1.1/userguide/command_line_interface.html#sec:command_line_warnings
    
    BUILD FAILED in 2s

在检查了代码的确无误之后，看到这篇文章：[https://blog.csdn.net/Dream2076/article/details/84305310][https_blog.csdn.net_Dream2076_article_details_84305310]  
原来是没有添加kapt插件，添加之后就能正常运行了。

kapt的介绍在此：[https://www.kotlincn.net/docs/reference/kapt.html][https_www.kotlincn.net_docs_reference_kapt.html]

> kapt 即 Kotlin annotation processing tool（Kotlin 注解处理工具）缩写。  
> 在 Kotlin 中通过 kapt 编译器插件支持注解处理器（参见JSR 269）。  
> 简而言之，你可以在 Kotlin 项目中使用像 Dagger 或者 Data Binding 这样的库。

也就是说，kapt是kotlin使用的注解处理器

[https_blog.csdn.net_Dream2076_article_details_84305310]: https://blog.csdn.net/Dream2076/article/details/84305310
[https_www.kotlincn.net_docs_reference_kapt.html]: https://www.kotlincn.net/docs/reference/kapt.html