Kotlin/迁移到视图绑定

Question

我一直在关注YT视频制作测验应用程序，但最终我在绑定时遇到了这个错误：

• “kotlin android extensions”Gradle插件已被弃用
• 请使用本迁移指南(https://goo.gle/kotlin-android-extensions-deprecation)开始使用视图绑定的步骤(https://developer.android.com/topic/libraries/view-binding)和“kotlin parcelize”插件

但是，当我添加绑定例如tv_name.text，我得到错误的文本是期待变量和一切与其他绑定部分相同。

库部件

import android.content.Intent
import android.os.Bundle
import android.view.View
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.WindowCompat
import com.example.quizapp.databinding.ActivityResultBinding

代码部分

    class ResultActivity : AppCompatActivity() {

    private val binding by viewBinding(FragmentResultActivity::bind)

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_result)

        // Hide the status bar.
        //window.decorView.systemUiVisibility = View.SYSTEM_UI_FLAG_FULLSCREEN

        val userName = intent.getStringExtra(Constants.USER_NAME)
        binding.tv_name.text = userName

        val totalQuestions = intent.getIntExtra(Constants.TOTAL_QUESTIONS, 0)
        val correctAnswers = intent.getIntExtra(Constants.CORRECT_ANSWERS, 0)

        binding.tv_score.text = "Your Score is $correctAnswers out of $totalQuestions."

        binding.btn_finish.setOnClickListener {
            startActivity(Intent(this@ResultActivity, MainActivity::class.java))
        }
      }
   }

Answer 1

首先，你需要让android知道你正在使用视图绑定。所以去“Gradle Scricript”文件夹并打开应用程序级别build.gradle（模块：nameOfProject）文件和里面的android属性添加这个：

android {

// ------ VIEW BINDING SETTING ------
// this creates the binding object
buildFeatures{
    viewBinding true
}
// after set up, click on  "Sync Now"
}

然后在main活动中。kt：

class MainActivity : AppCompatActivity() {
    // Initialize binding object. if ActivityMainBinding is not ready in menu click "Build/Make project"
    private lateinit var binding:ActivityMainBinding
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        // view Bindig
//        binding default layout inflater
        binding= ActivityResultBinding.inflate(layoutInflater)
        // inflate the root views which is Linear Layout, we access with .root
        setContentView(binding.root)

        // Set click listeners
      ....
}

Answer 2

您需要正确初始化绑定变量。请使用以下代码：

class ResultActivity : AppCompatActivity() {

    private lateinit var binding: ActivityResultBinding

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityResultBinding.inflate(layoutInflater)
        setContentView(binding.root)

        // Hide the status bar.
        //window.decorView.systemUiVisibility = View.SYSTEM_UI_FLAG_FULLSCREEN

        val userName = intent.getStringExtra(Constants.USER_NAME)
        binding.tv_name.text = userName

        val totalQuestions = intent.getIntExtra(Constants.TOTAL_QUESTIONS, 0)
        val correctAnswers = intent.getIntExtra(Constants.CORRECT_ANSWERS, 0)

        binding.tv_score.text = "Your Score is $correctAnswers out of $totalQuestions."

        binding.btn_finish.setOnClickListener {
            startActivity(Intent(this@ResultActivity, MainActivity::class.java))
        }
      }
   } 

由于我没有您的可用资源，我认为您可能必须更改ActivityResultBinding的命名。然而，我很确定就是这样。

快乐编码！：）