ViewBinding基本使用

开启ViewBinding，只需在app -> build.gradle中增加一下配置

android {
    ...
    buildFeatures {
        viewBinding true
    }
}

ViewBinding会在编译期根据layout文件生成对应的class，如：first_layout.xml，会生成FirstLayoutBinding的class。
在Activity中创建ViewBinding实例， 并在适当的时候访问其成员

import com.example.activitytest.databinding.FirstLayoutBinding

class FirstActivity : AppCompatActivity() {

    private  lateinit var binding: FirstLayoutBinding
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = FirstLayoutBinding.inflate(layoutInflater)
        val view = binding.root
        setContentView(view)
        binding.button1.setOnClickListener {
            Toast.makeText(this, "You clicked Button ", Toast.LENGTH_SHORT).show()
        }
    }
}