kotlin中ViewBinding的使用

ViewBinding的优点：
仅仅支持绑定 View
不需要在布局文件中添加layout标签
需要在模块级build.gradle文件中添加 viewBinding = true 即可使用
效率高于DataBinding,因为避免了与数据绑定相关的开销和性能问题
相比于kotlin-android-extensions插件避免了空异常
Gradle配置：

// Android Studio 3.6
android {
    viewBinding {
        enabled = true
    }
}

// Android Studio 4.0
android {
    buildFeatures {
        viewBinding = true
    }
}

　　ViewBinding简单使用：

 

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Toast
import com.example.mychartdemo.databinding.ActivityMain2Binding

class MainActivity2 : AppCompatActivity() {

    private lateinit var binding: ActivityMain2Binding

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
       binding = ActivityMain2Binding.inflate(layoutInflater)
        setContentView(binding.root)
        binding.btn.setOnClickListener {
            Toast.makeText(this,"点击了按钮",Toast.LENGTH_SHORT).show()
        }
    }
}

　Fragment

class HomeFragment: BaseFragment() {

    private lateinit var binding: FragmentHomeBinding

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
    }

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        binding = FragmentHomeBinding.inflate(inflater,container,false)

        return binding.root
    }
}

　　

 java中使用

    1、Activity中

public class MainActivity extends AppCompatActivity {


    private ActivityMainBinding binding;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        binding = ActivityMainBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());
        binding.tvText.setText("呵呵fff哈哈哈");
    }
}

　　2、Fragment中

 

public class HomeFragment extends Fragment {

    private FragmentHomeBinding binding;

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        binding = FragmentHomeBinding.inflate(inflater,container,false);

        binding.tvText.setText("呵呵哈哈哈");
        return binding.getRoot();
    }
}

　　

　参考于：

https://blog.csdn.net/tanlove1314/article/details/114240299

https://www.jianshu.com/p/66728b95baaa

https://www.cnblogs.com/ymtianyu/p/13208548.html