Android 视图绑定（ViewBinding）在Activity、Fragment和Adapter中的用法（java）_viewbinding adapter

今天打开Butter Knife，发现作者说“This tool is now deprecated.  Please switch to view binding.”于是学习了一下这个新功能，在这里记录一下。

这个功能是用来代替findViewById的，使用之前首先要在模块的build.gradle中添加以下代码

android {
        ...
        viewBinding {
            enabled = true
        }
    }

当某个模块启用视图绑定功能后，每个 XML 文件都会生成一个绑定类。activity_main.xml的绑定类就叫ActivityMainBinding，以此类推。组件的命名规则也是一样的，比如一个id为login_btn的按钮，调用的时候就是loginBtn。以下是ViewBinding在Activity、Fragment和RecyclerView.Adapter下的用法：

1. Activity

ActivityMainBinding binding = ActivityMainBinding.inflate(LayoutInflater.from(this));
setContentView(binding.getRoot()); //用来返回 LinearLayout 根视图
binding.button.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
 
    }
});

2. Fragment

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

3. RecyclerView.Adapter

public static class ViewHolder extends RecyclerView.ViewHolder{
    
    public ViewHolder(ItemBinding itemBinding) {
        super(itemBinding.getRoot());
    }
}
 
@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    ItemBinding binding = ItemBinding.inflate(LayoutInflater.from(parent.getContext()), parent, false);
    return new ViewHolder(binding);
}