二.带Header的基类Activity,并使用DataBind

1.实现抽象方法

protected abstract  void configHeader(HeaderViewModel headerViewModel);

对HeaderView对象进行修改，更改头部

public abstract  class HeaderAppCompatActivity extends BaseAppCompatActivity{
    private LinearLayout root_layout;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // 重点
        ActivityBaseBinding activityBaseBinding= DataBindingUtil.inflate(LayoutInflater.from(this),R.layout.activity_base,null,false);  
        
        HeaderViewModel headerViewModel = new HeaderViewModel();  
        
        configHeader(headerViewModel);
        
        activityBaseBinding.setHeaderViewModel(headerViewModel); 
        
        super.setContentView(activityBaseBinding.getRoot());


    }

    @Override
    public void setContentView(@LayoutRes int layoutResID) {
        setContentView(View.inflate(this, layoutResID, null));
    }

    @Override
    public void setContentView(View view) {
        root_layout = (LinearLayout) findViewById(R.id.root_layout);
        if (root_layout != null) {
            root_layout.addView(view, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
        }
    }
    
    /**
    *配置头部信息
    */
    protected abstract  void configHeader(HeaderViewModel headerViewModel);

}

<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">
    <data>
     <import type="android.view.View"></import>
    <variable
        name="headerViewModel"
        type="com.bilab.healthexpress.reconsitution_mvvm.base.viewModel.HeaderViewModel"></variable>
    </data>
    
     <!--头部-->  
    <LinearLayout
        android:id="@+id/root_layout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <android.support.v7.widget.Toolbar
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

           <TextView
                    android:text="@{headerViewModel.headerName}"
                    tools:text="标题"></TextView>

        </android.support.v7.widget.Toolbar>


    </LinearLayout>
</layout>

public  class HeaderViewModel  {
    public String headerName="";
    public boolean rightVisible=false;
    public boolean leftVisible=true;
    public void leftImageOnclick(View view){
           Context context= view.getContext();
           if(context instanceof Activity){
               Activity activity= (Activity) context;
               activity.finish();
           }
    }
}