DataBinding：如何使用BaseActivity / 如何使用抽象类

Question

我正在尝试将DataBinding添加到我的应用程序中。在我的应用程序中，我有一个BaseActivity，其中包含一个Toolbar和一个FrameLayout。 FrameLayout是扩展BaseActivity的活动的容器。如何将数据绑定添加到我的BaseActivity和扩展活动中？

以下是我未使用DataBinding的代码：

这是我的BaseActivity.java：

public class BaseActivity extends AppCompatActivity {


    @Override
    public void setContentView(@LayoutRes int layoutResID) {

        LinearLayout container = (LinearLayout) getLayoutInflater().inflate(R.layout.activity_base, null);
        FrameLayout activityContent = (FrameLayout) container.findViewById(R.id.activityContent);
        getLayoutInflater().inflate(layoutResID, activityContent, true);

        super.setContentView(container);

        Toolbar toolbar = (Toolbar) container.findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem menuItem) {
        if (menuItem.getItemId() == android.R.id.home) {
            finish();
        }
        return super.onOptionsItemSelected(menuItem);
    }

    public void setTitle(String title) {
        getSupportActionBar().setTitle(title);
    }
}

这里是activity_base.xml文件：

<?xml version="1.0" encoding="utf-8"?>  
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"           
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools">

        <include
            android:id="@+id/toolbarLayout"
            layout="@layout/toolbar" />

        <FrameLayout
            android:id="@+id/activityContent"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />

    </LinearLayout>
</layout>

这是继承BaseActivity的活动：CardRecyclerViewActivity.java：

public class CardRecyclerViewActivity extends BaseActivity {

    RecyclerView recyclerView;
    ReplikAdapter adapter;
    ArrayList<Replik> replikListesi;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_card_recyclerview);
        replikListesiniDoldur();
        adapter = new ReplikAdapter(replikListesi, this, R.layout.item_card_replik);
        recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
        recyclerView.setAdapter(adapter);
        setTitle(R.string.cardRecylerView);
    }

    public void replikListesiniDoldur() {
        replikListesi = new ArrayList<Replik>();
        replikListesi.add(new Replik(R.drawable.harvey1, "Ben ihtimallere oynamam. Adama oynarım.", "Harvey Specter"));
        replikListesi.add(new Replik(R.drawable.harvey2, "Avukatlık doktorluğa çok benzer, acıtana kadar bastırırsın ve böylece nereye bakman gerektiğini anlarsın.", "Harvey Specter"));
        replikListesi.add(new Replik(R.drawable.harvey3, "İşte aramızdaki fark bu; Sen küçük kaybetmek istiyorsun ben ise büyük kazanmak.", "Harvey Specter"));
        replikListesi.add(new Replik(R.drawable.harvey4, "Benim hayallerim yok, hedeflerim var.", "Harvey Specter"));
    }
}

好的，我已经像这样将数据绑定添加到我的BaseActivity.java中：

public class BaseActivity extends AppCompatActivity {

    @Override
    public void setContentView(@LayoutRes int layoutResID) {

        ActivityBaseBinding binding = DataBindingUtil.inflate(getLayoutInflater(), R.layout.activity_base, null, false);

        getLayoutInflater().inflate(layoutResID, binding.activityContent, true);

        super.setContentView(binding.getRoot());

        setSupportActionBar(binding.toolbarLayout.toolbar);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem menuItem) {
        if (menuItem.getItemId() == android.R.id.home) {
            finish();
        }
        return super.onOptionsItemSelected(menuItem);
    }

    public void setTitle(String title) {
        getSupportActionBar().setTitle(title);
    }
}

DataBinding 的 activity_base.xml：

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <include
            android:id="@+id/toolbarLayout"
            layout="@layout/toolbar" />

        <FrameLayout
            android:id="@+id/activityContent"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />

    </LinearLayout>
</layout>

但是我不确定如何在这种情况下将DataBinding添加到我的扩展活动中。你能帮我吗？

- Figen Güngör

---

你解决了这个问题吗？ - Jared Burrows

是的，确实如此。我逐个为每个活动添加工具栏，并从BaseActivity中删除了布局部分。 - Figen Güngör

@FigenGüngör，好问题。 - Hiren Patel

Answer 1

这个问题可能有点晚了。

你的 BaseActivity 应该像下面这样。

public abstract class BaseActivity<B extends ViewDataBinding, T extends BaseViewModel> extends AppCompatActivity {

    protected B dataBinding;
    protected T baseViewModel;

    protected void bindView(int layoutId) {
        dataBinding = DataBindingUtil.setContentView(this, layoutId);
    }

    @Override
    protected void onDestroy() {
        baseViewModel.detachView();
        super.onDestroy();
    }
}

您的MainActivity应该像以下这样。

public class MainActivity extends BaseActivity<ActivityMainBinding, MainActivityViewModel> implements MainActivityView, View.OnClickListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        bindView(R.layout.activity_main);

        baseViewModel = new MainActivityViewModel();
        baseViewModel.attachView(this);

        dataBinding.btnPerformOperation.setOnClickListener(this);

    }

    @Override
    public void OnDataLoad(String item) {
        dataBinding.setIsLoading(false);
        startActivity(new Intent(MainActivity.this, SecondActivity.class).putExtra("result", item));
    }

    @Override
    public void OnError(Throwable throwable) {

    }

    @Override
    public void onClick(View v) {
        dataBinding.setIsLoading(true);
        baseViewModel.loadNextData();
    }
}

参考源代码可以从这里下载。希望对你有所帮助。

- Hiren Patel

Answer 2

how about this?

BaseActivityViewModel.java

public class BaseActivityViewModel {
  public void onClick() {
    Log.i("BaseActivityViewModel | onClick", "111111111111");
  }
}

activity_base.xml

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">

  <data>

    <variable
      name="model"
      type="kr.changhoonjin.textmvvmwithextend.BaseActivityViewModel"/>
  </data>

  <LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <Button
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:onClick="@{()->model.onClick()}"
      android:text="base"/>

    <FrameLayout
      android:id="@+id/layout_container"
      android:layout_width="match_parent"
      android:layout_height="match_parent"/>

  </LinearLayout>
</layout>

BaseActivity.java

public class BaseActivity extends AppCompatActivity {
  private ActivityBaseBinding binding;

  @Override protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    binding = DataBindingUtil.setContentView(this, R.layout.activity_base);
    binding.setModel(new BaseActivityViewModel());
  }

  protected <T extends ViewDataBinding> T putContentView(@LayoutRes int resId) {
    return DataBindingUtil.inflate(getLayoutInflater(), resId, binding.layoutContainer, true);
  }
}

---

MainActivityViewModel.java

public class MainActivityViewModel {
  public void onClick2() {
    Log.i("MainActivityViewModel | onClick2", "2222222222222");
  }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">

  <data>

    <variable
      name="model"
      type="kr.changhoonjin.textmvvmwithextend.MainActivityViewModel"/>
  </data>

  <LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:orientation="vertical">

    <TextView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:text="Hello World!"/>

    <Button
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:onClick="@{()->model.onClick2()}"
      android:text="main"/>

  </LinearLayout>
</layout>

MainActivity.java

public class MainActivity extends BaseActivity {

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    ActivityMainBinding binding = putContentView(R.layout.activity_main);
    binding.setModel(new MainActivityViewModel());
  }
}

- Changhoon

Answer 3

这将与您在BaseActivity中所做的相同，只需使用setContentView而不是inflate

private ActivityCardRecyclerviewBinding binding;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    binding = DataBindingUtil.setContentView(this,R.layout.activity_card_recyclerview);
}

- Ravi

---

当我扩展BaseActivity并将数据绑定添加到扩展它的活动时，它给我返回了这个错误：Caused by: java.lang.RuntimeException: view tag isn't correct on view:null 在com.figengungor.suits.databinding.ActivityCardRecyclerviewBinding.bind(ActivityCardRecyclerviewBinding.java:95)处。 - Figen Güngör