DataBinding基本使用包括以下内容： - 单纯的摆脱findviewbyid - 绑定基本数据类型及String - 绑定Model数据 - 绑定事件 - 通过静态方法转换数据类型 - 通过运算符操作数据 - 自定义Binding的类名 - 绑定相同Model的操作 - model变量改变自动更新数据 - 绑定List/Map等集合数据 - Observable自动更新 - Databinding与include标签的结合 - DataBinding与RecyclerView的结合
布局文件
activity_five.xml
<?xml version="1.0" encoding="utf-8"?><!--布局以layout作为根布局--> <layout> <data > <import type="www.zhang.com.databinding.model.Content"/> <variable name="con" type="Content"/> </data> <!--我们需要展示的布局--> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:bind="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <include android:id="@+id/toolbar" layout="@layout/toolbar" android:layout_height="56dp" android:layout_width="match_parent" bind:content="@{con}" /> <!--通过命名空间将写有toolbar的xml文件中定义的content对象作为属性绑定con对象，这2个对象是同一个类--> <TextView android:text="@string/app_name" android:layout_width="match_parent" android:layout_height="wrap_content" /> </LinearLayout> </layout>toolbar.xml
<?xml version="1.0" encoding="utf-8"?> <layout > <data> <import type="www.zhang.com.databinding.model.Content"/> <variable name="content" type="Content"/> </data> <android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/toolbar" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_height="56dp" android:layout_width="match_parent" app:title="@{content.title}" app:subtitle="@{content.subTitle}" android:background="@color/colorPrimary" app:titleTextColor="@android:color/white" app:subtitleTextColor="@android:color/white" /> </layout>在activity_five.xml中的include属性中定义了一个id,同时又在toolbar.xml中的Toolbar标签中又定义了一个id,其作用是通过binding.toolbar.toolbar等同于Toolbar控件，可以方便做一些操作等
FiveActivity中
public class FiveActivity extends AppCompatActivity { @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); supportRequestWindowFeature(Window.FEATURE_NO_TITLE); ActivityFiveBinding binding =DataBindingUtil.setContentView(FiveActivity.this, R.layout.activity_five); Content con = new Content("Title","SubTitle"); binding.setCon(con); // binding.toolbar.setContent(con); //这个测试没有效果，不会显示toolbar的title/subTitle // binding.toolbar.toolbar.setTitle(""); // binding.toolbar.toolbar.setSubtitle(""); //下面的代码也可以通过DataBinding绑定数据 binding.toolbar.toolbar.setNavigationIcon(R.mipmap.ic_launcher); setSupportActionBar(binding.toolbar.toolbar); binding.toolbar.toolbar.setNavigationOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { finish(); } }); } }Content
public class Content extends BaseObservable { private String title; private String subTitle; public Content(String title, String subTitle) { this.title = title; this.subTitle = subTitle; } @Bindable public String getSubTitle() { return subTitle; } public void setSubTitle(String subTitle) { this.subTitle = subTitle; notifyPropertyChanged(BR.subTitle); } @Bindable public String getTitle() { return title; } public void setTitle(String title) { this.title = title; notifyPropertyChanged(BR.title); } }布局文件
activity_five.xml
<?xml version="1.0" encoding="utf-8"?><!--布局以layout作为根布局--> <layout> <data > <import type="www.zhang.com.databinding.model.Content"/> <variable name="con" type="Content"/> </data> <!--我们需要展示的布局--> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:bind="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <include android:id="@+id/toolbar" layout="@layout/toolbar" android:layout_height="56dp" android:layout_width="match_parent" bind:content="@{con}" /> <!--通过命名空间将写有toolbar的xml文件中定义的content对象作为属性绑定con对象，这2个对象是同一个类--> <android.support.v7.widget.RecyclerView android:id="@+id/recycler" android:layout_width="match_parent" android:layout_height="wrap_content" /> </LinearLayout> </layout>recycler_item.xml
<?xml version="1.0" encoding="utf-8"?> <layout> <data> <variable name="str" type="String"/> </data> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="wrap_content" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:orientation="vertical"> <TextView android:text="@{str}" android:gravity="center_vertical" android:textColor="@android:color/black" android:textSize="16sp" android:layout_width="match_parent" android:layout_height="48dp" /> </LinearLayout> </layout>FiveActivity
public class FiveActivity extends AppCompatActivity { private ActivityFiveBinding binding; @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); supportRequestWindowFeature(Window.FEATURE_NO_TITLE); binding = DataBindingUtil.setContentView(FiveActivity.this, R.layout.activity_five); initToolbar(); initRecyclerView(); } private void initRecyclerView() { LinearLayoutManager manager = new LinearLayoutManager(FiveActivity.this); binding.recycler.setLayoutManager(manager); binding.recycler.setHasFixedSize(true); MyAdapter adapter = new MyAdapter(getApplicationContext()); binding.recycler.setAdapter(adapter); } private void initToolbar() { Content con = new Content("Title","SubTitle"); binding.setCon(con); // binding.toolbar.setContent(con); //这个测试没有效果，不会显示toolbar的title/subTitle // binding.toolbar.toolbar.setTitle(""); // binding.toolbar.toolbar.setSubtitle(""); //下面的代码也可以通过DataBinding绑定数据 binding.toolbar.toolbar.setNavigationIcon(R.mipmap.ic_launcher); setSupportActionBar(binding.toolbar.toolbar); binding.toolbar.toolbar.setNavigationOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { finish(); } }); } }MyAdapter
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> { private Context mContext; String[] datas; public MyAdapter(Context context) { mContext = context; datas = context.getResources().getStringArray(R.array.item_list); } @Override public MyAdapter.MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { RecyclerItemBinding binding = DataBindingUtil.inflate(LayoutInflater.from(mContext), R.layout.recycler_item, parent, false); return new MyViewHolder(binding); } @Override public void onBindViewHolder(MyAdapter.MyViewHolder holder, int position) { String name = datas[position]; holder.getBinding().setVariable(www.zhang.com.databinding.BR.str,name); //holder.getBinding().setStr(name); //两者都可以 //executePendingBindings()方法说明 // When a variable or observable changes, the binding will be scheduled to change before the next frame. // There are times, however, when binding must be executed immediately. // To force execution, use the executePendingBindings() method. holder.getBinding().executePendingBindings();//此方法必须执行在UI线程，当绑定的数据修改时更新视图（不知道翻译的准不准） } @Override public int getItemCount() { return datas.length; } public class MyViewHolder extends RecyclerView.ViewHolder { private RecyclerItemBinding binding; public MyViewHolder(ViewDataBinding binding) { super(binding.getRoot()); this.binding = (RecyclerItemBinding) binding; } public RecyclerItemBinding getBinding() { return binding; } public void setBinding(RecyclerItemBinding binding) { this.binding = binding; } } }参考文章
Google官方文档
Android数据绑定框架DataBinding
Android-MVVM架构-Data Binding的使用
