DataBinding onClick 的几种点击方式

1.@{click}

//xml:
<Button
     android:layout_width="match_parent"
     android:layout_height="48dp"
     android:onClick="@{click}"
/>

//ViewModel:
public void click(View view){

}

2.不带参数：@{() -> viewModel.click()}

//xml:
<Button
     android:layout_width="match_parent"
     android:layout_height="48dp"
     android:onClick="@{() -> viewModel.click()}"
/>

//ViewModel:
public void click(){

}

3.@{viewModel::click}

//xml:
<Button
     android:layout_width="match_parent"
     android:layout_height="48dp"
     android:onClick="@{viewModel::click}"
/>

//ViewModel:
public void click(View view){

}

tip: 如果是在其它类中设置点击方法，如 EventHandlers.java, 其实与上面一致

//xml:
<variable
    name="handler"
    type="com.xx.xxx.EventHandlers" />

<Button
     android:layout_width="match_parent"
     android:layout_height="48dp"
     android:onClick="@{handler::click}" />

// UI类：绑定handler,如绑定ViewModel那样
EventHandlers handler = new EventHandlers();
binding.setHandler(handler);

// EventHandlers 执行click事件
public void click(View view){
    //do
}

4.带参数：@{() -> viewModel.click(obj.id)}

//xml:
<variable
    name="viewModel"
    type="com.xx.xxx.ViewModel" />

<variable
    name="obj"
    type="com.xx.xxx.User" />
<Button
     android:layout_width="match_parent"
     android:layout_height="48dp"
     android:onClick="@{() -> viewModel.click(obj.id)}"
/>

//ViewModel:
public void click(long id){
     //do   
}

5.ObservableField<OnClickListener>

//xml:
  <variable
       name="iconView"
       type="com.xxxxx.IconView" />

  <RelativeLayout
        android:id="@+id/rl_icon_view"
        android:layout_width="match_parent"
        android:layout_height="55dp"
        android:onClick="@{iconView.clickListener}"
       >    

//IconView:
  public final ObservableField<OnClickListener> clickListener=new ObservableField<>();

//xml所在的Activity类：
  binding.iconView.clickListener.set(new View.OnClickListener() {
         @Override
         public void onClick(View v) {
              Toast.makeText(getApplicationContext(),"iconView",Toast.LENGTH_SHORT).show();
         }
  });

6.带参数

 android:onClick="@{()->loadingModel.chooseLang(2)}"
  public void chooseLang(int language) {
        LogUtil.i(TAG, "language=" + language);

  }

7. 带view的参数

//xml:
<variable
       name="listener"
       type="test.carrie.todomvvmtest.ui.OnTaskItemListener"/> 

android:onClick="@{(view)->listener.onCheckBoxClick(obj,view)}"


//adapter:
 public void onCheckBoxClick(ToDo entity, View v) {

        }