How to set click listener to LinearLayout using data binding

问题

I am currently trying to set a click listener to a LinearLayout view in the .xml layout file using data binding.

I have managed to get it to work well on other views like a Button or TextView, but for some reason it is not working with a LinearLayout.

This is the bare bones of my attempts and I still cannot get it to work:

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="72dp"
    android:clickable="true"
    android:focusable="true"
    android:onClick="@{action::linearLayoutClicked}"
    android:orientation="vertical">
</LinearLayout>

Where linearLayoutClicked is my method defined in the action class:

public void linearLayoutClicked(View view) {
    // specific logic
}

I have also tried with child views and those child views with clickable and focusable set to false as well as duplicateParentState set to true and false.

That action is exactly the same action that is being used on other views which is working correctly.

Is this a bug or am I doing this incorrectly? Why is this not working for LinearLayout but works without any problems for other views?

回答1:

You can handle any view click event like below. Hope it helps!

1) Create interface for handle click event like below.

interface OnClickHandlerInterface {
    void onClick(View view)
}

2) Implement that click listener in action class as shown below

class MainActivity implements OnClickHanderInterface{
    @Override
    void OnClick(View view){

    }
}

3) Now bind this interface in XML file.

<data>

    <variable
        name="clickHandler"
        type=".OnClickHandlerInterface" />
</data>

4) Now register this interface in action class with use of binding object

mActivityMainBinding.clickHandler = this

5) Now set onClick on any which you want to set click listener. For you it's LinearLayout

<LinearLayout
    android:id="@+id/linearLayout"
    android:layout_width="match_parent"
    android:layout_height="72dp"
    android:clickable="true"
    android:focusable="true"
    android:onClick="@{(v)-> clickHandler.onClick(v)}"
    android:orientation="vertical">
</LinearLayout>

6) Now handle click when your linearLayout clicked you can get click on interface which is implemented in action class.

@Override
void OnClick(View view){
    switch(view.getId()){
    case R.id.linearLayout:
        // Handler click and do some actions
        break;
    }
}

6) As mentioned above you can get layout click by data binding. Hope it will work for you.

Thanks

Happy Coding!!

回答2:

So everything was set up correctly and the generated bindings file shows the click listener being set up correctly, but for some very odd reason half the bindings were working and the newer ones weren't. By newer ones meaning the LinearLayout and all the attempts around it.

What solved the problem was a simple cache invalidation and respective restart and voila, the click listener is working perfectly on the LinearLayout. Just remember to set it clickable and focusable and any child views set as not clickable so they don't consume the event before the parent.

3 entire days around this one, took less than 10 minutes discussing with others here in the comments to remember trying to invalidate the cache of Android Studio, unbelievable of me...

回答3:

If Invalidate Cache does not work.

then Rebuild project from Build>Rebuild. Fix errors if any then Rebuild again.

来源：https://stackoverflow.com/questions/49579343/how-to-set-click-listener-to-linearlayout-using-data-binding

标签

android

data-binding

android-studio-3.0