FloatingActionButton奇怪的按压行为(FloatingActionButton strange press behavior)

 我不知道是什么突然造成这种情况，因为我认为我没有改变任何代码（也许这是Android Studio 2.0的错误？）。 
 
 但是现在当我按下FloatingActionButton时，它会保持按下状态，当我第一次点击它时它什么都不做。 如果我再次开始点击它，它似乎工作（但仍然看起来很紧张）。 
 
 在我的OnCreate方法中： 
 
    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    assert fab != null;

    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
           //does stuff here, behavior is the same even if I remove this code
        }
    });
 
 XML： 
 
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">



    <android.support.design.widget.CoordinatorLayout
        android:id="@+id/coordinator_layout"
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <android.support.design.widget.FloatingActionButton
            android:id="@+id/fab"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="bottom|end"
            android:layout_margin="@dimen/fab_margin"
            android:src="@android:drawable/ic_input_add"
            android:baselineAlignBottom="false"
            android:focusableInTouchMode="true"
            />

    </android.support.design.widget.CoordinatorLayout>

</LinearLayout>

I have no idea what suddenly caused this, as I don't think I've changed any code (maybe this is an Android Studio 2.0 bug?).
 
But now when I press a FloatingActionButton, it stays pressed and doesn't do anything when I first click it. If I start clicking it again, it seems to work (but still looks pressed).
 
In my OnCreate method:
 
    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    assert fab != null;

    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
           //does stuff here, behavior is the same even if I remove this code
        }
    });
 
XML:
 
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">



    <android.support.design.widget.CoordinatorLayout
        android:id="@+id/coordinator_layout"
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <android.support.design.widget.FloatingActionButton
            android:id="@+id/fab"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="bottom|end"
            android:layout_margin="@dimen/fab_margin"
            android:src="@android:drawable/ic_input_add"
            android:baselineAlignBottom="false"
            android:focusableInTouchMode="true"
            />

    </android.support.design.widget.CoordinatorLayout>

</LinearLayout>

原文：https://stackoverflow.com/questions/36705749