Android--CoordinatorLayout基本使用

aruba

发布于 2020-07-03 11:33:47

9420

发布于 2020-07-03 11:33:47

CoordinatorLayout是在desgin包下的一个用于协调子控件的组件，可以解决绝大部分滑动联动问题，使用方法也很简单，为观察者注册一个Behavior，在Behavior指定要监听的控件（可以多个）

这边实现一个TextView随着另一个TextView的移动而移动

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/tv_obed"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="被观察者"
        android:textSize="18sp" />

    <TextView
        android:id="@+id/tv_ob"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="观察者"
        android:textSize="18sp"
        app:layout_behavior="com.aruba.coordinatorlayoutapplication.MyBehavior" />

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

public class MyBehavior extends CoordinatorLayout.Behavior {

    /**
     * 注意：一定要写这个构造方法，因为是CoordinatorLayout反射要用到
     *
     * @param context
     * @param attrs
     */
    public MyBehavior(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    /**
     * 确定要监听哪个控件
     *
     * @param parent
     * @param child
     * @param dependency
     * @return
     */
    @Override
    public boolean layoutDependsOn(@NonNull CoordinatorLayout parent, @NonNull View child, @NonNull View dependency) {
        if (dependency.getId() == R.id.tv_obed)//监听我们的被观察者
            return true;

        return false;
    }

    /**
     * 被监听的控件发生的改变，则会回调此方法
     *
     * @param parent
     * @param child
     * @param dependency
     * @return
     */
    @Override
    public boolean onDependentViewChanged(@NonNull CoordinatorLayout parent, @NonNull View child, @NonNull View dependency) {
        child.setY(dependency.getY() + dependency.getHeight());//将观察者view放在被监听的控件的下面
        child.setX(dependency.getX());

        return true;
    }

}

public class MainActivity extends AppCompatActivity {
    private TextView tvObed;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        tvObed = findViewById(R.id.tv_obed);
        //被观察者随着手指的移动而移动
        tvObed.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                tvObed.setX(event.getRawX());
                tvObed.setY(event.getRawY());
                return true;
            }
        });
    }
}

最后效果：

此外FloatingActionButton拥有自己封装好的Behavior，下面结合RecyclerView进行使用

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".FloatingActivity">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recyclerview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"></android.support.v7.widget.RecyclerView>

    <android.support.design.widget.FloatingActionButton
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|right"
        android:src="@drawable/ic_add_24dp"
        app:borderWidth="0dp"
        app:layout_behavior=".FloatingBehavior" />

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

public class FloatingBehavior extends FloatingActionButton.Behavior {
    private ValueAnimator valueAnimator;
    private boolean isReverse;

    public FloatingBehavior(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    /**
     * 设置我们需要监听的滑动，横向还是竖直
     *
     * @param coordinatorLayout
     * @param child
     * @param directTargetChild
     * @param target
     * @param axes
     * @param type
     * @return
     */
    @Override
    public boolean onStartNestedScroll(@NonNull CoordinatorLayout coordinatorLayout, @NonNull FloatingActionButton child, @NonNull View directTargetChild, @NonNull View target, int axes, int type) {
        //只关注竖直滑动
        return axes == ViewCompat.SCROLL_AXIS_VERTICAL;
    }

    /**
     * 滑动控件有滑动的时候，会回调这个方法
     *
     * @param coordinatorLayout
     * @param child
     * @param target
     * @param dxConsumed
     * @param dyConsumed
     * @param dxUnconsumed
     * @param dyUnconsumed
     * @param type
     */
    @Override
    public void onNestedScroll(@NonNull CoordinatorLayout coordinatorLayout, @NonNull FloatingActionButton child, @NonNull View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed, int type) {
        createValueAnimator(child);

        if (dyConsumed > 0 && child.getVisibility() == View.VISIBLE) {//滑动控件往下滚动
            animeOut();
        } else if (dyConsumed < 0 && child.getVisibility() == View.INVISIBLE) {
            child.setVisibility(View.VISIBLE);
            animeIn();
        }
        super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed, type);
    }

    private void animeIn() {
        if (valueAnimator == null || valueAnimator.isRunning()) {
            return;
        }

        valueAnimator.reverse();
        isReverse = true;
    }

    private void animeOut() {
        if (valueAnimator == null || valueAnimator.isRunning()) {
            return;
        }

        valueAnimator.start();
        isReverse = false;
    }

    public void createValueAnimator(final FloatingActionButton child) {
        if (valueAnimator == null) {
            valueAnimator = ValueAnimator.ofFloat(1f);
            valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
                @Override
                public void onAnimationUpdate(ValueAnimator animation) {
                    float fraction = animation.getAnimatedFraction();
                    child.setScaleX(1 - fraction);
                    child.setScaleY(1 - fraction);
                }
            });
            valueAnimator.addListener(new AnimatorListenerAdapter() {
                @Override
                public void onAnimationEnd(Animator animation) {
                    if (!isReverse) {
                        child.setVisibility(View.INVISIBLE);
                    }
                    super.onAnimationEnd(animation);
                }
            });
            valueAnimator.setDuration(1000);
        }
    }
}

public class FloatingActivity extends AppCompatActivity {
    private RecyclerView recyclerview;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_floating);

        recyclerview = findViewById(R.id.recyclerview);
        recyclerview.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false));
        MyAdapter myAdapter = new MyAdapter();
        recyclerview.setAdapter(myAdapter);
    }

    class MyAdapter extends RecyclerView.Adapter {

        @NonNull
        @Override
        public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
            TextView textView = new TextView(viewGroup.getContext());
            textView.setLayoutParams(new RecyclerView.LayoutParams(RecyclerView.LayoutParams.MATCH_PARENT, RecyclerView.LayoutParams.MATCH_PARENT));
            textView.setTextSize(30);
            textView.setGravity(Gravity.CENTER);
            RecyclerView.ViewHolder viewHolder = new ViewHolder(textView);
            return viewHolder;
        }

        @Override
        public void onBindViewHolder(@NonNull RecyclerView.ViewHolder viewHolder, int i) {
            ((TextView) viewHolder.itemView).setText(String.valueOf(i + 1));
        }

        @Override
        public int getItemCount() {
            return 20;
        }

        class ViewHolder extends RecyclerView.ViewHolder {

            public ViewHolder(@NonNull View itemView) {
                super(itemView);
            }
        }

    }
}