Android开发-DesignDemo-AndroidStudio(八)CoordinatorDemo(3)

实现ActionBar隐藏显示，TextView悬停条目

记得styles.xml里，把主题设置为NoActionBar

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?><android.support.design.widget.CoordinatorLayout    xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    xmlns:app="http://schemas.android.com/apk/res-auto"    android:id="@+id/activity_main"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="com.iwanghang.coordinatordemo.MainActivity">    <!--enterAlwaysCollapsed 第一条上拉至第一条数据才出现ActionBar-->    <!--enterAlways 只要上拉就出现ActionBar-->    <android.support.design.widget.AppBarLayout        android:layout_width="match_parent"        android:layout_height="wrap_content"        app:theme="@style/Widget.AppCompat.ActionBar">        <android.support.v7.widget.Toolbar            android:id="@+id/toolbar"            android:layout_width="match_parent"            android:layout_height="?actionBarSize"            app:layout_scrollFlags="scroll|enterAlwaysCollapsed"/>        <TextView            android:text="悬停条目"            android:textColor="#ffffff"            android:layout_width="match_parent"            android:layout_height="wrap_content" />    </android.support.design.widget.AppBarLayout>    <android.support.v7.widget.RecyclerView        android:id="@+id/recycler_1"        app:layout_behavior="@string/appbar_scrolling_view_behavior"        android:layout_width="match_parent"        android:layout_height="match_parent"        app:layoutManager="LinearLayoutManager" />    <TextView        android:clickable="true"        android:id="@+id/textView_1"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginTop="100dp"        android:layout_marginLeft="100dp"        android:textSize="20sp"        android:background="#f00"        android:text="textView_1\nlist上下滚动显示隐藏\n通过setBehavior实现" />    <TextView        android:clickable="true"        android:id="@+id/textView_2"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_gravity="center"        android:textSize="20sp"        android:background="#f00"        android:text="textView_2\n向右滑动" />    <TextView        app:layout_behavior="com.iwanghang.coordinatordemo.MyBehavior"        android:clickable="true"        android:id="@+id/textView_3"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_gravity="center|bottom"        android:textSize="20sp"        android:background="#f00"        android:text="textView_3\nlist上下滚动显示隐藏\n指定layout_behavior实现" /></android.support.design.widget.CoordinatorLayout>

跟上一篇博文相比，java部分没有改变，以下是java部分。

Mainactivity.java:

package com.iwanghang.coordinatordemo;import android.support.design.widget.CoordinatorLayout;import android.support.design.widget.Snackbar;import android.support.design.widget.SwipeDismissBehavior;import android.support.v4.view.ViewCompat;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.support.v7.widget.RecyclerView;import android.support.v7.widget.Toolbar;import android.view.View;import android.widget.TextView;import java.util.ArrayList;import java.util.List;import java.util.Locale;public class MainActivity extends AppCompatActivity {    private TextView textView_1;    private TextView textView_2;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        textView_1 = (TextView) findViewById(R.id.textView_1);        textView_2 = (TextView) findViewById(R.id.textView_2);        // 手动强转控件类型        CoordinatorLayout.LayoutParams params_1 =                (CoordinatorLayout.LayoutParams) textView_1.getLayoutParams();        CoordinatorLayout.LayoutParams params_2 =                (CoordinatorLayout.LayoutParams) textView_2.getLayoutParams();        // setBehavior 设置控件的行为        //params.setBehavior();        // SwipeDismissBehavior 实例化滑动删除行为        SwipeDismissBehavior<View> behavior = new SwipeDismissBehavior<>();        // 滑动删除行为监听        behavior.setListener(new SwipeDismissBehavior.OnDismissListener() {            @Override            public void onDismiss(View view) { // 当控件消失                // 在设置控件隐藏之前，其实控件只是透明，还可以滑动回来                view.setVisibility(View.GONE); // 设置控件隐藏                Snackbar.make(view,"删除控件",Snackbar.LENGTH_LONG)                        .setAction("撤销", new View.OnClickListener() {                            @Override                            public void onClick(View view) {                                textView_2.setVisibility(View.VISIBLE); // 设置控件显示                                ViewCompat.animate(textView_2).alpha(1).start();                            }                        }).show();            }            @Override            public void onDragStateChanged(int state) { // 当控件停止            }        });        // 把滑动删除行为设置到textView控件上        params_2.setBehavior(behavior);        RecyclerView recycler_1 = (RecyclerView) findViewById(R.id.recycler_1);        List<String> list = new ArrayList<>();        for (int i = 0; i <100 ; i++) {            list.add(String.format(Locale.CHINA,"第%03d条数据",i+1));        }        recycler_1.setAdapter(new MyAdapter(this,list));        MyBehavior myBehavior = new MyBehavior();        params_1.setBehavior(myBehavior);        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);        setSupportActionBar(toolbar);    }}

MyAdapter.java:

package com.iwanghang.coordinatordemo;import android.content.Context;import android.support.v7.widget.RecyclerView;import android.view.ViewGroup;import android.widget.TextView;import java.util.List;public class MyAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>{    private Context context;    private List<String> list;    public MyAdapter(Context context, List<String> list) {        this.context = context;        this.list = list;    }    public Context getContext() {        return context;    }    public void setContext(Context context) {        this.context = context;    }    public List<String> getList() {        return list;    }    public void setList(List<String> list) {        this.list = list;    }    @Override    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {        TextView view = new TextView(context);        return new RecyclerView.ViewHolder(view){};    }    @Override    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {        ((TextView) holder.itemView).setText(list.get(position));    }    @Override    public int getItemCount() {        return list.size();    }}

MyBehavior.java:

package com.iwanghang.coordinatordemo;import android.content.Context;import android.support.design.widget.CoordinatorLayout;import android.support.v4.view.ViewCompat;import android.util.AttributeSet;import android.view.View;/** * 重写Behavior的方法 */public class MyBehavior extends CoordinatorLayout.Behavior {    /**     * 实现下面3行方法 则可以通过     * app:layout_behavior="com.iwanghang.coordinatordemo.MyBehavior"     * 来实现 MyBehavior     */    public MyBehavior(Context context, AttributeSet attrs) {        super(context, attrs);    }    public MyBehavior() {    }    // Behavior 开始滚动    @Override    public boolean onStartNestedScroll(CoordinatorLayout coordinatorLayout, View child, View directTargetChild, View target, int nestedScrollAxes) {        return true; // 为true，表示我们关心这个事件    }    // Behavior 正在滚动    @Override    public void onNestedPreScroll(CoordinatorLayout coordinatorLayout, View child, View target, int dx, int dy, int[] consumed) {        super.onNestedPreScroll(coordinatorLayout, child, target, dx, dy, consumed);        if (dy < 0){ // 向上滚动            ViewCompat.animate(child).scaleX(1).scaleY(1).start(); // 显示控件        }else { // 向下滚动            ViewCompat.animate(child).scaleX(0).scaleY(0).start(); // 隐藏控件        }    }}