Android Material Design：基于CoordinatorLayout实现向上滚动导航条ToolBar滚出、向下滚动导航条滚出

我会带着你远行 2023-10-16 22:20 30阅读 0赞

**Android Material Design：基于CoordinatorLayout实现向上滚动导航条ToolBar滚出、向下滚动导航条滚出**

要实现的效果：  
一个导航条和一个ToolBar，初始状态：

![Center][]

手指在屏幕向上滑动时候的效果，ToolBar滚出：

![Center 1][]

当手指在屏幕向下滑动时候，ToolBar又滚出：

![Center 2][]

实现上述效果要使用Android Material Design引入的CoordinatorLayout。关键地方有两点：

（1）设置app:layout\_scrollFlags="scroll|enterAlways"。  
如果打算将某个View实现滑入滑出，则需要在此View的属性中定义。在本例中是ToolBar。  
（2）同时要设置触发（1）View的滚动组件的一个属性app:layout\_behavior="@string/appbar\_scrolling\_view\_behavior"  
比如在本例中，ToolBar下方是一个TabLayout，TabLayout下方是是一个RecyclerView，意图是RecyclerView在向上、向下滚动时候，自动触发ToolBar滚出或者滚入。

现在给出完整例子加以说明。  
MainActivity.java :

package zhangphil.view;
    
    import android.app.Activity;
    import android.os.Bundle;
    import android.support.design.widget.TabLayout;
    import android.support.v7.widget.LinearLayoutManager;
    import android.support.v7.widget.RecyclerView;
    import android.support.v7.widget.Toolbar;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.LinearLayout;
    import android.widget.TextView;
    
    public class MainActivity extends Activity {
    
    	@Override
    	protected void onCreate(Bundle savedInstanceState) {
    		super.onCreate(savedInstanceState);
    		setContentView(R.layout.activity_main);
    
    		Toolbar mToolbar = (Toolbar) findViewById(R.id.toolBar);
    		mToolbar.setLogo(R.drawable.ic_launcher);
    		mToolbar.setNavigationIcon(android.R.drawable.ic_menu_delete);
    		mToolbar.setTitle("zhangphil");
    		mToolbar.setSubtitle("zhangphil副标题");
    
    		TabLayout tabLayout = (TabLayout) findViewById(R.id.tabLayout);
    		for (int i = 0; i < 10; i++)
    			tabLayout.addTab(tabLayout.newTab().setText("选项卡槽" + i));
    		tabLayout.setTabMode(TabLayout.MODE_SCROLLABLE);
    
    		RecyclerView mRecyclerView = (RecyclerView) findViewById(R.id.recyclerView);
    		LinearLayoutManager mLayoutManager = new LinearLayoutManager(this);
    		mLayoutManager.setOrientation(LinearLayout.VERTICAL);
    		mRecyclerView.setLayoutManager(mLayoutManager);
    		RecyclerView.Adapter mAdapter = new MyRecyclerViewAdapter(this);
    		mRecyclerView.setAdapter(mAdapter);
    	}
    
    	public class MyRecyclerViewAdapter extends RecyclerView.Adapter<MyViewHolder> {
    
    		private	LayoutInflater mLayoutInflater;
    		
    		public MyRecyclerViewAdapter(Activity activity) {
    			super();
    			mLayoutInflater=activity.getLayoutInflater();
    		}
    
    		@Override
    		public MyViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
    
    			View v = mLayoutInflater.inflate(android.R.layout.simple_list_item_1, null);
    			MyViewHolder holder = new MyViewHolder(v);
    			return holder;
    		}
    
    		@Override
    		public void onBindViewHolder(MyViewHolder viewHolder, int pos) {
    			viewHolder.text.setText("数据" + pos);
    		}
    
    		@Override
    		public int getItemCount() {
    			return 100;
    		}
    	}
    
    	private class MyViewHolder extends RecyclerView.ViewHolder {
    		public TextView text;
    
    		public MyViewHolder(View itemView) {
    			super(itemView);
    			text=(TextView) itemView.findViewById(android.R.id.text1);
    		}
    	}
    }

MainActivity.java的布局文件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:app="http://schemas.android.com/apk/res-auto"
        android:id="@+id/main_content"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:fitsSystemWindows="true" >
    
        <android.support.design.widget.AppBarLayout
            android:id="@+id/appbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" >
    
            <android.support.v7.widget.Toolbar
                android:id="@+id/toolBar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                app:layout_scrollFlags="scroll|enterAlways"
                android:background="#2196f3"
                android:minHeight="?attr/actionBarSize" >
    
                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="一个TextView" />
            </android.support.v7.widget.Toolbar>
    
            <android.support.design.widget.TabLayout
                android:id="@+id/tabLayout"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:background="#e0e0e0"
                app:tabIndicatorColor="#ef5350"
                app:tabSelectedTextColor="#1976d2"
                app:tabTextColor="#90caf9" />
        </android.support.design.widget.AppBarLayout>
    
        <android.support.v7.widget.RecyclerView
            android:id="@+id/recyclerView"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_behavior="@string/appbar_scrolling_view_behavior" />
    
        <android.support.design.widget.FloatingActionButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="bottom|end"
            android:src="@drawable/ic_launcher" />
    
    </android.support.design.widget.CoordinatorLayout>

代码运行结果本文开始的三张图示内容。

[Center]: https://img-blog.csdn.net/20151003124054479?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center
[Center 1]: https://img-blog.csdn.net/20151003124115365?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center
[Center 2]: https://img-blog.csdn.net/20151003124135033?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center