在上篇部落格 CoordinatorLayout、AppBarLayout實現上滑隱藏圖片，下滑顯示圖片的基礎上，仿掘金app首介面，向上滑動隱藏FloatingActionButton，向下滑動顯示FloatingActionButton的效果。
layout_fab_button.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:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<android.support.design.widget.AppBarLayout
android:id="@+id/app_bar_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.design.widget.CollapsingToolbarLayout
android:id="@+id/collapsing_toolbar_layout"
android:layout_width="match_parent"
android:layout_height="240dp"
app:contentScrim="@color/colorPrimary"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="centerCrop"
android:src="@mipmap/splash"
app:layout_collapseMode="parallax"/>
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:layout_collapseMode="pin"
app:navigationIcon="@mipmap/back"
app:title="keep"
app:titleTextColor="@color/white"/>
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v7.widget.RecyclerView
android:id="@+id/id_recyclerview"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_behavior="@string/appbar_scrolling_view_behavior"/>
<android.support.design.widget.FloatingActionButton
android:id="@+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="15dp"
android:layout_marginRight="15dp"
android:src="@mipmap/ic_book_list"
app:elevation="4dp"
app:layout_anchor="@+id/id_recyclerview"
app:layout_anchorGravity="right|bottom"
app:layout_behavior="com.zhoujian.mykeep.behavior.BehaviorDefault"/>
</android.support.design.widget.CoordinatorLayout>複製程式碼BehaviorDefault.java
package com.zhoujian.mykeep.behavior;
import android.content.Context;
import android.support.design.widget.CoordinatorLayout;
import android.support.design.widget.FloatingActionButton;
import android.support.v4.view.ViewCompat;
import android.util.AttributeSet;
import android.view.View;
/**
* Created by zhoujian on 2017/3/15.
*/
public class BehaviorDefault extends FloatingActionButton.Behavior {
public BehaviorDefault(Context context, AttributeSet attrs) {
super();
}
@Override
public boolean onStartNestedScroll(final CoordinatorLayout coordinatorLayout, final FloatingActionButton child,
final View directTargetChild, final View target, final int nestedScrollAxes)
{
return nestedScrollAxes == ViewCompat.SCROLL_AXIS_VERTICAL
|| super.onStartNestedScroll(coordinatorLayout, child, directTargetChild, target, nestedScrollAxes);
}
@Override
public void onNestedScroll(final CoordinatorLayout coordinatorLayout, final FloatingActionButton child,
final View target, final int dxConsumed, final int dyConsumed,
final int dxUnconsumed, final int dyUnconsumed)
{
super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed);
if (dyConsumed > 0 && child.getVisibility() == View.VISIBLE)
{
child.hide();
} else if (dyConsumed < 0 && child.getVisibility() != View.VISIBLE)
{
child.show();
}
}
}複製程式碼FAButtonActivity.java
package com.zhoujian.mykeep.activity;
import android.graphics.Color;
import android.os.Bundle;
import android.support.design.widget.AppBarLayout;
import android.support.design.widget.CollapsingToolbarLayout;
import android.support.design.widget.FloatingActionButton;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.DividerItemDecoration;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.MenuItem;
import android.view.View;
import android.widget.Toast;
import com.zhoujian.mykeep.R;
import com.zhoujian.mykeep.adapter.MainAdapter;
import com.zhoujian.mykeep.bean.Person;
import java.util.ArrayList;
/**
* Created by zhoujian on 2017/3/15.
*/
public class FAButtonActivity extends AppCompatActivity {
public static final String TAG = "ModeActivity";
private RecyclerView mRecyclerView;
private ArrayList<Person> personList;
private MainAdapter adapter;
@Override
protected void onCreate( Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.layout_fab_button);
initData();
initView();
}
private void initData()
{
personList = new ArrayList<Person>();
Person mPerson0= new Person("林黛玉");
personList.add(mPerson0);
Person mPerson1= new Person("薛寶釵");
personList.add(mPerson1);
Person mPerson2= new Person("賈元春");
personList.add(mPerson2);
Person mPerson3= new Person("賈迎春");
personList.add(mPerson3);
Person mPerson4= new Person("賈探春");
personList.add(mPerson4);
Person mPerson5= new Person("賈惜春");
personList.add(mPerson5);
Person mPerson6= new Person("史湘雲");
personList.add(mPerson6);
Person mPerson7= new Person("王熙鳳");
personList.add(mPerson7);
Person mPerson8= new Person("秦可卿");
personList.add(mPerson8);
Person mPerson9= new Person("賈寶玉");
personList.add(mPerson9);
}
private void initView()
{
final Toolbar toolbar = (Toolbar)findViewById(R.id.toolbar);
toolbar.setTitleTextColor(Color.TRANSPARENT);
toolbar.inflateMenu(R.menu.menu_search);
toolbar.setNavigationOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
finish();
}
});
toolbar.setOnMenuItemClickListener(new Toolbar.OnMenuItemClickListener() {
@Override
public boolean onMenuItemClick(MenuItem item) {
switch (item.getItemId()){
case R.id.item_search:
//點選設定
Toast.makeText(FAButtonActivity.this, "按鈕被點選了", Toast.LENGTH_SHORT).show();
break;
}
return false;
}
});
AppBarLayout app_bar_layout = (AppBarLayout)findViewById(R.id.app_bar_layout);
final CollapsingToolbarLayout collapsing_toolbar_layout = (CollapsingToolbarLayout)findViewById(R.id.collapsing_toolbar_layout);
collapsing_toolbar_layout.setTitle("");
collapsing_toolbar_layout.setCollapsedTitleTextColor(getResources().getColor(R.color.white));
collapsing_toolbar_layout.setExpandedTitleColor(getResources().getColor(R.color.white));
collapsing_toolbar_layout.setExpandedTitleColor(Color.TRANSPARENT);
app_bar_layout.addOnOffsetChangedListener(new AppBarLayout.OnOffsetChangedListener() {
@Override
public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {
Log.e(TAG,"appBarLayoutHeight:"+appBarLayout.getHeight()+" getTotalScrollRange:"+appBarLayout.getTotalScrollRange()+" offSet:"+verticalOffset);
if(Math.abs(verticalOffset) >= appBarLayout.getTotalScrollRange()){
toolbar.setTitleTextColor(getResources().getColor(R.color.white));
collapsing_toolbar_layout.setTitle("keep");
}else{
collapsing_toolbar_layout.setTitle("");
}
}
});
FloatingActionButton fab= (FloatingActionButton)findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(FAButtonActivity.this, "FloatingActionButton被點選了", Toast.LENGTH_SHORT).show();
}
});
mRecyclerView =(RecyclerView) findViewById(R.id.id_recyclerview);
adapter = new MainAdapter(FAButtonActivity.this, personList);
mRecyclerView.setLayoutManager(new LinearLayoutManager(FAButtonActivity.this));
mRecyclerView.addItemDecoration(new DividerItemDecoration(FAButtonActivity.this,DividerItemDecoration.VERTICAL));
// 設定item動畫
mRecyclerView.setItemAnimator(new DefaultItemAnimator());
mRecyclerView.setAdapter(adapter);
}
}複製程式碼MainAdapter.java
package com.zhoujian.mykeep.adapter;
import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.RecyclerView.ViewHolder;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnLongClickListener;
import android.view.ViewGroup;
import android.widget.TextView;
import com.zhoujian.mykeep.R;
import com.zhoujian.mykeep.bean.Person;
import java.util.ArrayList;
public class MainAdapter extends RecyclerView.Adapter<MainAdapter.MyViewHolder>
{
private ArrayList<Person> mDatas;
private LayoutInflater mInflater;
private OnItemClickLitener mOnItemClickLitener;
public interface OnItemClickLitener
{
void onItemClick(View view, int position);
void onItemLongClick(View view, int position);
}
public void setOnItemClickLitener(OnItemClickLitener mOnItemClickLitener)
{
this.mOnItemClickLitener = mOnItemClickLitener;
}
public MainAdapter(Context context, ArrayList<Person> datas)
{
mInflater = LayoutInflater.from(context);
mDatas = datas;
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType)
{
MyViewHolder holder = new MyViewHolder(mInflater.inflate(
R.layout.item_home, parent, false));
return holder;
}
@Override
public void onBindViewHolder(final MyViewHolder holder, final int position)
{
holder.tv.setText(mDatas.get(position).getName());
// 如果設定了回撥，則設定點選事件
if (mOnItemClickLitener != null)
{
holder.itemView.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v)
{
int pos = holder.getLayoutPosition();
mOnItemClickLitener.onItemClick(holder.itemView, pos);
}
});
holder.itemView.setOnLongClickListener(new OnLongClickListener()
{
@Override
public boolean onLongClick(View v)
{
int pos = holder.getLayoutPosition();
mOnItemClickLitener.onItemLongClick(holder.itemView, pos);
removeData(pos);
return false;
}
});
}
}
@Override
public int getItemCount()
{
return mDatas.size();
}
public void removeData(int position)
{
mDatas.remove(position);
notifyItemRemoved(position);
}
class MyViewHolder extends ViewHolder
{
TextView tv;
public MyViewHolder(View view)
{
super(view);
tv = (TextView) view.findViewById(R.id.id_num);
}
}
}複製程式碼