android 5.0新特性学习--RecyclerView
在过去很多年,我们的PC或者手机设备都是采用拟物化的设计风格,IOS采用扁平化的特性,android在2014年IO大会上说采用Material Design的设计风格,显示效果不能过于生硬的转换,而是平滑,过度的切换方式,避免线性的动画效果,而是代替以曲线的效果进行展示,并且所有的图标的动画切换都应该无缝化切换。
如果想深入了解材料设计即(material Design)的设计:
可以参看如下网址:http://design.1sters.com,尤其是android 应用的UED设计师们,可以看下:
开发中要在libs文件夹下面中加上android_support_v4.jar包
RecyclerView
java.lang.Object
android.view.View
android.view.ViewGroup
android.support.v7.widget.RecyclerView
官网地址:https://developer.android.com/reference/android/support/v7/widget/RecyclerView.html
RecyclerView 一个特点就是,将 layout 抽象成了一个 LayoutManager,RecylerView 不负责子 View 的布局, 我们可以自定义 LayoutManager 来实现不同的布局效果, 目前只提供了LinearLayoutManager。 LinearLayoutManager 可以指定方向,默认是垂直, 可以指定水平, 这样就轻松实现了水平的 ListView。
除了LinearLayoutManager还有其他两种布局管理器:
GridLayoutManager 网格的item
StaggeredGridLayoutManager 交错的网格item
当然也可以通过集成ResyclerView,layoutManager类来自定义自己的布局管理器。
RecyclerView的使用过程中会使用到一个Adapter:RecyclerView.Adapter,里面屏蔽了以前写BaseAdapter的中好多重读的代码的编写,将加载item布局放在onCreateViewHolder(ViewGroup viewGroup, int i)方法中,在onBindViewHolder(ViewHolder viewHolder, int i)中数据加载到item中。用于优化的viewHolder也是继承自RecyclerView.ViewHolder。
RecyclerView不提供setOnItemClickListener方法,你可以在ViewHolder中添加事件。
RecyclerView之间的分割线:
http://my.oschina.net/xesam/blog/351408
官网地址:https://developer.android.com/reference/android/support/v7/widget/RecyclerView.Adapter.html
关于使用可以参考:
http://www.jcodecraeer.com/a/anzhuokaifa/androidkaifa/2014/0710/1631.html
http://blog.csdn.net/cym492224103/article/details/41719497
编写demo:
布局文件:
activity_main.xml
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.example.wangfubin.recyclerview.MainActivity"> <android.support.v7.widget.RecyclerView android:id="@+id/id_recyclerview" android:divider="#ffff0000" android:dividerHeight="10dp" android:layout_width="match_parent" android:layout_height="match_parent"/> </RelativeLayout>
item_gridview.xml:
<?xml version="1.0" encoding="utf-8"?> <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="100dp" xmlns:tool="http://schemas.android.com/tools" android:background="#44ff0000" android:layout_height="100dp"> <TextView android:id="@+id/id_num" android:layout_width="match_parent" android:layout_height="50dp" android:gravity="center" tool:text="1" /> </FrameLayout>
item_listview.xml
<?xml version="1.0" encoding="utf-8"?> <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" xmlns:tool="http://schemas.android.com/tools" android:background="#44ff0000" android:layout_height="wrap_content"> <TextView android:id="@+id/id_num" android:layout_width="match_parent" android:layout_height="50dp" android:gravity="center" tool:text="1" /> </FrameLayout>
MainActivity.java
import android.os.Bundle; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.DefaultItemAnimator; import android.support.v7.widget.RecyclerView; import android.support.v7.widget.StaggeredGridLayoutManager; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.widget.Toast; import java.util.ArrayList; import java.util.List; public class MainActivity extends AppCompatActivity { private RecyclerView mRecyclerView; private List<String> mDatas; private HomeAdapter mAdapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initData(); mRecyclerView = (RecyclerView) findViewById(R.id.id_recyclerview); //垂直线性RecyclerView //mRecyclerView.setLayoutManager(new LinearLayoutManager(this)); //Grid布局 //mRecyclerView.setLayoutManager(new GridLayoutManager(this,4)); //瀑布流 //垂直方向 //mRecyclerView.setLayoutManager(new StaggeredGridLayoutManager(4, StaggeredGridLayoutManager.VERTICAL)); //水平方向 mRecyclerView.setLayoutManager(new StaggeredGridLayoutManager(4, StaggeredGridLayoutManager.HORIZONTAL)); mRecyclerView.setAdapter(mAdapter = new HomeAdapter(getApplicationContext(),initData())); //垂直线性RecyclerView分割线 //mRecyclerView.addItemDecoration(new DividerItemDecoration(this, DividerItemDecoration.VERTICAL_LIST)); //GridView的分隔线 mRecyclerView.addItemDecoration(new DividerGridItemDecoration(this)); //添加默认动画 mRecyclerView.setItemAnimator(new DefaultItemAnimator()); mAdapter.setOnItemClickLitener(new HomeAdapter.OnItemClickLitener() { @Override public void onItemClick(View view, int position) { Toast.makeText(getApplicationContext(),"单击事件",Toast.LENGTH_SHORT).show(); } @Override public void onItemLongClick(View view, int position) { Toast.makeText(getApplicationContext(),"长按事件",Toast.LENGTH_SHORT).show(); } }); } /** * 初始化模拟数据 * @return */ protected List<String> initData() { mDatas = new ArrayList<String>(); for (int i = 'A'; i < 'z'; i++) { mDatas.add("" + (char) i); } return mDatas; } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.main, menu); return super.onCreateOptionsMenu(menu); } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case R.id.id_action_add: //新增数据 mAdapter.addData(1); break; case R.id.id_action_delete: //删除数据 mAdapter.removeData(1); break; } return true; } }
HomeAdapter.java
import java.util.List; 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; /** * Created by wangfubin on 2016/11/12. */ class HomeAdapter extends RecyclerView.Adapter<HomeAdapter.MyViewHolder> { private List<String> mDatas; private LayoutInflater mInflater; public interface OnItemClickLitener { void onItemClick(View view, int position); void onItemLongClick(View view , int position); } private OnItemClickLitener mOnItemClickLitener; public void setOnItemClickLitener(OnItemClickLitener mOnItemClickLitener) { this.mOnItemClickLitener = mOnItemClickLitener; } public HomeAdapter(Context context, List<String> datas) { mInflater = LayoutInflater.from(context); mDatas = datas; } @Override public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { MyViewHolder holder = new MyViewHolder(mInflater.inflate( R.layout.item_listview, parent, false)); return holder; } @Override public void onBindViewHolder(final MyViewHolder holder, final int position) { holder.tv.setText(mDatas.get(position)); // 如果设置了回调,则设置点击事件 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 addData(int position) { mDatas.add(position, "Insert One"); notifyItemInserted(position); } 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); } } }
DividerItemDecoration.java
/** * 垂直水平分割线 */ public class DividerItemDecoration extends RecyclerView.ItemDecoration { private static final int[] ATTRS = new int[]{ android.R.attr.listDivider }; public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL; public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL; private Drawable mDivider; private int mOrientation; public DividerItemDecoration(Context context, int orientation) { final TypedArray a = context.obtainStyledAttributes(ATTRS); mDivider = a.getDrawable(0); a.recycle(); setOrientation(orientation); } public void setOrientation(int orientation) { if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST) { throw new IllegalArgumentException("invalid orientation"); } mOrientation = orientation; } @Override public void onDraw(Canvas c, RecyclerView parent) { Log.v("recyclerview - itemdecoration", "onDraw()"); if (mOrientation == VERTICAL_LIST) { drawVertical(c, parent); } else { drawHorizontal(c, parent); } } public void drawVertical(Canvas c, RecyclerView parent) { final int left = parent.getPaddingLeft(); final int right = parent.getWidth() - parent.getPaddingRight(); final int childCount = parent.getChildCount(); for (int i = 0; i < childCount; i++) { final View child = parent.getChildAt(i); android.support.v7.widget.RecyclerView v = new android.support.v7.widget.RecyclerView(parent.getContext()); final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child .getLayoutParams(); final int top = child.getBottom() + params.bottomMargin; final int bottom = top + mDivider.getIntrinsicHeight(); mDivider.setBounds(left, top, right, bottom); mDivider.draw(c); } } public void drawHorizontal(Canvas c, RecyclerView parent) { final int top = parent.getPaddingTop(); final int bottom = parent.getHeight() - parent.getPaddingBottom(); final int childCount = parent.getChildCount(); for (int i = 0; i < childCount; i++) { final View child = parent.getChildAt(i); final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child .getLayoutParams(); final int left = child.getRight() + params.rightMargin; final int right = left + mDivider.getIntrinsicHeight(); mDivider.setBounds(left, top, right, bottom); mDivider.draw(c); } } @Override public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent) { if (mOrientation == VERTICAL_LIST) { outRect.set(0, 0, 0, mDivider.getIntrinsicHeight()); } else { outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0); } } }
DividerGridItemDecoration.java
import android.content.Context; import android.content.res.TypedArray; import android.graphics.Canvas; import android.graphics.Rect; import android.graphics.drawable.Drawable; import android.support.v7.widget.GridLayoutManager; import android.support.v7.widget.RecyclerView; import android.support.v7.widget.RecyclerView.LayoutManager; import android.support.v7.widget.RecyclerView.State; import android.support.v7.widget.StaggeredGridLayoutManager; import android.view.View; /** *GridView分割线 * @author zhy * */ public class DividerGridItemDecoration extends RecyclerView.ItemDecoration { private static final int[] ATTRS = new int[] { android.R.attr.listDivider }; private Drawable mDivider; public DividerGridItemDecoration(Context context) { final TypedArray a = context.obtainStyledAttributes(ATTRS); mDivider = a.getDrawable(0); a.recycle(); } @Override public void onDraw(Canvas c, RecyclerView parent, State state) { drawHorizontal(c, parent); drawVertical(c, parent); } private int getSpanCount(RecyclerView parent) { // 列数 int spanCount = -1; LayoutManager layoutManager = parent.getLayoutManager(); if (layoutManager instanceof GridLayoutManager) { spanCount = ((GridLayoutManager) layoutManager).getSpanCount(); } else if (layoutManager instanceof StaggeredGridLayoutManager) { spanCount = ((StaggeredGridLayoutManager) layoutManager) .getSpanCount(); } return spanCount; } public void drawHorizontal(Canvas c, RecyclerView parent) { int childCount = parent.getChildCount(); for (int i = 0; i < childCount; i++) { final View child = parent.getChildAt(i); final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child .getLayoutParams(); final int left = child.getLeft() - params.leftMargin; final int right = child.getRight() + params.rightMargin + mDivider.getIntrinsicWidth(); final int top = child.getBottom() + params.bottomMargin; final int bottom = top + mDivider.getIntrinsicHeight(); mDivider.setBounds(left, top, right, bottom); mDivider.draw(c); } } public void drawVertical(Canvas c, RecyclerView parent) { final int childCount = parent.getChildCount(); for (int i = 0; i < childCount; i++) { final View child = parent.getChildAt(i); final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child .getLayoutParams(); final int top = child.getTop() - params.topMargin; final int bottom = child.getBottom() + params.bottomMargin; final int left = child.getRight() + params.rightMargin; final int right = left + mDivider.getIntrinsicWidth(); mDivider.setBounds(left, top, right, bottom); mDivider.draw(c); } } private boolean isLastColum(RecyclerView parent, int pos, int spanCount, int childCount) { LayoutManager layoutManager = parent.getLayoutManager(); if (layoutManager instanceof GridLayoutManager) { if ((pos + 1) % spanCount == 0)// 如果是最后一列,则不需要绘制右边 { return true; } } else if (layoutManager instanceof StaggeredGridLayoutManager) { int orientation = ((StaggeredGridLayoutManager) layoutManager) .getOrientation(); if (orientation == StaggeredGridLayoutManager.VERTICAL) { if ((pos + 1) % spanCount == 0)// 如果是最后一列,则不需要绘制右边 { return true; } } else { childCount = childCount - childCount % spanCount; if (pos >= childCount)// 如果是最后一列,则不需要绘制右边 return true; } } return false; } private boolean isLastRaw(RecyclerView parent, int pos, int spanCount, int childCount) { LayoutManager layoutManager = parent.getLayoutManager(); if (layoutManager instanceof GridLayoutManager) { childCount = childCount - childCount % spanCount; if (pos >= childCount)// 如果是最后一行,则不需要绘制底部 return true; } else if (layoutManager instanceof StaggeredGridLayoutManager) { int orientation = ((StaggeredGridLayoutManager) layoutManager) .getOrientation(); // StaggeredGridLayoutManager 且纵向滚动 if (orientation == StaggeredGridLayoutManager.VERTICAL) { childCount = childCount - childCount % spanCount; // 如果是最后一行,则不需要绘制底部 if (pos >= childCount) return true; } else // StaggeredGridLayoutManager 且横向滚动 { // 如果是最后一行,则不需要绘制底部 if ((pos + 1) % spanCount == 0) { return true; } } } return false; } @Override public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent) { int spanCount = getSpanCount(parent); int childCount = parent.getAdapter().getItemCount(); if (isLastRaw(parent, itemPosition, spanCount, childCount))// 如果是最后一行,则不需要绘制底部 { outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0); } else if (isLastColum(parent, itemPosition, spanCount, childCount))// 如果是最后一列,则不需要绘制右边 { outRect.set(0, 0, 0, mDivider.getIntrinsicHeight()); } else { outRect.set(0, 0, mDivider.getIntrinsicWidth(), mDivider.getIntrinsicHeight()); } } }
效果: