Android5.x新特性之RecyclerGridView

activity_single_recyclerview.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

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

</RelativeLayout>

item_home.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="#44ff0000" >

    <TextView
        android:id="@+id/id_num"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_gravity="center"
        android:gravity="center"
        android:text="1" />

</FrameLayout>

</pre><pre name="code" class="html">  <style name="AppTheme" parent="AppBaseTheme">

        <!-- All customizations that are NOT specific to a particular API-level can go here. -->
        <item name="android:listDivider">@drawable/divider_bg</item>
    </style>

divider_bg.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle" >
    <size android:width="5dp" android:height="5dp"/>
    <solid android:color="#ffffff"/>

</shape>

MainActivity

package com.example.demo;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.RecyclerView.ViewHolder;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class MainActivity extends Activity {

	private RecyclerView mRecyclerView;
	private List<String> mDatas;
	private HomeAdapter mAdapter;

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

		initData();
		mRecyclerView = (RecyclerView) findViewById(R.id.id_recyclerview);
		mRecyclerView.setLayoutManager(new GridLayoutManager(this, 4));
		mRecyclerView.setAdapter(mAdapter = new HomeAdapter());

		/**
		 * 分割线
		 */
		mRecyclerView.addItemDecoration(new DividerGridItemDecoration(this));
	}

	protected void initData() {
		mDatas = new ArrayList<String>();
		for (int i = 'A'; i < 'z'; i++) {
			mDatas.add("" + (char) i);
		}
	}

	class HomeAdapter extends RecyclerView.Adapter<HomeAdapter.MyViewHolder> {

		@Override
		public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
			MyViewHolder holder = new MyViewHolder(LayoutInflater.from(
					MainActivity.this).inflate(R.layout.item_home, parent,
					false));
			return holder;
		}

		@Override
		public void onBindViewHolder(MyViewHolder holder, int position) {
			holder.tv.setText(mDatas.get(position));
		}

		@Override
		public int getItemCount() {
			return mDatas.size();
		}

		class MyViewHolder extends ViewHolder {

			TextView tv;

			public MyViewHolder(View view) {
				super(view);
				tv = (TextView) view.findViewById(R.id.id_num);
			}
		}
	}

}

DividerGridItemDecoration

package com.example.demo;

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.util.Log;
import android.view.View;

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);

	}

	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);
		}
	}

	/***************************************************/

	// public void drawVertical(Canvas c, RecyclerView parent) {
	// final int left = parent.getPaddingLeft();
	// final int right = parent.getWidth() - parent.getPaddingRight();
	// //得到条目的数量
	// final int childCount = parent.getChildCount();
	//
	// for (int i = 0; i < childCount; i++) {
	// //得到
	// final View child = parent.getChildAt(i);
	// 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) {
		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());
		}
	}

	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;
	}

	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;
	}

}