googles示例RecyclerView

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/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*      http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

package com.example.android.recyclerview;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.RadioButton;

/**
 * Demonstrates the use of {@link RecyclerView} with a {@link LinearLayoutManager} and a
 * {@link GridLayoutManager}.
 */
public class RecyclerViewFragment extends Fragment {

    private static final String TAG = "RecyclerViewFragment";
    private static final String KEY_LAYOUT_MANAGER = "layoutManager";
    private static final int SPAN_COUNT = 2;
    private static final int DATASET_COUNT = 60;

    /**
     * 布局管理器的类型，Linear的和Grid的
     */
    private enum LayoutManagerType {
        GRID_LAYOUT_MANAGER,
        LINEAR_LAYOUT_MANAGER
    }

    protected LayoutManagerType mCurrentLayoutManagerType;

    protected RadioButton mLinearLayoutRadioButton;
    protected RadioButton mGridLayoutRadioButton;

    protected RecyclerView mRecyclerView;
    protected CustomAdapter mAdapter;
    protected RecyclerView.LayoutManager mLayoutManager;
    protected String[] mDataset;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Initialize dataset, this data would usually come from a local content provider or
        // remote server.
        initDataset();
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.recycler_view_frag, container, false);
        rootView.setTag(TAG);

        // BEGIN_INCLUDE(initializeRecyclerView)
        mRecyclerView = (RecyclerView) rootView.findViewById(R.id.recyclerView);

        // LinearLayoutManager is used here, this will layout the elements in a similar fashion
        // to the way ListView would layout elements. The RecyclerView.LayoutManager defines how
        // elements are laid out.
        //这里线性布局管理器被是使用，这将类似于ListView放置元素的方式，RecyclerView.LayoutManager定义了元素的放置方式
        mLayoutManager = new LinearLayoutManager(getActivity());

        mCurrentLayoutManagerType = LayoutManagerType.LINEAR_LAYOUT_MANAGER;

        if (savedInstanceState != null) {
            // Restore saved layout manager type.
            mCurrentLayoutManagerType = (LayoutManagerType) savedInstanceState
                    .getSerializable(KEY_LAYOUT_MANAGER);
        }
        setRecyclerViewLayoutManager(mCurrentLayoutManagerType);

        mAdapter = new CustomAdapter(mDataset);
        // Set CustomAdapter as the adapter for RecyclerView.
        mRecyclerView.setAdapter(mAdapter);
        // END_INCLUDE(initializeRecyclerView)

        mLinearLayoutRadioButton = (RadioButton) rootView.findViewById(R.id.linear_layout_rb);
        mLinearLayoutRadioButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                setRecyclerViewLayoutManager(LayoutManagerType.LINEAR_LAYOUT_MANAGER);
            }
        });

        mGridLayoutRadioButton = (RadioButton) rootView.findViewById(R.id.grid_layout_rb);
        mGridLayoutRadioButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                setRecyclerViewLayoutManager(LayoutManagerType.GRID_LAYOUT_MANAGER);
            }
        });

        return rootView;
    }

    /**
     * Set RecyclerView‘s LayoutManager to the one given.
     *
     * @param layoutManagerType Type of layout manager to switch to.
     */
    public void setRecyclerViewLayoutManager(LayoutManagerType layoutManagerType) {
        int scrollPosition = 0;

        // If a layout manager has already been set, get current scroll position.
        // 如果布局管理器已经被设置，那么得到当前滚动的位置
        if (mRecyclerView.getLayoutManager() != null) {
            //得到adapter一个完全可见的View的位置
            //注意边界检查只在当前方向上执行，这以为着如果LayoutManager如果水平的，这只检查View的左右边界
            scrollPosition = ((LinearLayoutManager) mRecyclerView.getLayoutManager())
                    .findFirstCompletelyVisibleItemPosition();
        }

        switch (layoutManagerType) {
            case GRID_LAYOUT_MANAGER:
                //创建一个垂直的GridLayoutManager，SPAN_COUNT为指定的列数
                mLayoutManager = new GridLayoutManager(getActivity(), SPAN_COUNT);
                mCurrentLayoutManagerType = LayoutManagerType.GRID_LAYOUT_MANAGER;
                break;
            case LINEAR_LAYOUT_MANAGER:
                //创建一个垂直的LinearLayoutManager
                mLayoutManager = new LinearLayoutManager(getActivity());
                mCurrentLayoutManagerType = LayoutManagerType.LINEAR_LAYOUT_MANAGER;
                break;
            default:
                mLayoutManager = new LinearLayoutManager(getActivity());
                mCurrentLayoutManagerType = LayoutManagerType.LINEAR_LAYOUT_MANAGER;
        }
        //设置布局管理器
        mRecyclerView.setLayoutManager(mLayoutManager);
        //滚动到某一位置，RecyclerView没有实现滚动逻辑，而是去调用RecyclerView.LayoutManager#scrollToPosition(int)方法
        mRecyclerView.scrollToPosition(scrollPosition);
    }

    @Override
    public void onSaveInstanceState(Bundle savedInstanceState) {
        // Save currently selected layout manager.
        savedInstanceState.putSerializable(KEY_LAYOUT_MANAGER, mCurrentLayoutManagerType);
        super.onSaveInstanceState(savedInstanceState);
    }

    /**
     * Generates Strings for RecyclerView‘s adapter. This data would usually come
     * from a local content provider or remote server.
     * 为RecyclerView‘s adapter产生字符串，这些数据通常来自本地或者远程服务器
     */
    private void initDataset() {
        mDataset = new String[DATASET_COUNT];
        for (int i = 0; i < DATASET_COUNT; i++) {
            mDataset[i] = "This is element #" + i;
        }
    }
}

/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*      http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

package com.example.android.recyclerview;

import com.example.android.common.logger.Log;

import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

/**
 * Provide views to RecyclerView with data from mDataSet.
 * 使用数据集合为RecyclerView提供views
 */
public class CustomAdapter extends RecyclerView.Adapter<CustomAdapter.ViewHolder> {
    private static final String TAG = "CustomAdapter";

    private String[] mDataSet;

    // BEGIN_INCLUDE(recyclerViewSampleViewHolder)
    /**
     * Provide a reference to the type of views that you are using (custom ViewHolder)
     * 提供一个views的类型参考
     */
    public static class ViewHolder extends RecyclerView.ViewHolder {
        private final TextView textView;

        public ViewHolder(View v) {
            super(v);
            // Define click listener for the ViewHolder‘s View.为ViewHolder定义的点击监听
            v.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Log.d(TAG, "Element " + getPosition() + " clicked.");
                }
            });
            textView = (TextView) v.findViewById(R.id.textView);
        }

        public TextView getTextView() {
            return textView;
        }
    }
    // END_INCLUDE(recyclerViewSampleViewHolder)

    /**
     * Initialize the dataset of the Adapter.
     *
     * @param dataSet String[] containing the data to populate views to be used by RecyclerView.
     */
    public CustomAdapter(String[] dataSet) {
        mDataSet = dataSet;
    }

    // BEGIN_INCLUDE(recyclerViewOnCreateViewHolder)
    // Create new views (invoked by the layout manager)
    // 创建新的views（通过布局管理器调用）
    @Override
    public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
        // Create a new view.
        View v = LayoutInflater.from(viewGroup.getContext())
                .inflate(R.layout.text_row_item, viewGroup, false);

        return new ViewHolder(v);
    }
    // END_INCLUDE(recyclerViewOnCreateViewHolder)

    // BEGIN_INCLUDE(recyclerViewOnBindViewHolder)
    // Replace the contents of a view (invoked by the layout manager)
    // 替换一个view的内容
    @Override
    public void onBindViewHolder(ViewHolder viewHolder, final int position) {
        Log.d(TAG, "Element " + position + " set.");

        // Get element from your dataset at this position and replace the contents of the view
        // with that element
        // 从你的数据集中得到position元素，使用该元素替换view的内容
        viewHolder.getTextView().setText(mDataSet[position]);
    }
    // END_INCLUDE(recyclerViewOnBindViewHolder)

    // Return the size of your dataset (invoked by the layout manager)
    // 返回数据集的大小
    @Override
    public int getItemCount() {
        return mDataSet.length;
    }
}

googles示例RecyclerView

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原文地址：http://blog.csdn.net/u010121444/article/details/51354408