Android基础控件——RecyclerView实现混排效果,仿网易云音乐

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前言

最近在使用网易云音乐的时候,看到如下图的排版效果图,自己也想实现一个

这里写图片描述

这里采用网上用法最多的方式,而且是比较简单的方式实现的,想要做项目的同学也可以快速入手搞定首页界面,可以在最快的时间内模仿出来,且效果达到90%以上的相似

效果演示

至于图片的加载你们可以根据网上的Api获取相应的图片加载到对应的位置,这里只是采用本地图片来演示

这里写图片描述

实现分析

这里是采用RecyclerView的GridLayoutManager的一个SpanSize这么一个东西,从下图很容易知道其意思

这里写图片描述

项目结构

项目结构可能对初学者感觉很庞大,不用担心,这里我会按照下面的包名划分,从最简单的开始分析

这里写图片描述

引入依赖

首先是在Gradle中引入对RecyclerView的依赖

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compile 'com.android.support:recyclerview-v7:25.3.1'

View包

由于项目用到的图片是有规格限定的,所以需要对ImageView覆写,得到我们想要尺寸的图片

  • SquareImageView:正方形图片
  • RectImageView:长方形图片
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public class SquareImageView extends android.support.v7.widget.AppCompatImageView {
public SquareImageView(Context context) {
this(context,null);
}
public SquareImageView(Context context, @Nullable AttributeSet attrs) {
this(context, attrs,0);
}
public SquareImageView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
setScaleType(ScaleType.FIT_XY);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, widthMeasureSpec);
}
}
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public class RectImageView extends android.support.v7.widget.AppCompatImageView {
public RectImageView(Context context) {
this(context, null);
}
public RectImageView(Context context, @Nullable AttributeSet attrs) {
this(context, attrs, 0);
}
public RectImageView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
setScaleType(ScaleType.FIT_XY);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int widthMode = MeasureSpec.getMode(widthMeasureSpec);
int width = MeasureSpec.getSize(widthMeasureSpec);
// 设置大小为宽度的三分之二
int halfWidthMeasureSpec = MeasureSpec.makeMeasureSpec(width / 3 * 2, widthMode);
super.onMeasure(widthMeasureSpec, halfWidthMeasureSpec);
}
}

Music包

这里是我们存储实体的地方,其中四种类型的划分,分别对应项目展示中的前三个模块的划分,其中还有一个标题也算是一种类型,所以共四种

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public class Music {
public int type;
public String title;
// 后期可加入Glide加载网络图片Url
public int imageId;
public interface TYPE {
int TYPE_GRID_THREE = 0x01;
int TYPE_GRID_TWO = 0x02;
int TYPE_LIST = 0x03;
int TYPE_TITLE = 0x04;
}
}

Listener包

由于RecyclerView自身是没有点击事件的,所以这个包是RecyclerView的点击事件接口

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public interface OnItemClickListener {
void OnItemClick(int position);
}

Decoration包

由于RecyclerView是不提供分割线的,所以这个包是自定义的分割线

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public class SpacesItemDecoration extends RecyclerView.ItemDecoration {
private int space;
public SpacesItemDecoration(int space) {
this.space = space;
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
outRect.left = space;
outRect.right = space;
outRect.bottom = space;
outRect.top = space;
}
}

ViewHolder

这里存储的是我们混排效果的控件,标题可能会有点区别,其他是一样的效果,为了后期方便拓展,我们就把他们分开,不代码复用

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public class GridThreeViewHolder extends RecyclerView.ViewHolder {
public SquareImageView iv_icon;
public TextView tv_content;
public GridThreeViewHolder(View itemView) {
super(itemView);
iv_icon = (SquareImageView) itemView.findViewById(R.id.iv_icon);
tv_content = (TextView) itemView.findViewById(R.id.tv_content);
}
}
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public class GridTwoViewHolder extends RecyclerView.ViewHolder {
public RectImageView iv_icon;
public TextView tv_content;
public GridTwoViewHolder(View itemView) {
super(itemView);
iv_icon = (RectImageView) itemView.findViewById(R.id.iv_icon);
tv_content = (TextView) itemView.findViewById(R.id.tv_content);
}
}
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public class ListViewHolder extends RecyclerView.ViewHolder {
public RectImageView iv_icon;
public TextView tv_content;
public ListViewHolder(View itemView) {
super(itemView);
iv_icon = (RectImageView) itemView.findViewById(R.id.iv_icon);
tv_content = (TextView) itemView.findViewById(R.id.tv_content);
}
}
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public class TitleViewHolder extends RecyclerView.ViewHolder {
public TextView tv_content;
public TitleViewHolder(View itemView) {
super(itemView);
tv_content = (TextView) itemView.findViewById(R.id.tv_content);
}
}

Adapter包

这里就是对所有ViewHolder的控制器,然而这里并不是混排效果实现的最终地方,只不过是填充数据的地方

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public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> implements View.OnClickListener {
private List<Music> mList;
private Context mContext;
private LayoutInflater mInflater;
/**
* 点击事件
*/
private OnItemClickListener mOnItemClickListener;
public void setOnItemClickListener(OnItemClickListener onItemClickListener) {
this.mOnItemClickListener = onItemClickListener;
}
public RecyclerAdapter(Context context, List<Music> list) {
this.mList = list;
this.mContext = context;
this.mInflater = LayoutInflater.from(context);
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view;
RecyclerView.ViewHolder mViewHolder = null;
if (viewType == Music.TYPE.TYPE_GRID_THREE) {
view = mInflater.inflate(R.layout.item_grid_three, parent, false);
mViewHolder = new GridThreeViewHolder(view);
} else if (viewType == Music.TYPE.TYPE_GRID_TWO) {
view = mInflater.inflate(R.layout.item_grid_two, parent, false);
mViewHolder = new GridTwoViewHolder(view);
} else if (viewType == Music.TYPE.TYPE_LIST) {
view = mInflater.inflate(R.layout.item_list, parent, false);
mViewHolder = new ListViewHolder(view);
} else if (viewType == Music.TYPE.TYPE_TITLE) {
view = mInflater.inflate(R.layout.item_title, parent, false);
mViewHolder = new TitleViewHolder(view);
}
return mViewHolder;
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
switch (getItemViewType(position)) {
case Music.TYPE.TYPE_GRID_THREE:
GridThreeViewHolder gHolder_three = (GridThreeViewHolder) holder;
gHolder_three.tv_content.setText(mList.get(position).title);
gHolder_three.iv_icon.setImageResource(mList.get(position).imageId);
//点击事件
gHolder_three.itemView.setOnClickListener(this);
gHolder_three.itemView.setTag(position);
break;
case Music.TYPE.TYPE_GRID_TWO:
GridTwoViewHolder gHolder_two = (GridTwoViewHolder) holder;
gHolder_two.tv_content.setText(mList.get(position).title);
gHolder_two.iv_icon.setImageResource(mList.get(position).imageId);
//点击事件
gHolder_two.itemView.setOnClickListener(this);
gHolder_two.itemView.setTag(position);
break;
case Music.TYPE.TYPE_LIST:
ListViewHolder lHolder = (ListViewHolder) holder;
lHolder.tv_content.setText(mList.get(position).title);
lHolder.iv_icon.setImageResource(mList.get(position).imageId);
//点击事件
lHolder.itemView.setOnClickListener(this);
lHolder.itemView.setTag(position);
break;
case Music.TYPE.TYPE_TITLE:
TitleViewHolder tHolder = (TitleViewHolder) holder;
tHolder.tv_content.setText(mList.get(position).title);
//点击事件
tHolder.itemView.setOnClickListener(this);
tHolder.itemView.setTag(position);
break;
}
}
@Override
public int getItemViewType(int position) {
return mList.get(position).type;
}
@Override
public int getItemCount() {
return mList.size();
}
@Override
public void onClick(View v) {
if (mOnItemClickListener != null) {
int position = (int) v.getTag();
mOnItemClickListener.OnItemClick(position);
}
}
}

Activity

这里就是我们实现混排效果的关键,我们会根据不同类型的数据,对RecyclerView的SpanSize的进行设置

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public class MainActivity extends AppCompatActivity implements OnItemClickListener {
private RecyclerView ry;
private GridLayoutManager layoutManager;
private RecyclerAdapter mAdapter;
private static List<Music> mList;
/**
* 模拟本地数据
*/
static {
mList = new ArrayList<>();
for (int i = 0; i < 1; i++) {
Music music = new Music();
music.type = Music.TYPE.TYPE_TITLE;
music.imageId = R.drawable.ic_cover;
music.title = "推荐歌单";
mList.add(music);
}
for (int i = 0; i < 6; i++) {
Music music = new Music();
music.type = Music.TYPE.TYPE_GRID_THREE;
music.imageId = R.drawable.ic_cover;
music.title = "先不要降温!我没钱买衣服";
mList.add(music);
}
for (int i = 0; i < 1; i++) {
Music music = new Music();
music.type = Music.TYPE.TYPE_TITLE;
music.imageId = R.drawable.ic_cover;
music.title = "推荐MV";
mList.add(music);
}
for (int i = 0; i < 4; i++) {
Music music = new Music();
music.type = Music.TYPE.TYPE_GRID_TWO;
music.imageId = R.drawable.ic_cover;
music.title = "Perfect Day";
mList.add(music);
}
for (int i = 0; i < 1; i++) {
Music music = new Music();
music.type = Music.TYPE.TYPE_TITLE;
music.imageId = R.drawable.ic_cover;
music.title = "精选专栏";
mList.add(music);
}
for (int i = 0; i < 3; i++) {
Music music = new Music();
music.type = Music.TYPE.TYPE_LIST;
music.imageId = R.drawable.ic_cover;
music.title = "去看《银翼杀手2049》前,你应该知道的三件事";
mList.add(music);
}
for (int i = 0; i < 1; i++) {
Music music = new Music();
music.type = Music.TYPE.TYPE_TITLE;
music.imageId = R.drawable.ic_cover;
music.title = "最新音乐";
mList.add(music);
}
for (int i = 0; i < 6; i++) {
Music music = new Music();
music.type = Music.TYPE.TYPE_GRID_THREE;
music.imageId = R.drawable.ic_cover;
music.title = "[BGM]一定听过的神级背景配乐";
mList.add(music);
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ry = (RecyclerView) findViewById(R.id.ry);
layoutManager = new GridLayoutManager(this, 6);
layoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
@Override
public int getSpanSize(int position) {
int type = mList.get(position).type;
if (type == Music.TYPE.TYPE_GRID_THREE) {
return 2;
} else if (type == Music.TYPE.TYPE_GRID_TWO) {
return 3;
} else if (type == Music.TYPE.TYPE_LIST) {
return 6;
} else if (type == Music.TYPE.TYPE_TITLE) {
return 6;
}
return 0;
}
});
ry.setLayoutManager(layoutManager);
ry.addItemDecoration(new SpacesItemDecoration(2));
// 填充数据
mAdapter = new RecyclerAdapter(this, mList);
mAdapter.setOnItemClickListener(this);
ry.setAdapter(mAdapter);
}
@Override
public void OnItemClick(int position) {
String title = mList.get(position).title;
Toast.makeText(this, title, Toast.LENGTH_SHORT).show();
}
}

layout布局文件

这里的布局很简单,比如用到我们的正方形图片,长方形图片等,这里就不做代码贴出,详细可以查看源码

源码下载

源码下载

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