Android5.x之RecyclerView使用(5)网格布局
众所周知RecyclerView有所谓三种布局管理器
1：LinearLayoutManager线性布局管理器
2：GridLayoutManager网格布局管理器
3：StaggeredGridLayoutManager瀑布流布局管理器
用于取代ListView 和rGridView,本文讲述如何使用GridLayoutManager实现一个方形带分割线的网格布局
分割线代码
/** * 在鸿洋写的该类的基础上进行了修改(达到自己要的效果:四周都有分割线) * * @author zhy */
public class DividerGridItemDecoration extends RecyclerView.ItemDecoration {
private static final int[] ATTRS = new int[]{android.R.attr.listDivider};
private Drawable mDivider;
/** * 显示的列数 */
private int column_num;
public DividerGridItemDecoration(Context context, int num) {
final TypedArray a = context.obtainStyledAttributes(ATTRS);
mDivider = a.getDrawable(0);
a.recycle();
column_num = num;
}
@Override
public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
drawHorizontal(c, parent);
drawVertical(c, parent);
}
private int getSpanCount(RecyclerView parent) {
// 列数
int spanCount = -1;
RecyclerView.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();
int top = 0;
int bottom = 0;
if ((i / column_num) == 0) {
//画item最上面的分割线
top = 0;
bottom = top + mDivider.getIntrinsicHeight();
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
//画item下面的分割线
top = child.getBottom() + params.bottomMargin;
bottom = top + mDivider.getIntrinsicHeight();
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
} else {
//画item下面的分割线
top = child.getBottom() + params.bottomMargin;
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;
int left = 0;
int right = 0;
if ((i % column_num) == 0) {
//item左边分割线
left = 0;
right = left + mDivider.getIntrinsicWidth();
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
//item右边分割线
left = child.getRight() + params.rightMargin;
right = left + mDivider.getIntrinsicWidth();
} else {
left = child.getRight() + params.rightMargin;
right = left + mDivider.getIntrinsicWidth();
}
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
}
}
private boolean isLastColum(RecyclerView parent, int pos, int spanCount,
int childCount) {
RecyclerView.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) {
RecyclerView.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;
}
@SuppressWarnings("deprecation")
@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());
}
}自定义RelativeLayout,长宽相等
/**使高度和宽度一致 * Created by xuenan on 2016/7/8. */
public class SquareRelativeLayout extends RelativeLayout{
public SquareRelativeLayout(Context context, AttributeSet attrs,
int defStyle) {
super(context, attrs, defStyle);
}
public SquareRelativeLayout(Context context, AttributeSet attrs) {
super(context, attrs);
}
public SquareRelativeLayout(Context context) {
super(context);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
setMeasuredDimension(getDefaultSize(0, widthMeasureSpec),
getDefaultSize(0, heightMeasureSpec));
int childWidthSize = getMeasuredWidth();
// 高度和宽度一样
heightMeasureSpec = widthMeasureSpec = MeasureSpec.makeMeasureSpec(
childWidthSize, MeasureSpec.EXACTLY);
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}还有Activity和Adapter
public class MainActivity extends AppCompatActivity {
private RecyclerView mRecyclerView;
private RecyclerViewGridAdapter mAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findView();
initValue();
}
private void findView() {
mRecyclerView = (RecyclerView) findViewById(R.id.activity_station_detail_rv);
}
private void initValue() {
List<String> mDatas = new ArrayList<>();
mDatas.add("全景");
mDatas.add("前台");
mDatas.add("大厅");
mDatas.add("后台");
mDatas.add("大厅");
mDatas.add("全景");
mDatas.add("前台");
mDatas.add("后台");
mDatas.add("全景");
mDatas.add("后台");
mDatas.add("大厅");
mAdapter = new RecyclerViewGridAdapter(this, mDatas);
GridLayoutManager layoutManager = new GridLayoutManager(this, 4);
mRecyclerView.setLayoutManager(layoutManager);
mRecyclerView.addItemDecoration(new DividerGridItemDecoration(this, 4));
mRecyclerView.setAdapter(mAdapter);
}
}//必须要有Viewhoder泛型
public class RecyclerViewGridAdapter extends RecyclerView.Adapter <RecyclerViewGridAdapter.MyViewHolder> {
private LayoutInflater mInflater;
private List<String> mDatas;
public RecyclerViewGridAdapter(Context mContext, List<String> objects) {
mInflater = LayoutInflater.from(mContext);
mDatas = objects;
}
//布局填充
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = mInflater.inflate(R.layout.item_station_detail_videolist, parent, false);
MyViewHolder viewHolder = new MyViewHolder(view);
return viewHolder;
}
//数据设置
@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
holder.textView.setText(mDatas.get(position));
}
//返回数据的数量
@Override
public int getItemCount() {
return mDatas.size();
}
class MyViewHolder extends RecyclerView.ViewHolder {
public TextView textView;
public MyViewHolder(View itemView) {
super(itemView);
textView = (TextView) itemView.findViewById(
R.id.item_station_detail_video_tv);
}
}
}两个布局文件
主Activity
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:orientation="vertical" tools:context="com.longlian.recyclerviewgrid.MainActivity">
<RelativeLayout android:layout_width="match_parent" android:layout_height="40dp" android:paddingLeft="8dp" android:paddingRight="8dp">
<TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="视频选择" android:layout_centerVertical="true" android:textSize="@dimen/large_text_size" android:textColor="@color/text_black"/>
</RelativeLayout>
<android.support.v7.widget.RecyclerView android:id="@+id/activity_station_detail_rv" android:layout_width="match_parent" android:layout_height="wrap_content"/>
</LinearLayout>item
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent" android:gravity="center">
<com.longlian.recyclerviewgrid.SquareRelativeLayout android:layout_width="match_parent" android:layout_height="match_parent">
<TextView android:id="@+id/item_station_detail_video_tv" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerInParent="true" android:textSize="@dimen/large_text_size" android:textColor="@color/text_black"/>
</com.longlian.recyclerviewgrid.SquareRelativeLayout>
</LinearLayout>分割线中图片资源的引用
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">@color/colorPrimary</item>
<item name="colorPrimaryDark">@color/colorPrimaryDark</item>
<item name="colorAccent">@color/colorAccent</item>
<item name="android:listDivider">@drawable/divider_bg</item>
</style>THIS ALL…