header = LayoutInflater.from(SearchActivity.this).inflate(R.layout.layout_search_main, (ViewGroup) findViewById(android.R.id.content), false); //header = ViewGroup.inflate(SearchActivity.this, R.layout.layout_search_main, null);

public class DividerGridItemDecoration extends RecyclerView.ItemDecoration {

private Drawable mDivider;

public DividerGridItemDecoration(Context context)
{
    mDivider = ContextCompat.getDrawable(context, R.drawable.divider_quote_dark);
}

@Override
public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state)
{

    drawHorizontal(c, parent);
    drawVertical(c, parent);

}

private int getSpanCount(RecyclerView parent)
{
    // 列數
    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();
        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)
{
    RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
    if (layoutManager instanceof GridLayoutManager)
    {
        if ((pos + 1) % spanCount == 0)// 如果是最後一列，則不需要繪製右邊
        {
            return true;
        }
    } else if (layoutManager instanceof StaggeredGridLayoutManager)
    {
        int orientation = ((StaggeredGridLayoutManager) layoutManager)
                .getOrientation();
        if (orientation == StaggeredGridLayoutManager.VERTICAL)
        {
            if ((pos + 1) % spanCount == 0)// 如果是最後一列，則不需要繪製右邊
            {
                return true;
            }
        } else
        {
            childCount = childCount - childCount % spanCount;
            if (pos >= childCount)// 如果是最後一列，則不需要繪製右邊
                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)// 如果是最後一行，則不需要繪製底部
            return true;
    } else if (layoutManager instanceof StaggeredGridLayoutManager)
    {
        int orientation = ((StaggeredGridLayoutManager) layoutManager)
                .getOrientation();
        // StaggeredGridLayoutManager 且縱向滾動
        if (orientation == StaggeredGridLayoutManager.VERTICAL)
        {
            childCount = childCount - childCount % spanCount;
            // 如果是最後一行，則不需要繪製底部
            if (pos >= childCount)
                return true;
        } else
        // StaggeredGridLayoutManager 且橫向滾動
        {
            // 如果是最後一行，則不需要繪製底部
            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))// 如果是最後一行，則不需要繪製底部
    {
        outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
    } else if (isLastColum(parent, itemPosition, spanCount, childCount))// 如果是最後一列，則不需要繪製右邊
    {
        outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
    } else
    {
        outRect.set(0, 0, mDivider.getIntrinsicWidth(),
                mDivider.getIntrinsicHeight());
    }
}
 

}

4. 理解Android Architecture Components系列（一）

mQQPop = EasyPopup.create() .setContext(this) .setContentView(R.layout.layout_right_pop) .setAnimationStyle(R.style.RightTop2PopAnim) .setOnViewListener(new EasyPopup.OnViewListener() { @Override public void initViews(View view, EasyPopup basePopup) { View arrowView = view.findViewById(R.id.v_arrow); arrowView.setBackground(new TriangleDrawable(TriangleDrawable.TOP, Color.parseColor("#88FF88"))); } }) .setFocusAndOutsideEnable(true) // .setBackgroundDimEnable(true) // .setDimValue(0.5f) // .setDimColor(Color.RED) // .setDimView(mTitleBar) .apply();

<View
    android:id="@+id/v_arrow"
    android:layout_width="20dp"
    android:layout_height="10dp"
    android:layout_gravity="start"
    android:layout_marginEnd="10dp"
    android:layout_marginRight="10dp"/>

<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:background="#88FF88"
    android:divider="@drawable/divider_horizontal_bg"
    android:gravity="center_horizontal"
    android:orientation="vertical"
    android:showDividers="middle">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="30dp"
        android:layout_marginLeft="50dp"
        android:layout_marginRight="50dp"
        android:gravity="center"
        android:text="one"
        android:textSize="14sp"/>

    <TextView
        android:layout_width="match_parent"
        android:layout_height="30dp"
        android:gravity="center"
        android:text="two"
        android:textSize="14sp"/>

    <TextView
        android:layout_width="match_parent"
        android:layout_height="30dp"
        android:gravity="center"
        android:text="three"
        android:textSize="14sp"/>

    <TextView
        android:layout_width="match_parent"
        android:layout_height="30dp"
        android:gravity="center"
        android:text="four"
        android:textSize="14sp"/>

    <TextView
        android:layout_width="match_parent"
        android:layout_height="30dp"
        android:gravity="center"
        android:text="five"
        android:textSize="14sp"/>
</LinearLayout>