RecyclerViewItemDivider.java 1.65 KB
package com.cnlive.goldenline.util;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.view.View;

/**
 * RecyclerViewItem的分割线
 * Created by zhangshuai on 2016-04-18.
 */
public class RecyclerViewItemDivider extends RecyclerView.ItemDecoration {

    private Drawable mDrawable;

    public RecyclerViewItemDivider(@NonNull Context context, int resId) {
        //在这里我传入作为Divider的Drawable对象
        mDrawable=context.getResources().getDrawable(resId);
    }

    @Override
    public void onDrawOver(@NonNull Canvas c, @NonNull RecyclerView parent) {
        //super.onDrawOver(c, parent);
        final int left=parent.getPaddingLeft();
        final int right=parent.getWidth()- parent.getPaddingRight();
        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();
            //以下计算主要用来确定绘制的位置
            final int top = child.getBottom() + params.bottomMargin;
            final int bottom = top + mDrawable.getIntrinsicHeight();
            mDrawable.setBounds(left, top, right, bottom);
            mDrawable.draw(c);
        }
    }

    @Override
    public void getItemOffsets(@NonNull Rect outRect, int position, RecyclerView parent) {
        outRect.set(0, 0, 0, mDrawable.getIntrinsicWidth());
    }
}