RecyclerView 分割线

RecyclerView 分割线 （1）

package utils;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.v4.content.ContextCompat;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;


public class RecyclerViewDivider extends RecyclerView.ItemDecoration {
    private Paint mPaint;
    private Drawable mDivider;     // 自定义的drawable
    private int mDividerHeight = 1;//分割线高度，默认为1px
    private int mOrientation;      //列表的方向：LinearLayoutManager.VERTICAL 或 LinearLayoutManager.HORIZONTAL
    private static final int[] ATTRS = new int[]{android.R.attr.listDivider};

    /**
     * @param context
     * @param orientation 列表方向
     */
    public RecyclerViewDivider(Context context, int orientation) {
        if (orientation != LinearLayoutManager.VERTICAL && orientation != LinearLayoutManager.HORIZONTAL) {
            throw new IllegalArgumentException("请输入正确的参数！");
        }
        mOrientation = orientation;
        final TypedArray a = context.obtainStyledAttributes(ATTRS);
        mDivider = a.getDrawable(0);
        a.recycle();
    }

    /**
     * 自定义分割线
     *
     * @param context
     * @param orientation 列表方向
     * @param drawableId  分割线图片
     */
    public RecyclerViewDivider(Context context, int orientation, int drawableId) {
        this(context, orientation);
        mDivider = ContextCompat.getDrawable(context, drawableId);
        mDividerHeight = mDivider.getIntrinsicHeight();
    }

    /**
     * 自定义分割线
     *
     * @param context
     * @param orientation   列表方向
     * @param dividerHeight 分割线高度
     * @param dividerColor  分割线颜色
     */
    public RecyclerViewDivider(Context context, int orientation, int dividerHeight, int dividerColor) {
        this(context, orientation);
        mDividerHeight = dividerHeight;
        mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mPaint.setColor(dividerColor);
        mPaint.setStyle(Paint.Style.FILL);
    }


    //由于Divider也有长宽高，每一个Item需要向下或者向右偏移
    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        //super.getItemOffsets(outRect, view, parent, state);
        //outRect.set(0, 0, 0, mDividerHeight);

	if(mOrientation == LinearLayoutManager.VERTICAL){
            //画横线，就是往下偏移一个分割线的高度
            outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
        }else {
            //画竖线，就是往右偏移一个分割线的宽度
            outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
        }
    }

    //绘制分割线
    @Override
    public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
        super.onDraw(c, parent, state);
        if (mOrientation == LinearLayoutManager.HORIZONTAL) {
            drawVertical(c, parent);
        } else {
            drawHorizontal(c, parent);
        }
    }


    // item 竖向显示，绘制横向 item 分割线
    private void drawHorizontal(Canvas canvas, RecyclerView parent) {
        
	//获取RecyclerView 的 padding
	final int left = parent.getPaddingLeft();
        final int right = parent.getMeasuredWidth() - parent.getPaddingRight();

        //或

        //使用 item 的 padding参数
        View childView = parent.getChildAt(0);
	final int childSize = childView..getPaddingLeft();
        final int right = childView.getMeasuredWidth() - childView.getPaddingRight();

        for (int i = 0; i < childSize; i++) {
            final View child = parent.getChildAt(i);

	    //获得child的布局信息（主要是获取,LayoutParams中的params.bottomMargin长度

            RecyclerView.LayoutParams layoutParams = (RecyclerView.LayoutParams) child.getLayoutParams();
            final int top = child.getBottom() + layoutParams.bottomMargin;
            final int bottom = top + mDividerHeight;
	    
            if (mDivider != null) {
                mDivider.setBounds(left, top, right, bottom);
                mDivider.draw(canvas);
            }
            if (mPaint != null) {
                canvas.drawRect(left, top, right, bottom, mPaint);
            }
        }
    }

    //绘制纵向 item 分割线
    private void drawVertical(Canvas canvas, RecyclerView parent) {
        final int top = parent.getPaddingTop();
        final int bottom = parent.getMeasuredHeight() - parent.getPaddingBottom();
        final int childSize = parent.getChildCount();
        for (int i = 0; i < childSize; i++) {
            final View child = parent.getChildAt(i);
            RecyclerView.LayoutParams layoutParams = (RecyclerView.LayoutParams) child.getLayoutParams();
            final int left = child.getRight() + layoutParams.rightMargin;
            final int right = left + mDividerHeight;
            if (mDivider != null) {
                mDivider.setBounds(left, top, right, bottom);
                mDivider.draw(canvas);
            }
            if (mPaint != null) {
                canvas.drawRect(left, top, right, bottom, mPaint);
            }
        }
    }

}


//使用系统list分割线
1. mRecyclerView.addItemDecoration(new RecyclerViewDivider(mContext, LinearLayoutManager.VERTICAL));

//使用自定义图片分割线
2. mRecyclerView.addItemDecoration(new RecyclerViewDivider(mContext, LinearLayoutManager.VERTICAL, R.drawable.divider_mileage));

//高度自定义10,设置分割线颜色
3.mRecyclerView.addItemDecoration(new RecyclerViewDivider(  mContext, LinearLayoutManager.VERTICAL, 10, ContextCompat.getColor(mContext, R.color.divide_gray_color)));

RecyclerView 分割线（2）

RecyclerView高度定制的“万能分割线”   https://blog.csdn.net/u013134391/article/details/64123337

https://github.com/YuJunKui1995/UniversalItemDecoration