安卓开发之recycleView间隔线（listview形式）

最新推荐文章于 2025-12-31 19:19:25 发布

转载最新推荐文章于 2025-12-31 19:19:25 发布 · 556 阅读

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本文介绍了一个自定义的RecyclerView.ItemDecoration类——DividerLineraItemDecoration，用于在Android应用中为RecyclerView添加分割线。该类支持水平和垂直方向的列表，并允许开发者自定义分割线的样式。

“`
package com.pictureselectlist.android.view;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;

import com.pictureselectlist.android.R;

/**
* 创建人：王亮
* 创建时间：2016/12/21
* 功能作用：用于recycleview的分割线的绘制，可以使用默认视图样式，也可以使用传入的样式
*/

public class DividerLineraItemDecoration extends RecyclerView.ItemDecoration{

public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;

public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;

private View ItemDecorationView;//间隔视图
private Drawable ItemDecorationViewDrawble;//间隔视图的drawble

private int ItemDecorationViewWidth = 0;//间隔视图的宽度
private int ItemDecorationViewHeight = 0;//间隔视图的高度

private int mOrientation;

public DividerLineraItemDecoration(Context context, int orientation, View ItemDecorationView) {

    //判断传入的view以及传入的view的params是否为空，若其中一个为空则使用默认样式
    if(ItemDecorationView == null || ItemDecorationView.getLayoutParams() == null){
        ItemDecorationView = new ImageView(context);
        ItemDecorationView.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,1));
        ItemDecorationView.setBackgroundColor(context.getResources().getColor(R.color.default_line_bg));
    }

    this.ItemDecorationView = ItemDecorationView;
    this.ItemDecorationView.measure(0,0);
    this.ItemDecorationViewDrawble = ItemDecorationView.getBackground();

    if(this.ItemDecorationView.getMeasuredHeight() >= 0){
        ItemDecorationViewHeight = this.ItemDecorationView.getMeasuredHeight();
    }
    if(this.ItemDecorationView.getMeasuredWidth() >= 0){
        ItemDecorationViewWidth = this.ItemDecorationView.getMeasuredWidth();
    }
    if(ItemDecorationView.getLayoutParams().height >= 0){
        ItemDecorationViewHeight = ItemDecorationView.getLayoutParams().height;
    }
    if(ItemDecorationView.getLayoutParams().width >= 0){
        ItemDecorationViewWidth = ItemDecorationView.getLayoutParams().width;
    }


    setOrientation(orientation);
}

public void setOrientation(int orientation) {
    if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST) {
        throw new IllegalArgumentException("invalid orientation");
    }
    mOrientation = orientation;
}

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

    if (mOrientation == VERTICAL_LIST) {
        drawVertical(c, parent);
    } else {
        drawHorizontal(c, parent);
    }

}


public void drawVertical(Canvas c, RecyclerView parent) {
    final int left = parent.getPaddingLeft();
    final int right = parent.getWidth() - parent.getPaddingRight() + ItemDecorationViewWidth;

    final int childCount = parent.getChildCount();
    if(childCount > 0) {
        for (int i = 0; i < childCount - 1; i++) {
            final View child = parent.getChildAt(i);
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
                    .getLayoutParams();
            final int top = child.getBottom() + params.bottomMargin;
            final int bottom = top + ItemDecorationViewHeight;
            ItemDecorationViewDrawble.setBounds(left, top, right, bottom);
            ItemDecorationViewDrawble.draw(c);//在drable上绘制itemview

        }
    }
}

public void drawHorizontal(Canvas c, RecyclerView parent) {
    final int top = parent.getPaddingTop();
    final int bottom = parent.getHeight() - parent.getPaddingBottom();

    final int childCount = parent.getChildCount();
    if(childCount > 0) {
        for (int i = 0; i < childCount - 1; i++) {
            final View child = parent.getChildAt(i);
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
                    .getLayoutParams();
            final int left = child.getRight() + params.rightMargin;
            final int right = left + ItemDecorationViewHeight;
            ItemDecorationViewDrawble.setBounds(left, top, right, bottom);
            ItemDecorationViewDrawble.draw(c);//在drable上绘制itemview
        }
    }
}

@Override
public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent) {
    //设置itemview的偏移量
    if (mOrientation == VERTICAL_LIST) {
        outRect.set(0, 0, 0, ItemDecorationViewHeight);
    } else {
        outRect.set(0, 0, ItemDecorationViewWidth, 0);
    }
}

}“`