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Android怎么自定义ViewGroup多行多列效果

发表于:2022-11-27 作者:安全数据网编辑
编辑最后更新 2022年11月27日,这篇文章主要介绍"Android怎么自定义ViewGroup多行多列效果",在日常操作中,相信很多人在Android怎么自定义ViewGroup多行多列效果问题上存在疑惑,小编查阅了各式资料,整理出简

这篇文章主要介绍"Android怎么自定义ViewGroup多行多列效果",在日常操作中,相信很多人在Android怎么自定义ViewGroup多行多列效果问题上存在疑惑,小编查阅了各式资料,整理出简单好用的操作方法,希望对大家解答"Android怎么自定义ViewGroup多行多列效果"的疑惑有所帮助!接下来,请跟着小编一起来学习吧!

先看下效果图

每行两个子孩子

每行一个子孩子

实现思路

自定义viewGroup,实现测量和布局,使控件适应业务场景。

测量

根据父控件的宽度,平均分给每个子孩子固定的宽度。高度就是行数乘以一个子孩子的高度,再加上空隙的高度。

根据子孩子个数计算行数

val rows = if (childCount % perLineChild == 0) {            childCount / perLineChild        } else {            childCount / perLineChild + 1        }

代码示例

override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {        val width = MeasureSpec.getSize(widthMeasureSpec)        for (i in 0 until childCount) {            val child: View = getChildAt(i)            if (child.visibility != GONE) {                val lp = child.layoutParams                val childWidthMeasureSpec = getChildMeasureSpec(                    widthMeasureSpec,                    0, (width - (perLineChild - 1) * space) / perLineChild                )                val childHeightMeasureSpec = getChildMeasureSpec(                    heightMeasureSpec,                    0, lp.height                )                child.measure(childWidthMeasureSpec, childHeightMeasureSpec)            }        }        val rows = if (childCount % perLineChild == 0) {            childCount / perLineChild        } else {            childCount / perLineChild + 1        }        if (childCount > 0) {            setMeasuredDimension(                width,                getChildAt(0).measuredHeight * rows + (rows - 1) * space            )        }    }

布局

需要注意摆放的顺序和位置,每行摆放固定的个数,达到个数之后换行继续摆放

代码示例

override fun onLayout(changed: Boolean, l: Int, t: Int, r: Int, b: Int) {        var left = l        var top = t        children.forEachIndexed { index, view ->            if (index % perLineChild == 0) {                left = 0                if (index != 0) {                    top += view.measuredHeight                    top+=space                }                view.layout(left, top, view.measuredWidth + left, top + view.measuredHeight)            } else {                view.layout(left, top, view.measuredWidth + left, top + view.measuredHeight)            }            left += view.measuredWidth            left += space        }    }

完整代码

class MultiLineViewG @JvmOverloads constructor(    context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0) : ViewGroup(context, attrs, defStyleAttr) {    var perLineChild = 2    /**     * 子孩子之间的空隙     */    var space = 10    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {        val width = MeasureSpec.getSize(widthMeasureSpec)        for (i in 0 until childCount) {            val child: View = getChildAt(i)            if (child.visibility != GONE) {                val lp = child.layoutParams                val childWidthMeasureSpec = getChildMeasureSpec(                    widthMeasureSpec,                    0, (width - (perLineChild - 1) * space) / perLineChild                )                val childHeightMeasureSpec = getChildMeasureSpec(                    heightMeasureSpec,                    0, lp.height                )                child.measure(childWidthMeasureSpec, childHeightMeasureSpec)            }        }        val rows = if (childCount % perLineChild == 0) {            childCount / perLineChild        } else {            childCount / perLineChild + 1        }        if (childCount > 0) {            setMeasuredDimension(                width,                getChildAt(0).measuredHeight * rows + (rows - 1) * space            )        }    }    override fun onLayout(changed: Boolean, l: Int, t: Int, r: Int, b: Int) {        var left = l        var top = t        children.forEachIndexed { index, view ->            if (index % perLineChild == 0) {                left = 0                if (index != 0) {                    top += view.measuredHeight                    top+=space                }                view.layout(left, top, view.measuredWidth + left, top + view.measuredHeight)            } else {                view.layout(left, top, view.measuredWidth + left, top + view.measuredHeight)            }            left += view.measuredWidth            left += space        }    }}

到此,关于"Android怎么自定义ViewGroup多行多列效果"的学习就结束了,希望能够解决大家的疑惑。理论与实践的搭配能更好的帮助大家学习,快去试试吧!若想继续学习更多相关知识,请继续关注网站,小编会继续努力为大家带来更多实用的文章!

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