我們寫一個(gè)類繼承自AppCompatTextView，通過onMeasure方法得到控件的寬高，通過Paint的getTextBounds（）也可以知道文字的寬高，我們看到有5個(gè)節(jié)點(diǎn)需要處理，我們把屏幕劃分成5個(gè)等份，每個(gè)等份都相等，這里用itemWidth 表示每個(gè)相同的等份。文字居中的寫法很簡(jiǎn)單，

itemWidth / 2 - textWidth / 2

代碼

package cn.wwj.customview.widget
import android.content.Context
import android.graphics.Canvas
import android.graphics.Color
import android.graphics.Paint
import android.graphics.Rect
import android.text.TextPaint
import android.util.AttributeSet
import android.util.Log
import androidx.annotation.Nullable
import androidx.appcompat.widget.AppCompatTextView
import androidx.core.content.ContextCompat
import androidx.core.view.marginTop
import cn.wwj.customview.R
import cn.wwj.customview.dp2px
import cn.wwj.customview.sp2px
/**
 * 節(jié)點(diǎn)進(jìn)度條
 */
class NodePointProcessBar : AppCompatTextView {
    /**
     * 文字畫筆
     */
    private lateinit var mTextPaint: TextPaint
    /**
     * 圓畫筆
     */
    private lateinit var mCirclePaint: Paint
    private var isDebug = false
    /**
     * 已完成文字顏色
     */
    private var mCompleteTextColor: Int = ContextCompat.getColor(context, android.R.color.black)
    /**
     * 處理中文字顏色
     */
    private var mProcessTextColor: Int = ContextCompat.getColor(context, R.color.purple)
    /**
     * 待處理的文字顏色
     */
    private var mWaitProcessTextColor: Int = ContextCompat.getColor(context, R.color.gray_text)
    /**
     * 繪制的節(jié)點(diǎn)個(gè)數(shù)，由底部節(jié)點(diǎn)標(biāo)題數(shù)量控制
     */
    private var mCircleCount = 0
    private var TAG = "NodePointProcessBar"
    /**
     * 圓的半徑
     */
    private var mCircleRadius = 5f.dp2px()
    /**
     * 圓圈的邊框線
     */
    private var mCircleBorder = 1f.dp2px()
    /**
     * 線的寬度
     */
    private var mLineWidth = 1f.dp2px()
    /**
     * 線之間的左右邊距
     */
    private var mLineMargin = 4f.dp2px()
    /**
     * 文字和圓圈之間的距離
     */
    var mTextCircleMargin = 7f.dp2px()
    /**
     * 文字的水平邊距
     */
    private var mTextLeftRightMargin = 8f.dp2px()
    /**
     * 計(jì)算內(nèi)容的高度 和 寬度
     */
    private var mContentHeight = 0f
    private var mContentWidth = 0f
    /**
     * 節(jié)點(diǎn)底部的文字列表
     */
    private var mTextList: List<String> = mutableListOf()
    /**
     * 選中項(xiàng)集合
     */
    private var mProcessIndexSet: Set<Int> = mutableSetOf()
    /**
     * 文字同寬高的矩形，用來測(cè)量文字
     */
    private var mTextBoundList: MutableList<Rect> = mutableListOf()
    /**
     * 計(jì)算文字寬高的矩形
     */
    private val mRect = Rect()
    constructor(context: Context) : this(context, null)
    constructor(context: Context, @Nullable attrs: AttributeSet?) : this(context, attrs, 0)
    constructor(
        context: Context,
        @Nullable attrs: AttributeSet?,
        defStyleAttr: Int
    ) : super(context, attrs, defStyleAttr) {
        val appearance = context.obtainStyledAttributes(attrs, R.styleable.NodePointProcessBar)
        mCompleteTextColor = appearance.getColor(
            R.styleable.NodePointProcessBar_completedTextColor, mCompleteTextColor
        )
        mWaitProcessTextColor = appearance.getColor(
            R.styleable.NodePointProcessBar_processTextColor, mWaitProcessTextColor
        )
        mProcessTextColor =
            appearance.getColor(
                R.styleable.NodePointProcessBar_waitProcessTextColor,
                mProcessTextColor
            )
        isDebug = appearance.getBoolean(
            R.styleable.NodePointProcessBar_isDebug, isDebug
        )
        mTextCircleMargin = appearance.getDimension(
            R.styleable.NodePointProcessBar_textCircleMargin, mTextCircleMargin
        )
        mTextLeftRightMargin = appearance.getDimension(
            R.styleable.NodePointProcessBar_textLeftRightMargin, mTextLeftRightMargin
        )
        mCircleRadius = appearance.getDimension(
            R.styleable.NodePointProcessBar_npbCircleRadius, mCircleRadius
        )
        mCircleBorder = appearance.getDimension(
            R.styleable.NodePointProcessBar_circleBorder, mCircleBorder
        )
        mLineWidth = appearance.getDimension(
            R.styleable.NodePointProcessBar_lineWidth, mLineWidth
        )
        mLineMargin = appearance.getDimension(
            R.styleable.NodePointProcessBar_lineMargin, mLineMargin
        )
        initPaint()
        show(mTextList, mProcessIndexSet)
    }
    /**
     * 初始化畫筆屬性
     */
    private fun initPaint() {
        // 設(shè)置文字畫筆
        mTextPaint = TextPaint()
        mTextPaint.isAntiAlias = true
        mTextPaint.textSize = textSize
        mTextPaint.color = mWaitProcessTextColor
        // 設(shè)置圓圈畫筆
        mCirclePaint = Paint()
        mCirclePaint.isAntiAlias = true
        mCirclePaint.color = mProcessTextColor
        mCirclePaint.style = Paint.Style.STROKE
        mCirclePaint.strokeWidth = mCircleBorder
    }
    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec)
        val widthMode = MeasureSpec.getMode(widthMeasureSpec)
        val heightMode = MeasureSpec.getMode(heightMeasureSpec)
        Log.d(TAG, "---------------onMeasure()")
        measureText()
        val widthSize = if (MeasureSpec.EXACTLY == widthMode) {
            MeasureSpec.getSize(widthMeasureSpec)
        } else {
            mContentWidth.toInt()
        }
        val heightSize = if (MeasureSpec.EXACTLY == heightMode) {
            MeasureSpec.getSize(heightMeasureSpec)
        } else {
            mContentHeight.toInt()
        }
        /**
         * 設(shè)置控件的寬高
         */
        setMeasuredDimension(widthSize, heightSize)
        calcContentWidthHeight()
    }
    /**
     * 測(cè)量文字的長(zhǎng)寬，將文字視為rect矩形
     */
    private fun measureText() {
        Log.d(TAG, "---------------measureText()")
        mTextBoundList.clear()
        for (name in mTextList) {
            mRect.setEmpty()
            mTextPaint.getTextBounds(name, 0, name.length, mRect)
            mTextBoundList.add(mRect)
        }
    }
    /**
     * 獲取內(nèi)容的高度,如果控件的寬度小于內(nèi)容的寬度,意味著一行放不下了,文字的大小減小1sp,重新測(cè)量文字的寬高,重新
     */
    private fun calcContentWidthHeight() {
        // 一開始沒有傳遞文字的
        mContentHeight = if (mTextBoundList.isNotEmpty()) {
            mCircleRadius * 2 + mTextCircleMargin + mRect.height() + getBaseline(mTextPaint)
        } else {
            mTextPaint.getTextBounds("中", 0, 1, mRect)
            mCircleRadius * 2 + mTextCircleMargin + mRect.height() + getBaseline(mTextPaint)
        }
        if (measuredWidth == 0 || mTextBoundList.isEmpty()) {
            return
        }
        mContentWidth = 0f
        for (rect in mTextBoundList) {
            mContentWidth += rect.width()
        }
        Log.d(TAG, "---------------measuredWidth=$measuredWidth,mContentWidth=$mContentWidth")
        // 如果控件的寬度小于內(nèi)容的寬度加文本的邊距,意味著一行放不下了,文字的大小減小1sp,重新測(cè)量文字的寬高后,設(shè)置控件得高度
        // 如果控件的寬度大于內(nèi)容的寬度加文本的邊距,意味著一行放得下,設(shè)置控件得高度
        if (measuredWidth - mContentWidth < (mTextLeftRightMargin * (mTextList.size - 1))) {
            mTextPaint.textSize = mTextPaint.textSize - 1f.sp2px()
            measureText()
            calcContentWidthHeight()
            return
        }
        setMeasuredDimension(measuredWidth, mContentHeight.toInt())
    }
    override fun onDraw(canvas: Canvas) {
        //若未設(shè)置節(jié)點(diǎn)標(biāo)題或者選中項(xiàng)的列表，則取消繪制
        if (mTextList.isEmpty() || mTextBoundList.isEmpty()) {
            return
        }
        //畫灰色圓圈的個(gè)數(shù)
        mCircleCount = mTextList.size
        // 每一段文字的Y坐標(biāo)
        val textY = getBaseline(mTextPaint) + height / 2 + marginTop / 2
        mCirclePaint.strokeWidth = mCircleBorder
        //繪制文字和圓形
        for (i in 0 until mCircleCount) {
            if (mProcessIndexSet.contains(i)) {
                // 正在處理中
                if (mProcessIndexSet.size == i + 1) {
                    mCirclePaint.style = Paint.Style.FILL
                    // 正在處理中的文字顏色
                    mTextPaint.color = mProcessTextColor
                    mCirclePaint.color = mProcessTextColor
                } else {
                    //處理完成圓圈空心
                    mCirclePaint.style = Paint.Style.STROKE
                    //處理完成文字顏色
                    mTextPaint.color = mCompleteTextColor
                    mCirclePaint.color = mProcessTextColor
                }
            } else {
                //待處理
                mCirclePaint.color = mWaitProcessTextColor
                mCirclePaint.style = Paint.Style.FILL
                mTextPaint.color = mWaitProcessTextColor
            }
            //每一段文字寬度
            val textWidth = mTextBoundList[i].width()
            // 每一段寬度
            val itemWidth = width * 1f / mCircleCount
            // 每一段文字居中
            // |----text----|----text----|
            //    一段文字       一段文字
            //每一段文字起始的X坐標(biāo)
            val textX = itemWidth / 2f - textWidth / 2f + i * itemWidth
            canvas.drawText(mTextList[i], textX, textY, mTextPaint)
            //每一個(gè)圓圈的Y坐標(biāo)
            val circleY = height / 2f - mCircleRadius - mTextCircleMargin / 2
            //每一個(gè)圓圈的X坐標(biāo)
            val circleX = itemWidth / 2 + i * itemWidth
            canvas.drawCircle(
                circleX,
                circleY,
                mCircleRadius,
                mCirclePaint
            )
            // 畫線,兩個(gè)圓圈之間一條線段
            mCirclePaint.strokeWidth = mLineWidth
            if (i < mCircleCount - 1) {
                //已經(jīng)處理過的線顏色
                if (mProcessIndexSet.contains(i + 1)) {
                    mCirclePaint.color = mProcessTextColor
                } else {
                    // 待處理的線段顏色
                    mCirclePaint.color = mWaitProcessTextColor
                }
                // 線段起始 x 坐標(biāo)
                val lineStartX = itemWidth * i + itemWidth / 2f + mCircleRadius + mLineMargin
                // 線段結(jié)束 x 坐標(biāo)
                val lineEndX =
                    itemWidth * i + itemWidth + itemWidth / 2f - mCircleRadius - mLineMargin
                canvas.drawLine(
                    lineStartX,
                    circleY,
                    lineEndX,
                    circleY,
                    mCirclePaint
                )
            }
            Log.d("tag", "--------itemWidth=$itemWidth")
        }
        if (isDebug) {
            mCirclePaint.color = Color.RED
            canvas.drawLine(
                0f,
                height / 2f - 1f.dp2px() / 2,
                width * 1F,
                height / 2f + 1f.dp2px() / 2,
                mCirclePaint
            )
        }
    }
    /**
     * 供外部調(diào)用，展示內(nèi)容
     * @param titles 要展示的內(nèi)容列表
     * @param progressIndexSet 節(jié)點(diǎn)選中項(xiàng)集合
     */
    fun setNodeData(titles: List<String>, progressIndexSet: Set<Int>) {
        mTextList = titles
        mProcessIndexSet = progressIndexSet
        measureText()
        calcContentWidthHeight()
        invalidate()
    }
    /**
     * 獲取文字的基線
     */
    private fun getBaseline(p: Paint): Float {
        val fontMetrics: Paint.FontMetrics = p.fontMetrics
        return (fontMetrics.bottom - fontMetrics.top) - fontMetrics.descent
    }
}

這里的show()方法用于展示內(nèi)容，第一個(gè)參數(shù)要展示的內(nèi)容列表，第二個(gè)參數(shù)代表節(jié)點(diǎn)選中項(xiàng)集合，緊接著測(cè)量文字的寬高，調(diào)用這個(gè)方法calcContentWidthHeight（）獲取文字的高度，然后設(shè)置文字的寬高，代碼中的注釋寫的很詳細(xì)，我們就不再細(xì)說了

聲明下style

attrs.xml

 <declare-styleable name="NodePointProcessBar">
        <attr name="completedTextColor" format="color" />
        <attr name="processTextColor" format="color" />
        <attr name="waitProcessTextColor" format="color" />
        <attr name="textCircleMargin" format="dimension" />
        <attr name="textLeftRightMargin" format="dimension" />
        <attr name="npbCircleRadius" format="dimension" />
        <attr name="circleBorder" format="dimension" />
        <attr name="lineWidth" format="dimension" />
        <attr name="lineMargin" format="dimension" />
        <attr name="isDebug" format="boolean" />
    </declare-styleable>

新建一個(gè)ExtendUtil.kt文件

fun Int.sp2px(): Int {
    val displayMetrics = Resources.getSystem().displayMetrics
    return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, this.toFloat(), displayMetrics)
        .toInt()
}
fun Float.sp2px(): Float {
    val displayMetrics = Resources.getSystem().displayMetrics
    return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, this, displayMetrics)
}
fun Int.dp2px(): Int {
    val displayMetrics = Resources.getSystem().displayMetrics
    return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, this.toFloat(), displayMetrics)
        .toInt()
}
fun Float.dp2px(): Float {
    val displayMetrics = Resources.getSystem().displayMetrics
    return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, this, displayMetrics)
}

接著創(chuàng)建布局文件

activity_node_progress_bar.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <cn.wwj.customview.widget.NodePointProcessBar
        android:id="@+id/nodePointPb"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:textSize="18sp"
        android:layout_marginHorizontal="10dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:isDebug="false"
        app:lineWidth="1dp"
        app:lineMargin="5dp"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

再Activity中使用它

package cn.wwj.customview
import android.os.Bundle
import android.os.Handler
import android.os.Looper
import androidx.appcompat.app.AppCompatActivity
import cn.wwj.customview.widget.NodePointProcessBar
/**
 * 節(jié)點(diǎn)進(jìn)度Activity
 */
class NodeProgressBarActivity : AppCompatActivity() {
    /**
     * 數(shù)據(jù)結(jié)合
     */
    private val mTextList: List<String> = mutableListOf("提交申請(qǐng)", "商家處理", "寄回商品", "商家退款", "退款成功")
    /**
     * 正在處理的節(jié)點(diǎn)索引結(jié)合
     */
    private var mProgressIndexSet: Set<Int> = mutableSetOf(0, 1,2,3,4,6)
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_node_progress_bar)
        val nodePointPb: NodePointProcessBar = findViewById(R.id.nodePointPb)
        Handler(Looper.getMainLooper()).postDelayed({
            nodePointPb.setNodeData(mTextList, mProgressIndexSet)
        }, 1000)
    }
}