自定义View之SportView

tech2023-03-06  71

private val SPORT_RADIUS = 150.dp class SportView @JvmOverloads constructor( context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0 ) : View(context, attrs, defStyleAttr) { private val mPaint = Paint(Paint.ANTI_ALIAS_FLAG) private val text = "aaaa" //存储文字边界 private val bounds = Rect() private val fontMetrics = Paint.FontMetrics() @RequiresApi(Build.VERSION_CODES.LOLLIPOP) override fun onDraw(canvas: Canvas) { super.onDraw(canvas) //绘制圆环 mPaint.color = Color.GRAY mPaint.style = Paint.Style.STROKE mPaint.strokeWidth = 20.dp canvas.drawCircle((width/2).toFloat(), (height/2).toFloat(),SPORT_RADIUS,mPaint) //绘制进度条 mPaint.color = Color.GREEN mPaint.strokeCap = Paint.Cap.ROUND canvas.drawArc(width/2- SPORT_RADIUS,height/2- SPORT_RADIUS,width/2+ SPORT_RADIUS,height/2+ SPORT_RADIUS,-90f,225f,false,mPaint) //绘制文字 mPaint.style = Paint.Style.FILL mPaint.textSize = 100.dp //设置文字左右居中 mPaint.textAlign = Paint.Align.CENTER //文字默认会在纵向基准线baseline的上方 // mPaint.getTextBounds(text,0,text.length,bounds) // Log.d("SportView",bounds.toString()) //适用于静态的文字居中效果 // val centerY = height/2f-(bounds.top+bounds.bottom)/2 //ascent 文字核心部分的顶部 // descent 文字核心部分的底部 // top bottom 文字顶部和底部的极限值 //动态文字居中策略,为了防止文字跳动 mPaint.getFontMetrics(fontMetrics) //核心部分居中 val centerY = height/2f - (mPaint.ascent()+mPaint.descent())/2 canvas.drawText(text,width/2f,centerY,mPaint) } }

总结

静态的文字居中效果 使用height/2f-(bounds.top+bounds.bottom)/2动态文字居中策略,为了防止文字跳动 使用 height/2f - (mPaint.ascent()+mPaint.descent())/2
最新回复(0)