在网页上看到这种打分效果,想着android里咋实现。
第一想法就是RatingBar了,它背景默认是一排星星,而这里需要数字1到10的,系统的肯定做不到,那么稍微改下就可以吧?
为啥在系统的RatingBar上改?
为了偷懒,不用处理触摸事件.我们只需要在onDraw里画上我们要的就行了
前提知识:
android:numStars="10"
android:stepSize="1"
android:rating="4"
为了省事,numStarts就当做我们的score了,rating就是当前的打分,stepSize我们会默认设置为1,这样每次滑动间隔就是1分了.
还有默认的星星,再最后我们会把它设置为null,这样就只会显示我们自定义的了。
默认的主题,Appcompat包下的,材料主题可能有区别,只是说明下,默认的高度是固定的,最小最大值一样,这个我们需要修改下,要不可能没法把score的item弄成正方形.
<style name="Widget.RatingBar">
<item name="indeterminateOnly">false</item>
<item name="progressDrawable">@drawable/ratingbar_full</item>
<item name="indeterminateDrawable">@drawable/ratingbar_full</item>
<item name="minHeight">57dip</item>
<item name="maxHeight">57dip</item>
<item name="thumb">@null</item>
<item name="mirrorForRtl">true</item>
</style>
step 1
首先我们要根据容器的宽度,计算每个item的宽
每个score之间是有个间隔的,我们定义个固定值,然后算下有几个
假如总的score count是10,那么space的个数就是10-1,我们只需要宽度减去这些space的宽,然后除以score的个数,就知道每个的宽度的,很简单
因为RatingBar有固定的高度的,不符合我们的需求,所以下边根据item的宽,修改了容器的高度.
override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec)
starSize=(measuredWidth-(numStars-1)*spaceWidth)/numStars
rect.set(0f,0f,starSize,starSize)//我这里每个score的item是个正方形的
setMeasuredDimension(measuredWidth,starSize.toInt())
paintText.getTextBounds("10",0,2,textBounds)
}
step 2
然后就是循环绘制那10个item的背景以及文字了.
override fun onDraw(canvas: Canvas) {
super.onDraw(canvas)
if(width==0||height==0){
return
}
rectTemp.set(rect)
(0 until numStars).forEach {
rectTemp.offsetTo((starSize+spaceWidth)*it,0f)
val isPre=it<rating
paintBG.apply {
color=if(isPre) Color.BLUE else Color.GRAY
}
canvas.drawRect(rectTemp,paintBG)
paintText.apply {
color=if(isPre) Color.WHITE else Color.BLACK
}
canvas.drawText("${it+1}",rectTemp.centerX(),rectTemp.centerY()+textBounds.height()/2,paintText)
}
}
step 3
添加的参数
就是4种颜色,以及文字大小,间距大小
<declare-styleable name="ScoreRatingBar">
<attr name="ScoreTextNormalColor" format="color"/>
<attr name="ScoreTextCheckedColor" format="color"/>
<attr name="ScoreItemNormalColor" format="color"/>
<attr name="ScoreItemCheckedColor" format="color"/>
<attr name="ScoreTextSize" format="dimension"/>
<attr name="ScoreItemSpace" format="dimension"/>
</declare-styleable>
布局
红框四个属性是必须的
最大高度的值随便弄个大点的就行,实际高度是根据宽度算出来的,保证item是正方形
progressDrawalbe 弄成空,就是隐藏默认的星星
numstarts:可以当做最大分数
rating:当前分数
image.png
源码
import android.content.Context
import android.graphics.*
import android.graphics.drawable.ColorDrawable
import android.util.AttributeSet
import androidx.appcompat.widget.AppCompatRatingBar
import com.mitac.app2020.R
class ScoreRatingBar : AppCompatRatingBar {
constructor(context: Context) : super(context)
constructor(context: Context, attrs: AttributeSet?) : super(context, attrs) {
init(context, attrs, 0)
}
constructor(context: Context, attrs: AttributeSet?, defStyleAttr: Int) : super(
context,
attrs,
defStyleAttr
) {
init(context, attrs, defStyleAttr)
}
private fun init(context: Context, attrs: AttributeSet?, defStyleAttr: Int) {
stepSize = 1f
val a = context.obtainStyledAttributes(attrs, R.styleable.ScoreRatingBar, defStyleAttr, 0)
scoreTextSize = a.getDimensionPixelSize(R.styleable.ScoreRatingBar_ScoreTextSize, scoreTextSize);
spaceWidth = a.getDimensionPixelSize(R.styleable.ScoreRatingBar_ScoreItemSpace, spaceWidth)
textColorNormal =
a.getColor(R.styleable.ScoreRatingBar_ScoreTextNormalColor, textColorNormal)
textColorChecked =
a.getColor(R.styleable.ScoreRatingBar_ScoreTextCheckedColor, textColorChecked)
itemColorNormal =
a.getColor(R.styleable.ScoreRatingBar_ScoreItemNormalColor, itemColorNormal)
itemColorChecked =
a.getColor(R.styleable.ScoreRatingBar_ScoreItemCheckedColor, itemColorChecked)
a.recycle()
paintText.textSize=scoreTextSize.toFloat()
}
var scoreTextSize = 30
val rectTemp = RectF()//临时rect,初始化为第一个score item的位置,后边的进行平移即可
var spaceWidth = 10;//每个score item之间的间隔距离
val rect = RectF()//first score item rect
var starSize = 0f//每个score item的宽度
val textBounds = Rect()//计算的文字的范围
val paintBG = Paint().apply {//画背景的
style = Paint.Style.FILL
}
var textColorNormal = Color.BLACK
var textColorChecked = Color.WHITE
var itemColorNormal = Color.GRAY
var itemColorChecked = Color.DKGRAY
val paintText = Paint().apply {//画文字的
textAlign = Paint.Align.CENTER
}
override fun onDraw(canvas: Canvas) {
super.onDraw(canvas)
if (width == 0 || height == 0) {
return
}
rectTemp.set(rect)
(0 until numStars).forEach {
rectTemp.offsetTo((starSize + spaceWidth) * it, 0f)
val isPre = it < rating
paintBG.apply {
color = if (isPre) itemColorChecked else itemColorNormal
}
canvas.drawRect(rectTemp, paintBG)
paintText.apply {
color = if (isPre) textColorChecked else textColorNormal
}
canvas.drawText(
"${it + 1}",
rectTemp.centerX(),
rectTemp.centerY() + textBounds.height() / 2,
paintText
)
}
}
override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec)
paintText.getTextBounds("10", 0, 2, textBounds)
starSize = (measuredWidth - (numStars - 1) * spaceWidth) / numStars.toFloat()
rect.set(0f, 0f, starSize, starSize)
setMeasuredDimension(measuredWidth, starSize.toInt())
}
}
效果图
image.png
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