android 可以拖动的圆形 进度条

https://blog.csdn.net/u010134293/article/details/49643299

<declare-styleable name="RoundProgressBar">
    <attr name="roundColor" format="color"/>
    <attr name="roundProgressColor" format="color"/>
    <attr name="roundWidth" format="integer"/>
    <attr name="textColor" format="color"/>
    <attr name="textSize" format="dimension"/>
    <attr name="imageMax" format="integer"/>
    <attr name="pointRadius" format="integer"/>
    <attr name="pointWidth" format="integer"/>
</declare-styleable>