EditText hint支持图标

兼容21及以下版本

fun EditText.setHintImageSpan(hintTips: String?, drawable: Int) {

val draw = ContextCompat.getDrawable(context, drawable)

draw?.setBounds(0, 0, draw.intrinsicWidth, draw.intrinsicHeight)

val span = CenterAlignImageSpan(draw)

val spannableBuilder = SpannableStringBuilder()

spannableBuilder.append("* ").append(hintTips)

spannableBuilder.setSpan(span, 0, 1, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE)

hint = spannableBuilder

}