toolbar实现标题居中

//设置左侧图标之后在调用
fun Toolbar.setTitleCenter(text: String, sub: String? = null) {
    //设置标题
    title = text;subtitle = sub
    var titleWidth = 0
    //完全是心理暗示 正常是标题先初始化 然后是副标题
    var subView: TextView? = null
    forEach { view ->
        if (view is ImageButton && navigationIcon == view.drawable) {
            //如果左边有图标就将titleMarginStart减少 通过打印发现左边有图标的时候titleMarginStart初始化就位10 所以这里减掉
            view.post { titleMarginStart -= view.width + 10 }
        } else if (view is TextView && text == view.text) {
            view.post {
                titleWidth = view.width
                subView?.setParams(width = titleWidth)
                //屏幕宽度的一般减去title的宽度的一般 就是 titleMarginStart
                titleMarginStart += ScreenUtils.getScreenWidth() / 2 - view.width / 2
            }
        } else if (view is TextView && sub == view.text) {
            //副标题内容居中
            view.gravity = Gravity.CENTER
            view.post {
                //设置副标题和主标题一样宽
                if (titleWidth == 0) subView = view else view.setParams(width = titleWidth)
            }
        }
    }
}

fun View.setParams(width: Int? = null, height: Int? = null) {
    val params = layoutParams
    if (width != null) params.width = width
    if (height != null) params.height = height
    layoutParams = params
}