SimpleDateFormat

函數System.currentTimeMillis()可取得當前系統時間
但此格式爲自1970/01/01 00:00:00.000到當前時間的毫秒
使用爲SimpleDateFormat加上對應的pattern,對System.currentTimeMillis()做format
而且format後就是String格式

tv_currentTime.text = SimpleDateFormat("MM月dd日  HH:MM").format(System.currentTimeMillis())

若希望個位數的月/日前面不要顯示0,可以改用Calendar直接取得Int再轉toString()
不過要注意Calendar.MONTH的12個月是從0-11,所以須再加1

        val calendar = Calendar.getInstance()
        val month = calendar.get(Calendar.MONTH)
        val day = calendar.get(Calendar.DAY_OF_MONTH)

        tv_currentTime.text =
            (month + 1).toString() + "月" + day.toString() + "日" + SimpleDateFormat(" HH:MM").format(
                System.currentTimeMillis()
            )

SearchView

先簡單用個自訂的editText確認一下資料可取出

要在上方的action bar建立search,須要先建立屬於menu的xml

在layout新增resource,file跟directory name都使用menu

定義menu中的內容search item

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    tools:context=".ui.home.activities.TransactionSearchActivity">
    <item
        android:id="@+id/action_search"
        android:icon="@android:drawable/ic_menu_search"
        android:title="Search"
        app:actionViewClass="android.widget.SearchView"
        app:showAsAction="always" />
</menu>

預覽

然後要在MainActivity override onCreateOptionsMenu
再建立searchView的object也須要override二個函數

    override fun onCreateOptionsMenu(menu: Menu?): Boolean {
        menuInflater.inflate(R.menu.menu,menu)
        val searchItem = menu?.findItem(R.id.action_search)
        if(searchItem != null){
            val searchView = searchItem.actionView as SearchView
            searchView.setOnQueryTextListener(object : SearchView.OnQueryTextListener{
                override fun onQueryTextSubmit(query: String?): Boolean {
                    TODO("Not yet implemented")
                }

                override fun onQueryTextChange(newText: String?): Boolean {
                    TODO("Not yet implemented")
                }
            })
        }
        return super.onCreateOptionsMenu(menu)
    }

這樣就不用editText了,把搜尋的程式寫入onQueryTextChange()中

                override fun onQueryTextChange(newText: String?): Boolean {
                    if(newText!!.isNotEmpty()){
                        val search = newText
                        weatherList.forEach {
                            if (it.locationName.contains(search)) {
                                tv_city.text = it.toString()
                            }
                        }
                    }
                    return true
                }

參考
https://developer.android.com/guide/topics/search/search-dialog.html
https://medium.com/@prasanthvel/android-searchview-in-actionbar-androidx-and-kotlin-3467ca8e6a14