更换界面

前面的列表只是显示了数据，太难看了，现在来优化一下
创建adapter的item布局文件item_forecast.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="8dp"
    android:background="?attr/selectableItemBackground"
    android:gravity="center_vertical"
    android:orientation="horizontal">
    <ImageView
        android:id="@+id/icon"
        android:layout_width="48dp"
        android:layout_height="48dp"
        tools:src="@mipmap/ic_launcher"/>
    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:layout_marginLeft="16dp"
        android:layout_marginRight="16dp"
        android:orientation="vertical">
        <TextView
            android:id="@+id/date"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textAppearance="@style/TextAppearance.AppCompat.Medium"
            tools:text="May 14, 2015"/>
        <TextView
            android:id="@+id/description"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textAppearance="@style/TextAppearance.AppCompat.Caption"
            tools:text="Light Rain"/>
    </LinearLayout>
    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal"
        android:orientation="vertical">
        <TextView
            android:id="@+id/maxTemperature"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="@style/TextAppearance.AppCompat.Medium"
            tools:text="30"/>
        <TextView
            android:id="@+id/minTemperature"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="@style/TextAppearance.AppCompat.Caption"
            tools:text="15"/>
    </LinearLayout>
</LinearLayout>

每一个item需要显示小图标，所以，需要在data类中加入图标url：

data class Forecast(val date: String, val description: String, val high: Int, val low: Int,val iconUrl: String)

更改ForecastDataMapper.kt

    private fun convertForecastItemToDomain(forecast: Forecast): ModelForecast {
        return ModelForecast(convertDate(forecast.dt), forecast.weather[0].description, forecast.temp.max.toInt(), forecast.temp.min.toInt(), generateIconUrl(forecast.weather[0].icon))
    }

private fun generateIconUrl(iconCode: String): String = "http://openweathermap.org/img/w/$iconCode.png"

给天气列表item加上点击事件：

public interface OnItemClickListener {
    operator fun invoke(forecast: Forecast)
}

提一下listener的调用，当方法名为invoke时，可以直接这样写

temClick.invoke(forecast)
itemClick(forecast)

在看看更改过的adapter：

class ForecastListAdapter(val weekForecast: ForecastList, val itemClick: OnItemClickListener) : RecyclerView.Adapter<ForecastListAdapter.ViewHolder>() {
    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
        val view = LayoutInflater.from(parent.ctx).inflate(R.layout.item_forecast, parent, false)
        return ViewHolder(view, itemClick)
    }

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
        holder.bindForecast(weekForecast[position])
    }

    override fun getItemCount(): Int = weekForecast.size()

    class ViewHolder(val view: View, val itemClick: OnItemClickListener) : RecyclerView.ViewHolder(view) {
        private val iconView: ImageView
        private val dateView: TextView
        private val descriptionView: TextView
        private val maxTemperatureView: TextView
        private val minTemperatureView: TextView

        init {
            iconView = view.find(R.id.icon)
            dateView = view.find(R.id.date)
            descriptionView = view.find(R.id.description)
            maxTemperatureView = view.find(R.id.maxTemperature)
            minTemperatureView = view.find(R.id.minTemperature)
        }

        fun bindForecast(forecast: Forecast) {
            with(forecast) {
                Picasso.get().load(iconUrl).into(iconView)
                dateView.text = date
                descriptionView.text = description
                maxTemperatureView.text = "${high.toString()}"
                minTemperatureView.text = "${low.toString()}"
                itemView.setOnClickListener { itemClick(forecast) }
            }
        }
    }
}

最后就是调用了，在MainActivity中：

        doAsync() {
            val result = RequestForecastCommand("94043").execute()
            uiThread {
                forecastList.adapter = ForecastListAdapter(result,
                        object : OnItemClickListener{
                            override fun invoke(forecast: Forecast) {
                                toast(forecast.date)
                            }
                        })
            }
        }