DensityUtil(尺寸转化+状态栏高度)

/**
 * @author mao
 */
object DensityUtil {
    /**
     * 根据手机的分辨率从 dp 的单位 转成为 px(像素)
     */
    @JvmStatic
    fun dip2px(context: Context, dpValue: Float): Int {
        val scale = context.resources.displayMetrics.density
        return (dpValue * scale + 0.5f).toInt()
    }
    @JvmStatic
    fun px2dip(context: Context, pxValue: Float): Int {
        val scale = context.resources.displayMetrics.density
        return (pxValue / scale + 0.5f).toInt()
    }
    @JvmStatic
    fun px2sp(context: Context, pxValue: Float): Int {
        val fontScale = context.resources.displayMetrics.scaledDensity
        return (pxValue / fontScale + 0.5f).toInt()
    }
    @JvmStatic
    fun sp2px(context: Context, spValue: Float): Int {
        val fontScale = context.resources.displayMetrics.scaledDensity
        return (spValue * fontScale + 0.5f).toInt()
    }

    /**
     * 获取竖屏下状态栏高度
     */
    @JvmStatic
    fun getStatusBarHeightPortrait(context: Context): Double {
        var statusBarHeight = 0
        //获取status_bar_height_portrait资源的ID
        val resourceId = context.resources.getIdentifier("status_bar_height_portrait", "dimen", "android")
        if (resourceId > 0) {
            //根据资源ID获取响应的尺寸值
            statusBarHeight = context.resources.getDimensionPixelSize(resourceId)
        }
        return statusBarHeight.toDouble()
    }
}

SofeKeyboardStateHelper(软件盘监听工具)

/**
*  用法
*  class Activity{
*    ...
*    mKeyboardHelper = SoftKeyboardStateHelper(window.decorView)
*    mKeyboardHelper.registerSoftKeyboardStateListener(...)
*  }
**/
class SoftKeyboardStateHelper(private val decorView: View) : OnGlobalLayoutListener {
    //软件盘是否展开
    private var isSoftKeyboardOpened = false
    //软件盘高度（可能不准确，根据手机的）
    private var softKeyHeight = 0
    //回调监听
    private var softKeyboardStateListener: SoftKeyboardStateListener? = null

    init {
        decorView.findViewById<View>(R.id.content).viewTreeObserver.addOnGlobalLayoutListener(this)
    }

    fun getSoftKeyHeight() = softKeyHeight

    fun registerSoftKeyboardStateListener(softKeyboardStateListener: SoftKeyboardStateListener?) {
        this.softKeyboardStateListener = softKeyboardStateListener
    }

    fun unRegisterSoftKeyboardStateListener() {
        decorView.viewTreeObserver.removeOnGlobalLayoutListener(this)
    }

    override fun onGlobalLayout() {
        val mKeyboardUp: Boolean = isKeyboardShown(decorView)
        if (mKeyboardUp) {
            //键盘弹出
            if (!isSoftKeyboardOpened) {
                val r = Rect()
                decorView.getWindowVisibleDisplayFrame(r)
                val displayHeight = r.bottom - r.top
                val parentHeight: Int = decorView.height
                softKeyHeight = parentHeight - displayHeight

                Log.i("软键盘监听器助手", "展开,parentHeight=${parentHeight},displayHeight = ${displayHeight},softKeyHeight=${softKeyHeight}")
                isSoftKeyboardOpened = true
                softKeyboardStateListener?.onSoftKeyboardOpened()
            }
        } else {
            //键盘收起
            if (isSoftKeyboardOpened) {
                Log.i("软键盘监听器助手", "关闭")
                isSoftKeyboardOpened = false
                softKeyboardStateListener?.onSoftKeyboardClosed()
            }
        }
    }

    private fun isKeyboardShown(rootView: View): Boolean {
        val softKeyboardHeight = 100
        val r = Rect()
        rootView.getWindowVisibleDisplayFrame(r)
        val dm = rootView.resources.displayMetrics
        val heightDiff = rootView.bottom - r.bottom
        return heightDiff > softKeyboardHeight * dm.density
    }

    interface SoftKeyboardStateListener {
        fun onSoftKeyboardOpened()
        fun onSoftKeyboardClosed()
    }
}

GsonUtil(Gson工具类)

/**
 * @Description: Gson工具类
 * @Author: mao
 */
object GsonUtil {

    private val gson by lazy {
        GsonBuilder().create()
    }

    fun toJson(value: Any): String {
        return gson.toJson(value)
    }

    @Throws(JsonSyntaxException::class)
    fun <T> formJson(json:String,clazz: Class<T>): T {
        return gson.fromJson(json,clazz)
    }

    @Throws(JsonSyntaxException::class)
    fun <T> formJson(json:String,type: Type):T{
        return gson.fromJson(json,type)
    }

    @Throws(JsonSyntaxException::class,IllegalStateException::class)
    fun <T> fromJsonList(json: String, clazz: Class<T>): MutableList<T>{
        val mList = mutableListOf<T>()
        val array = JsonParser().parse(json).asJsonArray
        for (elem in array) {
            mList.add(gson.fromJson(elem, clazz))
        }
        return mList
    }
    
    @Throws(JsonSyntaxException::class,IllegalStateException::class)
    fun <T> fromJsonMap(json: String, cls: Class<T>): MutableMap<String, T>{
        val map = mutableMapOf<String, T>()
        val jsonObj = JsonParser().parse(json).asJsonObject
        val entrySet: Set<Map.Entry<String, JsonElement>> = jsonObj.entrySet()
        val iter = entrySet.iterator()
        while (iter.hasNext()){
            val entry  = iter.next()
            map[entry.key] = formJson(entry.value.toString(),cls)
        }
        return map
    }
}

GridSpacingItemDecoration（recycleView网格布局间距）