# Some Kotlin Code For Android **URL:** \ **Category:** Android\ **Created:** [December 18, 2019, 3:02am UTC](https://discuss.kotlinlang.org/t/some-kotlin-code-for-android/15488 "2019-12-18T03:02:09Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![lorss](https://avatars.discourse-cdn.com/v4/letter/l/3ec8ea/32.png) [@lorss](https://discuss.kotlinlang.org/u/lorss)\ **Post date:** [December 18, 2019, 3:02am UTC](https://discuss.kotlinlang.org/t/some-kotlin-code-for-android/15488/1 "2019-12-18T03:02:09Z")
[Click to see Source Code kotlinx-android](https://github.com/runningmessage/kotlinx-android/blob/master/README.md) # ============== ## kotlinx-widget AbsSwipeRefreshLayout\: ``` rewite SwipeRefreshLayout : 1. support pull down to refresh and enable to custom pull refresh anim: 支持下拉刷新自定义刷新动画 2. support show remind pop view after pull refresh: 支持刷新完成后弹窗提醒 ``` LoadMoreRecyclerAdapter\: ``` custom RecyclerView.Adapter : 1. support pull up load more: 支持上拉加载更多 ``` ## kotlinx-common ActivityExt: ``` Activity.contentView 1. return the content view set by [Activity.setContentView] ``` ```java Activity.startActivityForResult(requestCode, bundle) // same with below Activity.startActivityForResult(Intent(context, MyActivity::class.java), requestCode, bundle) ``` ```java Activity.startActivityForResult(requestCode, bundle){ action = "com.action.xxx" putExtra("key", "value") } // same with below val intent = Intent(context, MyActivity::class.java).apply{ action = "com.action.xxx" putExtra("key", "value") } Activity.startActivityForResult(intent, requestCode, bundle) ``` AndroidExt: ```java /** Do something depending on android sdk, for compatibility */ /** 判断安卓SDK版本后 执行代码, 兼容性 */ ifSdk(16, 19, 29) { //do something if Build.VERSION.SDK_INT is one of 16, 19, 29 } other { //otherwise, do other thing } ifNotSdk(16, 19, 29) { //do something if Build.VERSION.SDK_INT is not 16, 19 or 29 } other { //otherwise, do other thing } fromSdk(16) { //do something if Build.VERSION.SDK_INT >= 16 } other { //otherwise, Build.VERSION.SDK_INT < 16, do other thing } toSdk(16) { //do something if Build.VERSION.SDK_INT <= 16 } other { //otherwise, Build.VERSION.SDK_INT > 16, do other thing } afterSdk(16) { //do something if Build.VERSION.SDK_INT > 16 } other { //otherwise, Build.VERSION.SDK_INT <= 16, do other thing } untilSdk(16) { //do something if Build.VERSION.SDK_INT < 16 } other { //otherwise, Build.VERSION.SDK_INT >= 16, do other thing } ``` BitmapExt: ``` Bitmap?.createRoundedCornerBitmap 1. create a new rounded corner bitmap, basing on the current bitmap: 基于当前 Bitmap 创建一个带圆角的 Bitmap ``` ContextExt: ``` Context?.toastShort(msg) Context?.toastShort(resId) Context?.toastLong(msg) Context?.toastLong(resId) Context.dpToPx(dp) 1. cast the [dp] dip into px unit Context.pxToDp(px) 1. cast the [px] px into dip unit Context.screenWidth() 1. get the screen width pixels , same as [Context.getResources].[getDisplayMetrics].[widthPixels] Context.screenWidthShort() 1. return the smaller between [screenWidth] and [screenHeight] Context.screenWidthX() 1. return the [screenWidthShort] if current is orientation portrait, otherwise the [screenHeightLong] Context.screenHeight() 1. get the screen height pixels , same as [Context.getResources].[getDisplayMetrics].[heightPixels] Context.screenHeightLong() 1. return the larger between [screenWidth] and [screenHeight] Context.screenHeightY() 1. return the [screenHeightLong] if current is orientation portrait, otherwise the [screenWidthShort] ``` ```java Context.startActivity() // same with below Context.startActivity(Intent(context, MyActivity::class.java)) ``` ```java Context.startActivity{ action = "com.action.xxx" putExtra("key", "value") } // same with below val intent = Intent(context, MyActivity::class.java).apply{ action = "com.action.xxx" putExtra("key", "value") } Context.startActivity(intent) ``` HandlerExt: ```java Handler.postDelayed(delay){ // do something } ``` NoLeakListenerFunction1: ``` wrap the Listener implementing interface , which only has one callback method, **Avoid Memory Leak !!!** 包装 只实现 有一个单独方法的接口 的监听器， 并返回代理对象， ***避免内存泄漏 !!!*** ``` TextViewExt: ``` TextView.addEllipsis: 1. add "…" after the end of text: 在 TextView 显示的文本末尾添加省略号( … ) ``` ThreadExt: ``` object UiThreadHandler isMainThread() ``` ```java runOnNewThread { // do something in a new thread } // same with below Thread{ // do something in a new thread }.start() ``` ```java postOnNewThread(1000) { // do something in a new thread after 1000 milliseconds } // same with below val handler = Handler(HandlerThread("HandlerThread-${nextThreadNum()}").apply { start() }.looper) handler.postDelayed(1000) { try { // do something in a new thread after 1000 milliseconds } catch (ignored: Exception) { } finally { (Thread.currentThread() as? HandlerThread)?.let { thread -> fromSdk(18) { thread.quitSafely() } other { thread.quit() } } } } ``` ```java postOnCurrentThread(1000) { // do something in current thread after 1000 milliseconds } // same with below Handler().postDelayed(1000) { // do something in current thread after 1000 milliseconds } ``` ```java runOnUiThread(target) { // do something in ui thread, // and try to associate with the lifecycle for target , when target is not null } postOnUiThread(target, 1000){ // do something in ui thread after 1000 milliseconds, // and try to associate with the lifecycle for target , when target is not null } ``` ``` Runnable.runOnUiThread(target) 1. immediately run the task, if current is on UI thread 2. otherwise, to post the task into run queue, or maybe a ui thread handler Runnable.postOnUiThread(target, delay) 1. post the task into run queue, or maybe a ui thread handler; and the task will be to run after [delay] milliseconds , even if the [delay] is less than 0, it is still waiting the run queue to call running ``` ViewExt: ``` View.layoutLeftMargin: 1. return the leftMargin of the layoutParams for the current View, if exists , otherwise return null 2. set the leftMargin of the layoutParams for the current View, and reset the layoutParams View.layoutRightMargin: 1. return the rightMargin of the layoutParams for the current View, if exists , otherwise return null 2. set the rightMargin of the layoutParams for the current View, and reset the layoutParams View.layoutTopMargin: 1. return the topMargin of the layoutParams for the current View, if exists , otherwise return null 2. set the topMargin of the layoutParams for the current View, and reset the layoutParams View.layoutBottomMargin: 1. return the bottomMargin of the layoutParams for the current View, if exists , otherwise return null 2. set the bottomMargin of the layoutParams for the current View, and reset the layoutParams View.layoutWidth: 1. return the width of the layoutParams for the current View, if exists , otherwise return null 2. set the width of the layoutParams for the current View, and reset the layoutParams View.layoutHeight: 1. return the height of the layoutParams for the current View, if exists , otherwise return null 2. set the height of the layoutParams for the current View, and reset the layoutParams ``` ```java View.postDelayed(delay){ // do something } ``` ViewGroupExt: ``` ViewGroup.views 1. the list of child view ViewGroup.firstView 1. the first child view ViewGroup.lastView 1. the last child view ```