Add user interaction, data captures, sound, and animation to your apps Implement dialog boxes to capture input from the user Build a simple database app that sorts and stores the user s data What do you get with Print? Instant access to your digital eBook copy whilst your Print order...
/** * Elvis操作符 ?: 简化对空值的处理 */ fun testElvis2(input: String?, user: User?) { val b = input?.length ?: -1; user?.save() ?: User().save() }Tip14-运算符重载回到目录Kotlin支持对运算符的重载,这对于对一些对象的操作更加灵活直观。
fun Activity.hideKeyboard(): Boolean { val view = currentFocus view?.let { val inputMethodManager = getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager return inputMethodManager.hideSoftInputFromWindow(view.windowToken, InputMethodManager.HIDE_NOT_ALWAYS) } return false} 通过扩展,...
The code initiates the process of acquiring a token silently. It first clears the text log. Then, it checks if there's an available account; if not, it displays a toast message indicating this and exits. Next, it extracts scopes from text input, converts them to lowercase, and splits ...
intent(): This function takes the input from the user (i.e. UI events, like click events) and translate it to “something” that will be passed as parameter tomodel()function. This could be a simple string to set a value of the model to or more complex data structure like an Object...
())}//直接处理行file.forEachLine(action=::println)//读取为bytesval bytes:ByteArray=file.readBytes()println(bytes.joinToString(separator=""))//直接处理Reader或InputStreamval reader:Reader=file.reader()val inputStream:InputStream=file.inputStream()val bufferedReader:BufferedReader=file.bufferedReader...
3306/mydb", "user", "pass", "com.mysql.jdbc.Driver") sql.eachRow("SELECT * FROM my_...
mHomeWorkId=intent.getStringExtra(INPUT_HOME_WORK_ID)?:"" 1.2.2、条件判断问题 看下面例子: 代码语言:javascript 复制 varmUser:User?=nullif(mUser?.grade!=-1){//做一些操作} 上面代码看上去很简单,定义了一个 User类型的属性mUser,是可以为null的。在if条件中通过判断年级是否等于-1 来做一下操作。
forms with input components bound to state objects. The forms are built by using a declarative Kotlin syntax and follow the official IntelliJ Platform UI conventions described in theUI Guidelines. The library is written inKotlinand makes it easy to develop user interfaces likedialogsandsettings ...
The first task, handling character input from the user, takes 8 ms to execute. The next task, updating the view, is part of an animation. In order to look smooth, the animation needs to be updated at least 24 times per second. The third task, though, handling a user click, takes 22...