kotlin constructors

Kotlin's control flow is the same as in other languages, order, branching, loopingThere are two types of branching, if-else and when (similar to switch in Java).If statement:Operation Result:The case statement in Java not only supports integer values, the latest JVM also supports strings, kotlin when statements are more powerful, switch variables can even be various types such as Double,array, in other words when statements are more powerful than swit

Forward pushDesign PatternsSimple Factory mode (Java and Kotlin Edition)Kotlin Basic KnowledgeKotlin first lesson: Starting with Java comparisonKotlin Introductory Lesson II: Collection OperationsKotlin Introductory Lesson Three: Data typesFirst attempt to implement Android projects with Kotlin1. DefinitionThe factory method pattern (Factory mode), also known as the factory pattern, is called the virtual Co

Using the Kotlin-kapt pluginRely on Java annotationprocessor instead of KAPTWhen using the control binding use, online search method, do not know by which guy with the pit.Error usage @BindView (r.id.tv_title) lateinit var tvtitle:textviewresult in the use of the control, there is no binding success, errorKotlin. Uninitializedpropertyaccessexception:lateinit property title had not been initializedCorrect useTv_title.settextcolor (color.red)Tv_title.s

Android-kotlin in fragment get ViewoverviewWhen using fragment, Butterknife was used to get the view but it went wrong, and then it was used to get the view directly using the Kotlin import layout, but it was wrong.ReasonThe reason is that the view is called in the Fragment Oncreateview method, which is obviously not possible because the view is not bound to the Fragment. So the initialization code can be p

1. ThreadJava notationNew Thread (New Runnable () {@Overridepublic void Run () {}}). Start (); Kotlin notationThread (Runnable { }). Start () 2, HandlerJavaPrivate Handler handler=new Handler (New Handler.callback () {@Overridepublic boolean handlemessage (Message msg) {Switch (msg.what) {Case 0:BreakDefaultBreak}return false;}}); KotlinPrivate Val Handler=handler (handler.callback{msg->When (Msg.what) {0->{}else->{}}False}) 3, SetonclicklistenerJavaB

A sealed class is used to represent a restricted class inheritance structure: When a value is a finite set ofType, and cannot have any other type. In a sense, they are extensions of the enumeration class: A collection of values for the enumeration typeis restricted, but there is only one instance of each enumerated constant, and the sealed classCan have multiple instances that can contain states. To declare a sealed class, you need to add the sealed modifier before the class name. Although seale

Defining local Variables Assign only one time (read-only) Local variables: Val a:int = 1 val b = 1//' Int ' type is inferred val c:int//type required when No. initializer is provided c = 1//definite assignment Variable variable var x = 5//' Int ' type is inferred x + = 1 Properties and Fields Defining propertiesYou can have properties in a class of Kotlin. These can be declared as mutable, using the Val keyword var keyword or read-only. p

Kotlin Object expressions and object declarations Kotlin uses object expressions and object declarations to implement an object that creates a class that makes minor changes to a class, and does not need to declare a new subclass. an object expression An object that implements an anonymous inner class through an object expression is used in the parameters of the method: Window.addmouselistener (Object:mous

constructor is calleddestructor is called. 2//parameter B is destructorDefault constructor is called. Call the default constructor construct T2Constructor is Called.3//with 3 construction parameter BCopy Constructor is Called.3//using a B copy to construct a temporary objectdestructor is called. 3//parameter B is destructorThe operator "=" is Called.3//call = operator to initialize T2, at which point the assignment operator is calleddestructor is called. 3//Temporary object is destructordestruc

Code and Explanation:#include "stdafx.h" #include Output and interpretationA piece of code causes a deep understanding of C + + constructors, destructors, copy constructors, operator overloading

with parameters { cout } B (b b)//copy (copy) constructors { data = B.data; cout } b operator = (const B b)//overloading of assignment operators { This->data = B.data; cout return *this; } ~b ()//destructor { cout } Private int data; }; function, the argument is a type B object, and the return value is also an object of type B b Fun (b b) { return b; } Test function int _tmain (int argc, _tchar* argv[]) { Fun (1); cout

Experience: Anko + Kotlin and ankotlin ● Dependency: compile 'org. jetbrains. anko: 0.10.0' ● Interface: Import android. view. viewimport org. jetbrains. anko. * import org. jetbrains. anko. sdk25.coroutines. onClickclass MainActivityUI: AnkoComponent ● Activity： import android.os.Bundleimport android.support.v7.app.AppCompatActivityimport org.jetbrains.anko.setContentViewclass MainActivity : AppCompatActivity() { override fun onCreate(savedInstan

　As a result of the recent online search for a lot of Android connection to the HTTP method, but 2013 years ago, the method can not be used now, or error, or abandoned, the years left behind the things can only be sorted by themselves.It's really simple, just a httputil generic class. Can implement get and post method, other things, inside can be arbitrarily changed, basically so.parameter, I used a strurlpath URL, params key-value pair, encode code (such as Utf-8).　　Package Utilimport Android.o

Google's official support, experience.XmlXML version= "1.0" encoding= "Utf-8"?>LinearLayoutxmlns:android= "Http://schemas.android.com/apk/res/android"Xmlns:app= "Http://schemas.android.com/apk/res-auto"Android:layout_width= "Match_parent"Android:layout_height= "Match_parent"android:orientation= "vertical" > TextViewAndroid:id= "@+id/textview"Android:layout_width= "Wrap_content"Android:layout_height= "Wrap_content"Android:text= "Hello world!" /> ButtonAndroid:id= "@+id/button"Android:

()) { + querybranchiterator.next (). Apply { - Sqlbuilder.append (Build (Dict[key])) the }Bayi } the } the -Val queryresults = arraylist() - SQL_SERVER_DATA_SOURCE.connection.apply { the preparestatement (Sqlbuilder.tostring ()). Apply { the //Set Query Parameters the varParamindex =1 theQuerybranches.foreach {Querybranch -val param =Dict[querybranch.key] the if(Querybranch.dosetparameter (param, Paramindex

Kotlin Condition Control an IF expression An If statement contains a Boolean expression and one or more statements. Traditional usage var max = a if (a We can also assign the result of an IF expression to a variable. Val max = if (a > B) { print ("Choose a") a } else { print ("Choose B") b } This also means that I don't need to have a ternary operator like Java, because we can use it to make it simple: Val C = if (condition) a el

Public Fun readbloghtml (blog:string): observable { return Observable.just (blog ), assembleurl (blog)} , readhtml (URL)}}I was a little confused ...And in fact Flatmap is not needed, because Kotlin read the source of the Web page is a word ... Public Fun readhtml (url:string): observable { return Observable.create { - subscriber.onnext (URL). ReadText ()); Subscriber.oncompleted () }}It's better

Antonio LeivaTime: Sep 12, 2016Original link: http://antonioleiva.com/recyclerview-diffutil-kotlin/As you know, the "Support Library 24" includes a new, applicable, and convenient class: Diffutil, which allows you to get rid of the boredom and error of cell changes and updates.If you don't know it yet, you can read Nicola Despotoski's good article about it. This article explains how easy it is to handle it.In fact, the Java language introduced many te

I wrote it once. Kotlin parsing JSON But, it's really bad, it's just erased, and now it's all sorted out again. By the way, record a little problem that has been going on for a long time today.1. Let's start with the simplest.A JSON string: ===== is called jsonstring.{ "code": "$", "MSG": "Success", "debugmsg": "", "result":{ "Data": "1231414"} }Well, how to parse it???You can use a function toFun get_key_string (key:string,jsonstring:string):

visible to the file in which they are located, and cannot be used in files other than the definition of this class protected can be visible to members themselves and their successors (for example, classes and its subclasses) internal to the entire module where the public The least restrictive modifier. This is the default modifier delegate Property A property has some of the same behavior, and using lazy or observable can be fun to reuse. Instead of declaring those same code over and over again