classMyClass{lateinitvarname:StringfuninitializeName(name:String){this.name=name}fundisplayName(){if(::name.isInitialized){println("名字:$name")}else{println("名字尚未初始化!")}}}funmain(){valmyClass=MyClass()myClass.displayName()// 可能会报错:Lateinit property name has not been initialized}...
运行 复制 This variable must either have a type annotation or be initialized 3. 显式类型声明 ( var 变量名 : 变量类型 (= 变量值) | var age : Byte = 27 | var time_stap : Long | var name : String = “Joe” ) 显示类型声明 : 1.格式 : var 变量名 : 变量类型 (= 变量值) ; 2....
v: View?, group: ViewGroup?): View { val inflater = LayoutInflater.from(ctx) var view = v if (view == null) { view = inflater.inflate( R.layout.adapter_navigation_drawer, null ) as LinearLayout } val item = items[position]
Intrinsics.checkNotNullParameter(var1,"<set-?>");this.sequence = var1; } }publicstaticvoidthrowUninitializedPropertyAccessException(String propertyName){ throwUninitializedProperty("lateinit property "+ propertyName +" has not been initialized"); } 可以看到相比于非空可变成员变量,它在get方法的实现内...
会报kotlin.UninitializedPropertyAccessException: lateinit property test has not been initialized 除了使用lateinit外还可以使用by lazy {}效果是一样的: private val test by lazy { "haha" } private fun switchFragment(position: Int) { if (test == null) { LogUtil.e("@@@", "test is null") }...
check(test) } } 会报kotlin.UninitializedPropertyAccessException: lateinit property test has not been initialized 除了使用lateinit外还可以使用by lazy {}效果是一样的: privatevaltestbylazy {"haha"}privatefunswitchFragment(position:Int){if(test ==null) { ...
非空对象要么在声明时就赋值,要么在方法调用前赋值;否则未经初始化就调用该对象的方法,Kotlin会像语法错误那样提示这里“Variable *** must be initialized”。至于可以为空的对象,可于声明之时在类型后面加个问号,如同上一篇文章声明可空字符串数组的代码“val poem2Array:Array<String?> = ***”,只声明一个可...
override fun toString(): String = if (isInitialized()) value.toString() else "Lazy value not initialized yet." private fun writeReplace(): Any = InitializedLazyImpl(value) } 问题分析: DCL存在多线程安全问题,我们都知道线程安全主要来自主存和工作内存数据不一致以及重排序(指令重排序或编译器重排序造...
()_value=typedValue//并把这个实例对象保存在_value中initializer=nulltypedValue}}}overridefunisInitialized():Boolean=_value!==UNINITIALIZED_VALUEoverridefuntoString():String=if(isInitialized())value.toString()else"Lazy value not initialized yet."privatefunwriteReplace():Any=InitializedLazyImpl(value)}...
If you hold a reference to an instance of Lazy, isInitialized() allows you to check whether it has already been initialized (and you can obtain such instance with reflection from a delegated property). To check whether a lateinit property has been initialized, you can use property::isInitialize...