二、@objc应用于变量是为了能够让变量表达为keypath字符串,进而使用kvc功能。 class Person: NSObject { @objc var name: String @objc var friends: [Person] = [] @objc var bestFriend: Person? = nil init(name: String) { self.name = name } } let gabrielle = Person(name: "Gabrielle") le...
@objc func tappedButton(_ sender: UIButton?) { print("tapped button") } required init?(coder: NSCoder) { super.init(coder: coder) } 二、@objc应用于变量是为了能够让变量表达为keypath字符串,进而使用kvc功能。 class Person: NSObject { @objc var name: String @objc var friends: [Person]...
var其实在你设置它的变量a的值的那一刻起,它的类型就确定了。这点你可以在VS里,在var上面查看定义,就可以看到例子里面a的类型就是Int32。如果你把变量a赋值为字符串类型,那么它变量a的类型就是string。严格来说还没到编译阶段,在编译器VS里面就被识别了类型。 而dynamic则不同,它类似于public,static。无法查看...
dynamic vs. System.Object Until the .NET Framework 4, having a method return different types according to different conditions was possible only by resorting to a common base class. You’ve probably solved this problem by resorting to System.Object. A function that returns System.Object makes av...
c) There are new scenarios and benefits, of course. But once again, considering that "object" was always there, you should not be afraid that someone using dynamic objects will break your code. I am not encouraging "everybody" to start using "dynamic" everywhere in the code. Bu...
.method private hidebysig static void Main(string[] args) cil managed { .entrypoint // Code size 396 (0x18c) .maxstack 12 .locals init ([0] object dynamicValue, [1] class [Microsoft.CSharp]Microsoft.CSharp.RuntimeBinder.CSharpArgumentInfo[] CS$0$0000) IL_0000: nop IL_0001: call val...
与var 关键字不同,定义为dynamic的对象可以在运行期间改变其类型。注意在使用var关键字时,对象类型的确定会证迟。类型一旦确定,就不能改变。动态对象的类型可以改变,而且可以改变影次,这不同于把对象的类型事转换为另一种类型。在强制转换对象的类型时,是用另一种兼容的类聚们建一个新对象。如,不能把int强制转...
ICollection(KeyValuePair(String, Object)).Count Property ICollection(KeyValuePair(String, Object)).IsReadOnly Property IDictionary(String, Object).Item Property IDictionary(String, Object).Keys Property IDictionary(String, Object).Values Property ExpandoObject Events GetIndexBinder Class G...
Adds the ability to access run-time information about an object's class when deriving a class fromCObject. คัดลอก DECLARE_DYNAMIC(class_name ) Parameters class_name The actual name of the class. Remarks Add theDECLARE_DYNAMICmacro to the header (.h) module for the class, ...
这里传入的session就是当前文档的所有内容,而completionSets则是VS默认的行为执行完之后的结果集。 因为一般的对象都是继承自object的,所以输入.之后必然会有自动完成的内容,也就是completionSets.Count必定是大于0的,而dynamic则不然,如图 dynamic默认情况下是没有任何自动完成列表的。我们就可以利用这个,来判断是不是...