1. 解释“cannot use mutating member on immutable value”错误的含义 “cannot use mutating member on immutable value”错误意味着你尝试在一个不可变值上调用一个会修改该值的成员方法。在Swift编程语言中,如果一个方法会修改其所属对象的实例变量,那么这个方法需要被标记为mutating。
Cannot use mutating member on immutable value: 'self' is immutable When I try to run this code: Button (action: {paper.isSelected.toggle()}) The error is coming from the 'toggle()' member, but the value I am trying to toggle (isSelected) is a variable, not a constant, so I...
$usd_cny) } } } mutating func update(_ price: String) { self.usd_cny = price }}@propertyWrapperstruct Converter { var from: String var to: String var rate: Double var value: Double var wrappedValue: String { get { "\(from)\(value)"} set { value = Double(newValue) ?? -1} }...
//2 Cannot assign to property: 'self' is immutable self.anotherFlag =true //3 Cannot use mutating member on immutable value: 'self' is immutable changeAnotherFlag(true) }) { Text("Test") } } } flag是标记为State的变量,anotherFlag是没有使用属性包装器的普通变量,同时增加了一个mutating的方...
我是在做数组append的时候报的错,这个时候说成员不可变,但我的成员是 var 修饰的。 那么解决方案:如果是在函数中操作, mutating func 修饰一下函数。对数...
Cannot use mutating member on immutable value: function call returns immutable value 某次事件之后,该简书的所有文章都搬到了我自己的网站 我的GitHub Cannot use mutating member on immutable value: function call returns immutable value