在Kotlin中处理getter和setter时出错 [英] Getting error while dealing with getter and setter in kotlin

问题描述

我将数据类定义为:

  data class chatModel(var context:Context?) {

      var chatManger:ChatManager?=null
            //getter
        get() = chatManger
            //setter
        set(value) {
            /* execute setter logic */
            chatManger = value
        }

    }

现在我将如何访问get()和set()函数. 在Java中，我喜欢这样: //对于吸气剂

Now how will i access the get() and set() function. In java I do like that: //for getter

new chatModel().getJId()

//对于二传手

new chatModel().setJId("jid")

如@yole建议.我正在使用setter和getter作为:

As the @yole suggested. I am using setter and getter as:

//设置数据

var chatDetails:chatModel=chatModel(mApplicationContext)
 chatDetails.chatManger=chatManager

但是最终在

com.example.itstym.smackchat.Model.chatModel.setChatManger(chatModel.kt:38)

第38行指向

chatManger = value

这个.

@RobCo建议.

我将数据类定义更改为:

I have change the data class definition as:

data class chatModel(var context: Context?) {


    var chatManger:ChatManager

    get() = field
    set(value) {
        field=value
    }
}

//设置数据.

    chatModel(mApplicationContext).chatManger=chatManager

//获取不同活动中的数据

//get the data in different activity

chatModel(applicationContext).chatManger

，但必须初始化获取错误"属性.如果我将其分配为null，那么我将获得null而不是设置值.

but getting error property must be initialized. If I assigned it to null then I am getting null not the set value.

推荐答案

您可以在设置器内部调用设置器..a.k.a.无限循环:

You call the setter inside of the setter.. a.k.a. infinite loop:

    set(value) {
        /* execute setter logic */
        chatManger = value
    }

在属性获取器或设置器中，还有一个可用的附加变量:field.这表示该属性的Java 后备字段.

Inside a property getter or setter there is an additional variable available: field. This represents the java backing field of that property.

    get() = field
    set(value) {
        field = value
    }

使用常规的var属性，可以自动生成这些getter和setter. 因此，这是默认行为，如果您所做的只是将值设置为字段，则不必覆盖getter/setter.

With a regular var property, these getters and setters are auto-generated. So, this is default behaviour and you don't have to override getter / setter if all you do is set the value to a field.

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