kotlin.UninitializedPropertyAccessException: lateinit 属性 首选项尚未初始化

Question

我在我的多个项目中使用了共享首选项的代码并且它工作正常但是现在当我在另一个项目中应用相同的代码时它停止工作。以下是错误

kotlin.UninitializedPropertyAccessException: lateinit property preferences has not been initialized

共享首选项代码

object AppPrefrence {
    private const val NAME = "AComputerEngineer"
    private const val MODE = Context.MODE_PRIVATE
    private lateinit var preferences: SharedPreferences

    private val user_id = Pair("user_id","")
    private val ngo_id = Pair("ngo_id","")
    private val IS_LOGIN = Pair("is_login", false)
    private val catagoryName = Pair("Catagory", "")
    private val user_phone = Pair("user_phone", "")


    fun init(context: Context) {
        preferences = context.getSharedPreferences(NAME, MODE)
    }
    //an inline function to put variable and save it
    private inline fun SharedPreferences.edit(operation: (SharedPreferences.Editor) -> Unit) {
        val editor = edit()
        operation(editor)
        editor.apply()
    }
    var userId: String
        get() = preferences.getString(user_id.first, user_id.second) ?: ""
        set(value) = preferences.edit {
            it.putString(user_id.first, value)
        }

    var ngoId: String
        get() = preferences.getString(ngo_id.first, ngo_id.second) ?: ""
        set(value) = preferences.edit {
            it.putString(ngo_id.first, value)
        }
    //SharedPreferences variables getters/setters
    var isLogin: Boolean
        get() = preferences.getBoolean(IS_LOGIN.first, IS_LOGIN.second)
        set(value) = preferences.edit {
            it.putBoolean(IS_LOGIN.first, value)
        }

    var category: String
        get() = preferences.getString(catagoryName.first, catagoryName.second) ?: ""
        set(value) = preferences.edit {
            it.putString(catagoryName.first, value)
        }

    var userPhone:String
    get() = preferences.getString(user_phone.first, user_phone.second)?:""
    set(value) = preferences.edit{
        it.putString(user_phone.first,value)
    }
}

在变量中设置值

   imgBtn_food?.setOnClickListener(View.OnClickListener {
                var fd = "food"
                catagoryname = fd
                AppPrefrence.category = catagoryname.toString()
                startActivity(Intent(this, Food_Ngo_Activity::class.java))
            })

Answer 1

在访问 lateinit 变量之前，您应该 initialized 它。在您的情况下，可以通过调用方法 init().

来实现初始化

因此您的代码将如下所示：

AppPrefrence.init(this) // pass your context here
imgBtn_food?.setOnClickListener(View.OnClickListener {
                var fd = "food"
                catagoryname = fd
                AppPrefrence.category = catagoryname.toString()
                startActivity(Intent(this, Food_Ngo_Activity::class.java))
            })