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，它正常工作，但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

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)
    }
}

   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，应该对其进行初始化。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))
            })