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公共建筑Kotlin

constructor kotlin android

-1

Tony · 技术社区 · 6 年前

在活动A中,我有这个

 override fun onTabSelected(p0: TabLayout.Tab?) {
                val position = p0?.position
                when (position) {
                    0 ->
                        supportFragmentManager.beginTransaction().replace(
                            R.id.frame_container,
                            CallFragment(mWorkOrder.title,mWorkOrder.description,mWorkOrder.location.name,mWorkOrder.status)
                        ).addToBackStack(null).commit()
                }
            }

在片段中

class CallFragment : BaseFragment() {


    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        val view = inflater.inflate(R.layout.fragment_create, container, false)
        return view
    }


    class CallFragment(mTitle: String, mDescription: String, mLocation: String, mStatus: String) {

        var title: String
        var description: String
        var location: String
        var status: String

        init {
            title = mTitle
            description = mDescription
            location = mLocation
            status = mStatus    
        }
    }

活动A中的错误

Too many arguments for public constructor CallFragment() defined in xxx

我在callFragment中用相同数量的参数定义了一个新的构造函数,但该方法似乎没有被调用。任何帮助都将不胜感激。

1 回复 | 直到 6 年前

Son Truong 6 年前

在Android中,如果要将参数传递给片段类,建议使用工厂方法。

class CallFragment : BaseFragment() {

    override fun onCreateView(
            inflater: LayoutInflater, container: ViewGroup?,
            savedInstanceState: Bundle?
    ): View? {
        val view = inflater.inflate(R.layout.fragment_create, container, false)
        // Get arguments' value
        val title = arguments!!.getString(ARGUMENT_TITLE)
        val description = arguments!!.getString(ARGUMENT_DESCRIPTION)
        val location = arguments!!.getString(ARGUMENT_LOCATION)
        val status = arguments!!.getString(ARGUMENT_STATUS)
        return view
    }

    companion object {
        private const val ARGUMENT_TITLE = "ARGUMENT_TITLE"
        private const val ARGUMENT_DESCRIPTION = "ARGUMENT_DESCRIPTION"
        private const val ARGUMENT_LOCATION = "ARGUMENT_LOCATION"
        private const val ARGUMENT_STATUS = "ARGUMENT_STATUS"

        /**
         * Using this factory method to create an instance of this fragment based on given arguments.
         */
        fun newInstance(title: String, description: String, location: String, status: String): CallFragment {
            return CallFragment().apply {
                val args = Bundle().apply {
                    putString(ARGUMENT_TITLE, title)
                    putString(ARGUMENT_DESCRIPTION, description)
                    putString(ARGUMENT_LOCATION, location)
                    putString(ARGUMENT_STATUS, status)
                }
                arguments = args
            }
        }
    }
}

在活动中使用下面的片段

override fun onTabSelected(p0: TabLayout.Tab?) {
                val position = p0?.position
                when (position) {
                    0 ->
                        supportFragmentManager.beginTransaction().replace(
                            R.id.frame_container,
                            CallFragment.newInstance(mWorkOrder.title,mWorkOrder.description,mWorkOrder.location.name,mWorkOrder.status)
                        ).addToBackStack(null).commit()
                }
            }