java - 如何在警报对话框与我的 fragment 之间进行通信？

Question

我有一个名为 AlertDialogFragment 的类，它将用于在整个程序中需要时创建警报对话框。如果单击正按钮，创建对话框的 fragment 将调用一个函数；如果单击负按钮，则创建对话框的 fragment 将不调用任何函数。我对 Android 开发相当陌生，感谢任何提示或帮助。

这是我的 AlertDialogFragment:

class AlertDialogFragment : DialogFragment() {


    companion object {
        private val TAG = "AlertDialogFragment"


        fun newInstance(message: String, positiveBtnText: String, negativeBtnText: String): AlertDialogFragment {
            val fragment = AlertDialogFragment()
            fragment.isCancelable = false

            val args = Bundle()
            args.putString("aMessage", message)
            args.putString("aPositiveBtnText", positiveBtnText)
            args.putString("aNegativeBtnText", negativeBtnText)

            fragment.arguments = args
            return fragment
        }


    }


    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
        Log.d(TAG, "onCreateDialog called")
        super.onCreateDialog(savedInstanceState)
        return activity?.let {
            val builder = AlertDialog.Builder(it)
            builder.setMessage(arguments?.getString("aMessage"))
                    .setPositiveButton(arguments?.getString("aPositiveBtnText"), DialogInterface.OnClickListener { dialog, id ->
                        Log.d(TAG, "Yes!")
                    })
                    .setNegativeButton(arguments?.getString("aNegativeBtnText"), DialogInterface.OnClickListener { dialog, id ->
                        Log.d(TAG, "Dismiss!")
                    })

            Log.d(TAG, "onCreateDialog ending")
            builder.create()
        } ?: throw IllegalStateException("Activity can not be null")
    }


} 

这是我尝试初始化警报对话框并设置目标 fragment :

try {
            AlertDialogFragment alertDialogFragment = new AlertDialogFragment().Companion.newInstance(
                    "Would you like to continue?",
                    "Yes",
                    "Dismiss");
            alertDialogFragment.setTargetFragment(this, TARGET_FRAGMENT_REQUEST_CODE);
            alertDialogFragment.show(getActivity().getSupportFragmentManager(), "dialog");
        }catch (Exception e){
            e.printStackTrace();
        }

预先感谢您的帮助!

编辑:我使用 kotlin 作为警报对话框，初始化它的 fragment 是用 java 编写的。

Answer 1

您可以检索传入的目标 fragment 和请求代码，然后使用它来调用onActivityResult:

targetFragment?.let { fragment ->
    fragment.onActivityResult(fragment.targetRequestCode, Activity.RESULT_OK, null)
}

在你的函数中:

    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
        Log.d(TAG, "onCreateDialog called")
        super.onCreateDialog(savedInstanceState)
        return activity?.let {
            val builder = AlertDialog.Builder(it)
            builder.setMessage(arguments?.getString("aMessage"))
                    .setPositiveButton(arguments?.getString("aPositiveBtnText"), DialogInterface.OnClickListener { dialog, id ->
                        Log.d(TAG, "Yes!")
                        targetFragment?.let { fragment ->
                            fragment.onActivityResult(fragment.targetRequestCode, Activity.RESULT_OK, null)
                        }
                    })
                    .setNegativeButton(arguments?.getString("aNegativeBtnText"), DialogInterface.OnClickListener { dialog, id ->
                        Log.d(TAG, "Dismiss!")
                    })

            Log.d(TAG, "onCreateDialog ending")
            builder.create()
        } ?: throw IllegalStateException("Activity can not be null")
    }

在启动 fragment 中，您覆盖 onActivityResult 并处理返回的值。

请注意，如果重新创建 fragment ，您将必须重新分配目标 fragment 。