Question

我当前的项目正在从服务器下载数据，我想显示一个进度条，以便用户知道发生了什么。我有一个简单的警报对话框，我试图在为用户加载json数据时添加警报对话框。当我启动应用程序时，即使数据已经加载并且没有隐藏，警报对话框仍然停留在屏幕上。

AsyncTask代码：

  inner class Arr : AsyncTask<String, String, String>(){

        val progressDialog = AlertDialog.Builder(this@MainActivity)
        val dialogView = layoutInflater.inflate(R.layout.progress_dialog,null)
        val message = dialogView.findViewById<TextView>(R.id.message_id)
        val dialog = progressDialog.create()


        override fun onPreExecute() {
            super.onPreExecute()

            progressDialog.setMessage("loading")
            progressDialog.setCancelable(false)
            progressDialog.show()


        }

        //        for build connection
        override fun doInBackground(vararg url: String?): String{

            var text : String
            val connection = URL(url[0]).openConnection() as HttpURLConnection

            try {
                connection.connect()
                text = connection.inputStream.use { it.reader().use{reader -> reader.readText()} }


            } finally{

                connection.disconnect()

            }
            return text
        }

        override fun onPostExecute(result: String?) {

            super.onPostExecute(result)
            handleJson(result)

                dialog.dismiss()


        }

        override fun onProgressUpdate(vararg text: String?) {
                dialog.dismiss()

        }
        private fun handleJson (jsonString: String?){
            dialog.dismiss()

            val jsonObj = JSONObject(jsonString)
            val result = jsonObj.getJSONObject("result")
            val response = result.getJSONObject("response")
            val airport = response.getJSONObject("airport")
            val pluginData = airport.getJSONObject("pluginData")
            val schedule = pluginData.getJSONObject("schedule")
            val arrivals = schedule.getJSONObject("arrivals")
//        val data = arrivals.getJSONObject("data")
            val jsonArray = JSONArray(arrivals.get("data").toString())

            val list =  ArrayList<FlightShdu>()
            var x = 0
            while (x < jsonArray.length()){

                val jsonObject = jsonArray.getJSONObject(x)



                list.add(FlightShdu(

                    jsonObject.getJSONObject("flight").getJSONObject("identification").getJSONObject("number").getString("default"),
                    jsonObject.getJSONObject("flight").getJSONObject("airline").getString("name"),
                    jsonObject.getJSONObject("flight").getJSONObject("status").getString("text"),
                    jsonObject.getJSONObject("flight").getJSONObject("airline").getJSONObject("code").getString("icao"),
                   jsonObject.getJSONObject("flight").getJSONObject("time").getJSONObject("scheduled").getString("arrival")


                ))


                x++
            }
            list.forEach(::println)

            val adapter = ListAdapte(this@MainActivity,list)
            flight_arrivel_list.adapter = adapter

        }




    } //

有什么解决办法吗？

Answer 1

更改为此：

override fun onPreExecute() {
    super.onPreExecute()

    dialog.setMessage("loading")
    dialog.setCancelable(false)
    dialog.show()
}

并使用以下代码将其隐藏：

dialog.dismiss();

您必须引用AlertDialog对象，而不是AlertDialog.Builder。

Answer 2

在您的onPreExecute()

override fun onPreExecute() {
    ...
    progressDialog.show()
}

但是在onPostExecute()中，您调用了另一个对话框来关闭

override fun onPostExecute(result: String?) {
    ...
    dialog.dismiss()
}

因此您需要在progressDialog.dismiss()中致电onPostExecute()。

Answer 3

progressDialog.dismiss()而不是dialog.dismiss()

隐藏kotlin中的警报对话框

3 个答案: