将 MotionEvent ActionDown 坐标传递给内部 class (AsyncTask)

Question

正如标题所说，我希望能够将 ACTION_DOWN 上给出的坐标传递给我的 AsyncTask 内部 class 的 onPostExecute 方法。在过去的两天里，我一直在尝试这样做，但没有成功。我该怎么做？感谢您的帮助:)

这是我的代码：

package io.music.ui.settings;

import android.app.ProgressDialog;
import android.content.Intent;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.os.SystemClock;
import android.support.annotation.Nullable;

import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;


import io.music.R;
import io.music.ui.base.BaseFragment;
import io.music.ui.main.MainActivity;

import android.view.MotionEvent;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;

import com.android.volley.RequestQueue;
import com.android.volley.toolbox.JsonArrayRequest;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

import static android.R.attr.x;


public class SettingsFragment extends BaseFragment {

    public static final int CONNECTION_TIMEOUT = 10000;
    public static final int READ_TIMEOUT = 15000;
    private RecyclerView mRVFishPrice;
    private AdapterFish mAdapter;
    public float x = 0.95f;
    //String xx = String.format("%.2f", x);
    public float y = 0;
    float x1, x2, y1, y2;

    List<DataFish> data=new ArrayList<>();
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {

        final View view = inflater.inflate(R.layout.fragment_settings, container, false);

        view.setOnTouchListener(new View.OnTouchListener() {
            public boolean onTouch(View v, MotionEvent event) {

                int action = event.getAction();
                if (action == MotionEvent.ACTION_DOWN) {

                    x = 2f * (event.getX() / v.getWidth()) - 1f;
                    y = -2f * (event.getY() / v.getHeight()) + 1f;

                    //x1 = x - 0.1f;
                    //x2 = x + 0.1f;
                    //y1 = y - 0.1f;
                    //y2 = y + 0.1f;
                    TextView textView = (TextView) getView().findViewById(R.id.textView2);
                    textView.setText(String.format("%.2f", x));
                    TextView textView2 = (TextView) getView().findViewById(R.id.textView3);
                    textView2.setText(String.format("%.2f", y));
                }

                mRVFishPrice = (RecyclerView) view.findViewById(R.id.fishPriceList);
                mAdapter = new AdapterFish(getActivity(), data);
                mRVFishPrice.setAdapter(mAdapter);
                mRVFishPrice.setLayoutManager(new LinearLayoutManager(getActivity()));

                return false;
            }

        });


        new AsyncFetch().execute();

        return view;
    }




    private class AsyncFetch extends AsyncTask<String, String, String> {
        ProgressDialog pdLoading = new ProgressDialog(getActivity());
        HttpURLConnection conn;
        URL url = null;

        @Override
        protected void onPreExecute() {
            super.onPreExecute();

            //this method will be running on UI thread
            pdLoading.setMessage("\tLoading...");
            pdLoading.setCancelable(false);
            pdLoading.show();

        }

        @Override
        protected String doInBackground(String... params) {
            try {

                // Enter URL address where your json file resides
                // Even you can make call to php file which returns json data
                url = new URL("http://example.com/Subjects2.php");

            } catch (MalformedURLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                return e.toString();
            }
            try {

                // Setup HttpURLConnection class to send and receive data from php and mysql
                conn = (HttpURLConnection) url.openConnection();
                conn.setReadTimeout(READ_TIMEOUT);
                conn.setConnectTimeout(CONNECTION_TIMEOUT);
                conn.setRequestMethod("POST");

                // setDoOutput to true as we recieve data from json file

                conn.setDoOutput(true);


            } catch (IOException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
                return e1.toString();
            }

            try {

                int response_code = conn.getResponseCode();

                // Check if successful connection made
                if (response_code == HttpURLConnection.HTTP_OK) {

                    // Read data sent from server
                    InputStream input = conn.getInputStream();
                    BufferedReader reader = new BufferedReader(new InputStreamReader(input));
                    StringBuilder result = new StringBuilder();
                    String line;

                    while ((line = reader.readLine()) != null) {
                        result.append(line);
                    }

                    // Pass data to onPostExecute method
                    return (result.toString());

                } else {

                    return ("unsuccessful");
                }

            } catch (IOException e) {
                e.printStackTrace();
                return e.toString();
            } finally {
                conn.disconnect();
            }


        }


        @Override
        public void onPostExecute(String result) {

            //this method will be running on UI thread


            pdLoading.dismiss();


            pdLoading.dismiss();
            try {

                JSONArray jArray = new JSONArray(result);

                // Extract data from json and store into ArrayList as class objects
                for(int i=0;i<jArray.length();i++){

                    JSONObject json_data = jArray.getJSONObject(i);

                    String xx= String.format("%.2f", x);
                    if(json_data.getString("X").equals(xx) ) {
                        DataFish fishData = new DataFish();

                        fishData.fishName = json_data.getString("SongName");
                        fishData.catName = json_data.getString("X");
                        fishData.sizeName = json_data.getString("Y");

                        data.add(fishData);

                    }
                }

                // Setup and Handover data to recyclerview


            } catch (JSONException e) {
                Toast.makeText(getActivity(), e.toString(), Toast.LENGTH_LONG).show();
            }

        }

    }


}

编辑：我还想说明我正在尝试将变量 x 和 y 获取到 onPostExecute 方法，并且我已经为 x 只是为了测试 json 输出是否正确。我希望 x 坐标来自 TouchListener.

Answer 1

你确实应该只加载一次 json 文件，当 activity/fragment 加载时，但你可能希望在文件加载且片段尚未准备好时显示一些进度条接受用户触摸。（参见 this）

文件下载完成后，您进入 onPostExecute:

将 jArray 更改为 class 字段，并将 new JSONArray(result); 存储在其中，以便可以从 class.
隐藏进度条，向用户显示真实布局。

然后在您的 onTouch 实现中，使用 jArray 中的值执行填充 RecyclerView 的 for 循环（将该代码从 onPostExecute 移动到 onTouch听众）

将 MotionEvent ActionDown 坐标传递给内部 class (AsyncTask)

Pass MotionEvent ActionDown coordinates to inner class (AsyncTask)

android

json

android-asynctask

coordinates

motionevent