问题描述

我正在尝试遍历表中的一些记录，并为每条记录使用一个值作为参数；

I am trying to loop through some records in my table and for each record, use a value as a parameter to;

1. 获取一个网页来解析一些 html
2. 获取一些要解析的 JSON 数据并从中获取几个值

这些都可以自己完美地工作，但我无法让它们都在 AsyncTask 中工作.我这里有代码.我知道我可能离题很远，但如果有人能告诉我我的想法是怎样的，我会非常感激.

These both worked perfectly by themselves, but I can not get them both working in an AsyncTask. I have the code here. I know I am probably way off, but if someone could give me a nudge into how my thinking is off, I'd really appreciate it.

第一行

    private class FetchWebsiteData extends AsyncTask<Void, String, Void> {

我明白了

Class FetchWebsiteData must either be declared abstract or implement abstract method doInBackground(params...) in 'AsynTask' 

作为错误消息并以红色下划线表示.

As an error message and underlined in red.

private class FetchWebsiteData extends AsyncTask<Void, String, Void> {


    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        mProgressDialog = new ProgressDialog(summary.this);
        mProgressDialog.setMessage("Loading...");
        mProgressDialog.setIndeterminate(false);
        mProgressDialog.show();
    }


    protected String doInBackground(String urls3, String result3) {

        helper = new TaskDBHelper(summary.this);
        SQLiteDatabase sqlDB = helper.getReadableDatabase();

        Cursor dataCount = sqlDB.rawQuery("select TASK from " + TaskContract.TABLE, null);
        ArrayList<String> temp = new ArrayList<String>();
        dataCount.moveToFirst();
        do {
            temp.add(dataCount.getString(0));
        } while (dataCount.moveToNext());
        dataCount.close();
        StringBuilder sb = new StringBuilder();
        for (String s : temp)
        {
            wallBal = s;

            //--------------------------------------------

            try {
                Document document = Jsoup.connect(URL+wallBal).get();
                Document doc = Jsoup.parse(document.text());
                balance = new Double(doc.text());
                helper = new TaskDBHelper(summary.this);
                SQLiteDatabase sqlDB2 = helper.getWritableDatabase();


                String sql9 = String.format("UPDATE " + TaskContract.TABLE + " SET " + TaskContract.Columns.OLDBAL + " = " + TaskContract.TABLE + "." + TaskContract.Columns.BAL + " WHERE task='" + wallBal + "'");
                sqlDB2.execSQL(sql9);

                String sql = String.format("UPDATE " + TaskContract.TABLE + " SET " + TaskContract.Columns.BAL + " = " + balance + " WHERE task='" + wallBal + "'");
                sqlDB2.execSQL(sql);
                Cursor dataCount2 = sqlDB.rawQuery("select " + TaskContract.Columns.OLDBAL + " from " + TaskContract.TABLE + " WHERE " + TaskContract.Columns.TASK + " = '" + wallBal + "'", null);

                dataCount2.moveToFirst();
                oldbalance = dataCount2.getDouble(0);

                if(balance != oldbalance) {
                    make();
                }
                mProgressDialog.dismiss();
                JSONObject json3 = new JSONObject(result3);
                String str = "";
                JSONArray articles3 = json3.getJSONArray("data");

                str += "articles length = "+json3.getJSONArray("data").length();
                str += "
--------
";
                str += "names: "+articles3.getJSONObject(0).getString("MasternodeIP");
                str += "
--------
";


                MNIP = articles3.getJSONObject(0).getString("MasternodeIP");
                Sts = articles3.getJSONObject(0).getString("ActiveCount");

                helper = new TaskDBHelper(summary.this);
                SQLiteDatabase sqlDB22 = helper.getWritableDatabase();

                String sql91 = String.format("UPDATE " + TaskContract.TABLE + " SET " + TaskContract.Columns.IP + " = '" + MNIP + "' WHERE task='" + task + "'");
                sqlDB22.execSQL(sql91);

                String sql10 = String.format("UPDATE " + TaskContract.TABLE + " SET " + TaskContract.Columns.STATUS + " = '" + Sts + "' WHERE task='" + task + "'");
                sqlDB22.execSQL(sql10);


                updateUI();


            } catch (JSONException | IOException e) {
                e.printStackTrace();
            }
            //-----------------------------------------------------
        }


        //--------------------------------------------------------------------







        //return null;
        return GET(urls3);
    }

    protected void onPostExecute(Void result) {

        updateUI();

    }
}

推荐答案

改变这个

protected String doInBackground(String urls3, String result3)

到

protected String doInBackground(String... args)

然后在 doInBackground 函数中像这样声明变量

Then declare your variables like so inside your doInBackground function

String urls3 = args[0];
String result3 = args[1];

您还需要将 onPostExecute 更正为

You will also need to correct your onPostExecute to

protected void onPostExecute(String result)

和你的类声明

private class FetchWebsiteData extends AsyncTask<String, Void, String>

这篇关于循环 AsyncTask 类必须声明为抽象或实现抽象方法的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持编程学习网！