Question

我正处于开发应用程序的后期阶段，该应用程序需要在第一次运行时从文本文件导入大量数据库。

我的问题是，在进行大量导入时，使用进度对话框显示的最佳方法是什么。负责的代码部分如下所示（该类的构造函数）。

public ManipulateDatabase(Activity contextIn) throws IOException {
        baseHelper = new DatabaseHelper(contextIn);
        context = contextIn;
        BufferedReader pieceScan = new BufferedReader(new InputStreamReader(
                getPieceTextFile(context), "UTF-8"));
        BufferedReader specificScan = new BufferedReader(new InputStreamReader(
                getSpecificTextFile(context), "UTF-8"));
        BufferedReader elementScan = new BufferedReader(new InputStreamReader(
                getElementTextFile(context), "UTF-8"));
        BufferedReader quoteScan = new BufferedReader(new InputStreamReader(
                getQuoteTextFile(context), "UTF-8"));
        openSesame();
        String line;
        String pieceName;
        String isDrama;
        String point;
        String element;
        String quote;
        String isCharacter;
        int commaPoint;
        int commaPoint2;

        if (initialLaunch) {

            System.out.println("INITIAL LAUNCH BLOCK INITIATED");
            while ((line = pieceScan.readLine()) != null) {
                System.out.println("PieceInsertion: ");
                commaPoint = line.indexOf(",");
                pieceName = line.substring(0, commaPoint);
                isDrama = line.substring(commaPoint + 1, commaPoint + 2);
                ContentValues pv = new ContentValues();
                pv.put(pieceField, pieceName);
                pv.put(typeField, (Integer.parseInt(isDrama)));
                dataBase.insert(pieceTable, null, pv);
                System.out.println(line
                        + ": INSERTION SHOULD HAVE JUST FINISHED");
            }

            while ((line = specificScan.readLine()) != null) {
                System.out.println("SpecificInsertion: ");
                commaPoint = line.indexOf(",");
                point = line.substring(0, commaPoint);
                commaPoint2 = (line
                        .substring(commaPoint + 1, line.length() - 1)
                        .indexOf(","))
                        + point.length();
                // pieceName = line.substring(commaPoint + 1, commaPoint2 + 1);
                element = line.substring(commaPoint2 + 2, line.length());

                ContentValues sv = new ContentValues();
                sv.put(pointField, point);
                // sv.put(pieceField, pieceName);
                sv.put(elementField, element);
                dataBase.insert(specificTable, null, sv);
                System.out.println(line
                        + ": INSERTION SHOULD HAVE JUST FINISHED");
            }

            while ((line = elementScan.readLine()) != null) {
                commaPoint = line.indexOf(",");
                element = line.substring(0, commaPoint);
                commaPoint2 = (line
                        .substring(commaPoint + 1, line.length() - 1)
                        .indexOf(","))
                        + element.length();

                pieceName = line.substring(commaPoint + 1, commaPoint2 + 1);
                isCharacter = line.substring(commaPoint2 + 2, commaPoint2 + 3);

                ContentValues ev = new ContentValues();
                ev.put(elementField, element);
                ev.put(pieceField, pieceName);
                ev.put(elTypeField, (Integer.parseInt(isCharacter)));
                dataBase.insert(elementTable, null, ev);
                System.out.println(line
                        + ": INSERTION SHOULD HAVE JUST FINISHED");

            }

            while ((line = quoteScan.readLine()) != null) {
                commaPoint = line.indexOf("^");
                quote = line.substring(0, commaPoint);
                System.out.println("Quote = " + quote);
                point = line.substring(commaPoint + 1, line.length());
                System.out.println("Point = " + point);

                ContentValues qv = new ContentValues();
                qv.put(quoteField, quote);
                qv.put(pointField, point);
                dataBase.insert(quoteTable, null, qv);
                System.out.println(line
                        + ": INSERTION SHOULD HAVE JUST FINISHED");
            }

        }

    }

Answer 1

您应该使用异步任务来执行数据库加载。

http://developer.android.com/reference/android/os/AsyncTask.html

在onPreExecute（）中，您可以显示进度对话框，在onPostExecute（）中，您应该删除ProgressDialog。数据库加载应该在doInBackground（）中完成。

有很多例子。点击此处了解更多信息

How to use AsyncTask correctly in Android

你的整个ManipulateDatabase（）应该进入doInBackground（）。

Android：具有初始数据库导入的进度对话框

1 个答案: