安卓：与进度对话框重DB操作 [英] Android: Heavy DB operations with progress dialog

问题描述

我已经习惯了<一href="http://developer.android.com/reference/android/database/sqlite/SQLiteDatabase.html#beginTransaction%28%29"相对=nofollow>下面上的AsyncTask的 doInBackground 方法快速插入到数据库成语：

I have used to following idiom on the doInBackground method of an AsyncTask for quick inserts into the DB:

    mDatabase.beginTransaction();
    try {
            //... do DB stuff

            mDatabase.setTransactionSuccessful();
    } finally {
            mDatabase.endTransaction();
    }

但是，如果我用这个成语，不显示我的进度对话框（放在在preExecute 法）。在另一方面，如果我替换上面的code与普通mDatabase.execSQL（）语句，并得到显示进度对话框，但插入变得很慢。有什么办法，我可以有两全其美（即进度对话框，快速插入）的。谢谢！

However, if I use this idiom, my progress dialog (placed in the onPreExecute method) is not displayed. On the other hand, if I replace the above code with regular mDatabase.execSQL() statements, the progress dialog does get displayed but inserts become very slow. Is there any way I can have the best of both worlds (i.e., progress dialog and fast insertions). Thanks!

注：调用BeginTransaction EXCLUSIVE模式运行（我不明白这是什么意思TBH）。这是什么原因？

Note: beginTransaction run in EXCLUSIVE mode (I don't get what that means tbh). Is this the cause?

推荐答案

我找到了答案。显然，这是我doInBackground这是问题之前在做什么。我已经定义了以下内容：

I found the answer. Apparently, it was what I was doing before doInBackground which was the problem. I had defined the following:

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        mProgD = ProgressDialog.show(mContext, "", "Wait", true);
        ih = new InsertHelper(mDatabase, "dictionary");
        wordColumn = ih.getColumnIndex("word");
    }

如果我将低于ProgressDialog.show的code到doInBackground的的BeginTransaction成语前，然后获取所示的对话框。我还是不明白为什么出现这种情况，但它就在那里。感谢您的帮助。

If I move the code below ProgressDialog.show into doInBackground before the beginTransaction idiom, then the dialog gets shown. I still don't get why this happens but there it is. Thanks for all your help.

这篇关于安卓：与进度对话框重DB操作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IT屋！