如何使用getCallback以外在一个getCallback提供的数据 [英] How to use data provided in a getCallback outside of the getCallback

问题描述

所以我使用的解析现在运行我的应用程序的后端。当您查询您解析数据库，数据是在一个看似不可思议的方式返回（给我，但我是新来的这一点） -

So I'm using Parse for now to run the backend of my app. When you query your Parse database, data is returned in a seemingly weird way (to me, but I'm new to this) -

            query.getFirstInBackground(new GetCallback() {
            public void done(ParseObject object, ParseException e) {
              if (object == null) {
              } else {
              }
            }
          });

和从查询的数据可用于例如Else语句内。我能做的日期时间= object.getCreatedAt（）;拿到检索对象的创建时间。

And the data from the query is available for example within the Else statement. I can do Date time = object.getCreatedAt(); to get the time the retrieved object was created at.

但是，问题来约，因为我想用这些数据来更新一个TextView的我的应用程序中的文本。我觉得像数据是卡住回调（这我知道里面很可能不是真正的我想的办法做到这一点，我得到一个错误：不能指非final的变量UPDATETEXT定义的内部类中。在不同的方法，该错误是在UPDATETEXT，timeText，表，我这里是没有相关的code片段 -

But, the problem comes about because I want to use that data to update the text of a textView within my app. I feel like the data is "stuck" inside the callBack (which I realize is probably not true. The way I'm trying to do it I get an error: "Cannot refer to a non-final variable updateText inside an inner class defined in a different method". The error is on updateText, timeText, table, and i. Here is the relevant code snippet that is failing -

TableLayout table = (TableLayout) findViewById(R.id.tableLayout);
    TextView courtText;
    TextView updateText;
    TextView timeText;
    // For each row
    for (int i = 0; i < table.getChildCount(); i++) {
        // Get the one `courtText` in this row
        courtText = (TextView) table.getChildAt(i).findViewById(R.id.courtText);

        ParseQuery query = new ParseQuery("Updates");
        query.whereEqualTo("court",courtText);
        query.orderByAscending("createdAt");
        query.getFirstInBackground(new GetCallback() {
            public void done(ParseObject object, ParseException e) {
              if (object == null) {
                Log.d("update", "The getFirst request failed.");
              } else {
                Log.d("update", "Retrieved the object.");

                String update = object.getString("update");
                Date time = object.getCreatedAt();

                updateText = (TextView) table.getChildAt(i).findViewById(R.id.updateText);
                timeText = (TextView) table.getChildAt(i).findViewById(R.id.timeText);

                updateText.setText(update);
                java.text.DateFormat dateFormat = android.text.format.DateFormat.getDateFormat(getApplicationContext());
                timeText.setText(dateFormat.format(time));
              }
            }
          });

    }

任何帮助将是AP preciated。

Any help would be appreciated.

推荐答案

我不能现在就测试，但这样的事情应该工作：

I'm not able to test it right now, but something like this should work:

final TableLayout table = (TableLayout) findViewById(R.id.tableLayout);
TextView courtText;

for (int i = 0; i < table.getChildCount(); i++) {
    courtText = (TextView) table.getChildAt(i).findViewById(R.id.courtText);
    final TextView updateText = (TextView) table.getChildAt(i).findViewById(R.id.updateText);
    final TextView timeText = (TextView) table.getChildAt(i).findViewById(R.id.timeText);

    ParseQuery query = new ParseQuery("Updates");
    query.whereEqualTo("court",courtText);
    query.orderByAscending("createdAt");
    query.getFirstInBackground(new GetCallback() {
        public void done(ParseObject object, ParseException e) {
            if (object == null) {
                Log.d("update", "The getFirst request failed.");
            } else {
                Log.d("update", "Retrieved the object.");

                String update = object.getString("update");
                Date time = object.getCreatedAt();

                updateText.setText(update);
                java.text.DateFormat dateFormat = android.text.format.DateFormat.getDateFormat(getApplicationContext());
                timeText.setText(dateFormat.format(time));
            }
        }
    });
}

此方式，从需要被从里面（ UPDATETEXT 和 timeText ）的声明最后，所以一切都应该工作。

This way the only two variables from outside the inner class that need to be accessed from inside it (updateText and timeText) are declared final, so everything should work.

这篇关于如何使用getCallback以外在一个getCallback提供的数据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！