在后台获取数据并在UI中显示 [英] Fetch data in background and display in UI

问题描述

我正在使用凌空抽空，使用volley来获取数据并在用户界面中显示，因此加载数据需要花费时间.我想发生的是，我想在启动屏幕或加载屏幕期间在后台获取数据，并将其显示在用户interface中.我希望提取部分在另一个activity中完成，它应该是背景service，应该在"main activity"中调用它以填充字段.

I'm using volley to fetch data using volley and display in User Interface, and it takes time to load the data. What i want to happen is, I want to fetch the data in background during the splash screen or loading screen and display it in User interface. I want the fetching part to be done in another activity and it should be a background service and this should be called in "main activity" to populate the fields.

推荐答案

您可以尝试使用

You can try using the AsyncTask. So the process goes like that:

• 在 onPreExecute()中，您可以显示ProgresDialog或ProgresBar来可视化您的加载过程
• 在 doInBackground(Params ...)您开始加载数据
• ，并在 onPostExecute(Result)中显示您在UI中的数据并隐藏您的ProgresDialog/ProgresBar.

• In onPreExecute() you can show a ProgresDialog or a ProgresBar to visualize your loading process
• in doInBackground(Params...) you start loading your data
• and in onPostExecute(Result) you display your data in UI and hide your ProgresDialog/ProgresBar.

使用AsyncTask的示例.

这样做:

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

    @Override
    protected String doInBackground(String... params) {
        //Start loading your data 

        return "Data loaded";
    }

    @Override
    protected void onPostExecute(String result) {
       //Update your UI with data you loaded/start your activity with loaded data

    }

    @Override
    protected void onPreExecute(){     
    }

    @Override
    protected void onProgressUpdate(Void... values) {
    }
}

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