如何获取动态设置为 TextView 的文本？

Question

在我的 MainActivity.java 中，我已经为 TextView 设置了一些文本，如何获取我设置到 TextView 的文本

我的文本视图 -

<TextView
android:id="@+id/show"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:visibility="visible" />

异步任务-

public class fetchdata extends AsyncTask<Void, Void, Void> {
private String data = "";

@Override
protected Void doInBackground(Void... voids) {
    try {
        URL url = new URL("https://blablabla.com/hello.json");
        HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
        InputStream inputStream = httpURLConnection.getInputStream();
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
        data = bufferedReader.readLine();
    } catch (MalformedURLException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    return null;
}
@Override
protected void onPostExecute(Void aVoid) {
    super.onPostExecute(aVoid);
   MainActivity.show.setText(this.data);
}

}

主要活动 -

private static TextView show;

......显示是静态的

show = findViewById(R.id.show);
String data = show.getText().toString();

但是数据是空的而不是我得到 "this is the text I want to get"

Answer 1

 class fetchdata extends AsyncTask<Void, Void, String> {
        private String data = "";

        @Override
        protected String doInBackground(Void... voids) {
            try {
                URL url = new URL("https://blablabla.com/hello.json");
                HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
                InputStream inputStream = httpURLConnection.getInputStream();
                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
               return data = bufferedReader.readLine();
            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return null;
        }

        @Override
        protected void onPostExecute(String aVoid) {
            super.onPostExecute(aVoid);
            show.setText(aVoid);
        }
    }

Answer 2

考虑到下面两行是在一起的，

show = findViewById(R.id.show);
String data = show.getText().toString();

我猜它们在 onCreate 中，从而导致 data.

为空

您需要等待 AsyncTask 完成并 TextView 在 onPostExecute 中设置它的值，然后再尝试在 UI 中获取它线。（你可以使用 callback）

如何获取动态设置为 TextView 的文本？

how to get the text that was set dynamically to a TextView?

java

android

textview