Android更改可见性GifTextView无法在AsyncTask类中工作，为什么？

Question

因此，在我的AsyncTask类（1，'gekozenOptochtDataParser'）中，我执行了另一个AsyncTask类（2）。在（2）我尝试使GIF可见并消失，但它不起作用。这与布局有关，因为当我在页脚，标题和'MainActivity'中放置'GifTextView'时它会起作用（页脚和标题是不同的布局），但是当我尝试在' MainActivity'布局不起作用。我需要使用“RunOnThread”声明吗？或者问题是什么？

使“GifTextView”可见并消失的代码（2）：

public class removeDialog extends AsyncTask<Void, Void, Void> {
Context c;
//ProgressDialog asyncDialog;
String page;
boolean running;
GifTextView loadingGif;

public removeDialog(GifTextView loadingGif, String page, Context c) {
    this.loadingGif = loadingGif;
    this.page = page;
    this.c = c;

    //asyncDialog = new ProgressDialog(c);
}

@Override
protected void onPreExecute() {
    loadingGif.setVisibility(View.VISIBLE);

    if (page == "algemeneVoorwaarden") {
        Intent intent = new Intent(c, algemeneVoorwaarden.class);
        c.startActivity(intent);
    }
    if (page == "contact") {
        Intent intent = new Intent(c, contactTest.class);
        c.startActivity(intent);
    }

    super.onPreExecute();
    running = true;
}

@Override
protected Void doInBackground(Void... arg0) {

    int i = 2;
    while(running){
        try {
            Thread.sleep(200);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        if(i-- == 0){
            running = false;
        }
    }

    return null;
}

@Override
protected void onPostExecute(Void result) {
    //hide the dialog
    loadingGif.setVisibility(View.GONE);

    super.onPostExecute(result);
}

}

执行类的代码（1，'gekozenOptochtDataParser'）：

  //footer en header toevoegen
  View header = View.inflate(c, R.layout.headergekozenoptocht, null);
  View footer = View.inflate(c, R.layout.footer, null);
  View gekozenOptochtLayout = View.inflate(c, R.layout.activity_gekozen_optocht, null);

        //gif image view pakken
        final GifTextView loadingGif = (GifTextView) gekozenOptochtLayout.findViewById(R.id.loading);

        voorwaarden.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                new removeDialog(loadingGif, "algemeneVoorwaarden", c).execute();
            }
        });

        contact.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                new removeDialog(loadingGif, "contact", c).execute();
            }
        });

        //header en footer toevoegen
        lv.addHeaderView(header, null, false);
        lv.addFooterView(footer, null, false);

        //adapter toevoegen
        lv.setAdapter(adapter);

'MainActivity'中的代码：

new gekozenOptochtDownloader(gekozenOptocht.this, urlAddress, lv).execute();