java - 如何在 AsyncTask 之后更改 ActionBar 颜色？

Question

在我的应用程序中，我正在附加到 WebView 的 onPageFinished 中执行 AsyncTask。这个方法看起来像这样:

@Override
public void onPageFinished(WebView myWebView, String url)
{
    new SendRequestAsyncTask().execute();

    // when a page has finished loading dismiss any progress dialog
    if (progressDialog != null && progressDialog.isShowing())
    {
        progressDialog.dismiss();
    }
}

SendRequestAsyncTask 看起来像这样:

public class SendRequestAsyncTask extends AsyncTask <Void, Void, Void> {

    @Override
    protected void onPreExecute() {
        // TODO Auto-generated method stub
        super.onPreExecute();
        //runs in ui thread
    }

    @Override
    protected Void doInBackground(Void... params) {
        // TODO Auto-generated method stub

        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost("myscript.php");

        try {
            // Add your data
            List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
            nameValuePairs.add(new BasicNameValuePair("request", "12345"));
            httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

            // Execute HTTP Post Request
            HttpResponse response = httpclient.execute(httppost);

            // writing response to log
            HttpEntity resEntity = response.getEntity();

            if (resEntity != null) {

                String responseStr = EntityUtils.toString(resEntity).trim();
                Log.v(TAG, "Response: " +  responseStr);

                String[] parts = responseStr.split(":");
                parts[1] = parts[1].replace("\"", "");
                parts[1] = parts[1].replace("}", "");

                if (parts[1].equals("01")){
                    actionBar.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#ffffff")));
                } else {
                    Log.v(TAG, "No success: " + parts[1]);
                }

            }

        } catch (ClientProtocolException e) {
            // TODO Auto-generated catch block
        } catch (IOException e) {
            // TODO Auto-generated catch block
        }

        return null;
    }

    @Override
    protected void onPostExecute(Void result) {
        // TODO Auto-generated method stub
        super.onPostExecute(result);
        //runs in ui thread you can update the layout here
    }
}

但是，这会使我的应用程序崩溃。所以我的猜测是我需要在 onPageFinished 方法中更改操作栏的颜色。但是，我真的不知道如何将变量从 AsyncTask 获取到 onPageFinished。此外，我不知道如何将颜色更改为 @color/ xml 文件中的颜色...

Answer 1

尝试这样的事情，

    public class SendRequestAsyncTask extends AsyncTask <Void, String, String> {

@Override
protected void onPreExecute() {
    // TODO Auto-generated method stub
    super.onPreExecute();
    //runs in ui thread
}

@Override
protected String doInBackground(Void... params) {
    // TODO Auto-generated method stub
    String strReturn = "";

    HttpClient httpclient = new DefaultHttpClient();
    HttpPost httppost = new HttpPost("myscript.php");

    try {
        // Add your data
        List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
        nameValuePairs.add(new BasicNameValuePair("request", "12345"));
        httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

        // Execute HTTP Post Request
        HttpResponse response = httpclient.execute(httppost);

        // writing response to log
        HttpEntity resEntity = response.getEntity();

        if (resEntity != null) {

            String responseStr = EntityUtils.toString(resEntity).trim();
            Log.v(TAG, "Response: " +  responseStr);

            String[] parts = responseStr.split(":");
            parts[1] = parts[1].replace("\"", "");
            parts[1] = parts[1].replace("}", "");

            strReturn = parts[1];
        }

    } catch (ClientProtocolException e) {
        // TODO Auto-generated catch block
    } catch (IOException e) {
        // TODO Auto-generated catch block
    }

    return strReturn;
}

@Override
protected void onPostExecute(String result) {
    // TODO Auto-generated method stub
    super.onPostExecute(result);
    //runs in ui thread you can update the layout here

    if (result.equals("01")){
        actionBar.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#ffffff")));
    } else {
        Log.v(TAG, "No success: " + parts[1]);
    }
}
}