Question

我正在开发一个Android项目，我正在从https://www.themoviedb.org/下载信息，包括要在活动中显示的jpg文件。一切都按预期工作，除了jpg路径是空的，导致一个空白的方块而不是海报。 jpg可用时构造的url示例： http://image.tmdb.org/t/p/w185/3cvZAUVP0gjP0p54TOVXQ50fEyZ.jpg 当jpg不可用时构造的url的示例： http://image.tmdb.org/t/p/w185null

所以我想我可以简单地用我的drawable文件夹中的本地png文件替换null，但是我尝试了很多不同的方法，包括声明

if (poster.equals("http://image.tmdb.org/t/p/w185null")) {
                poster = "@drawable/noposter.png";
            }

然而在android监视器中我可以看到它被识别为字符串。我在代码部分阅读了android开发人员的访问资源，但它并未涵盖我的具体需求。

如果需要，我似乎无法显示默认图片。

非常感谢你的帮助。

下面是代码正常工作但如果没有可用的jpg则显示空白方块：

public class GetMoviesInfo extends AsyncTask<String, Void, List<Movies>> {

public InterfaceAsyncResponse delegate;
private final String LOGTAG = GetMoviesInfo.class.getSimpleName(); 
private final String API_KEY_HEX_NUM = "a valid key is here in my project";
private final String MOVIE_POSTER_BASE_URL = "http://image.tmdb.org/t/p/";
private final String CHOSEN_MOVIE_POSTER_SIZE = "w185";

public GetMoviesInfo(InterfaceAsyncResponse delegate){
    this.delegate = delegate;
}

@Override
protected List<Movies> doInBackground(String... parameters) {

    if (parameters.length == 0) {
        return null;
    }

    HttpURLConnection urlConnection = null;
    BufferedReader inputReader = null;
    String moviesStr = null;

    try {

        final String BASEURL = "http://api.themoviedb.org/3/discover/movie?";
        final String SORT_BY_KEY = "sort_by";
        final String APIKEY = "api_key";
        String sortedBy = parameters[0];

        Uri buildUri = Uri.parse(BASEURL).buildUpon()
                .appendQueryParameter(SORT_BY_KEY, sortedBy)
                .appendQueryParameter(APIKEY, API_KEY_HEX_NUM)
                .build();

        URL url = new URL(buildUri.toString());


        urlConnection = (HttpURLConnection) url.openConnection();
        urlConnection.setRequestMethod("GET");
        urlConnection.connect();


        InputStream inputStream = urlConnection.getInputStream();
        StringBuffer bufferStr = new StringBuffer();
        if (inputStream == null) {
            return null;
        }
        inputReader = new BufferedReader(new InputStreamReader(inputStream));

        String inputLine;
        while ((inputLine = inputReader.readLine()) != null) {
            bufferStr.append(inputLine + "\n");
        }

        if (bufferStr.length() == 0) {
            return null;
        }
        moviesStr = bufferStr.toString();

    } catch (IOException e) {
        Log.e(LOGTAG, "Error ", e);
        return null;
    } finally {
        if (urlConnection != null) {
            urlConnection.disconnect();
        }
        if (inputReader != null) {
            try {
                inputReader.close();
            } catch (final IOException e) {
                Log.e(LOGTAG, "Error closing stream", e);
            }
        }
    }

    try {
        return extractData(moviesStr);
    } catch (JSONException e) {
        Log.e(LOGTAG, e.getMessage(), e);
        e.printStackTrace();
    }
    return null;
}



@Override
protected void onPostExecute(List<Movies> returns) {
    if (returns != null) {

        delegate.onTaskCompleted(returns);
    }
}

private String getReleasedYear(String dateReleased){
    final SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd", Locale.US);
    final Calendar calendar = Calendar.getInstance();
    try {
        calendar.setTime(dateFormat.parse(dateReleased));
    } catch (ParseException e) {
        e.printStackTrace();
    }
    return Integer.toString(calendar.get(Calendar.YEAR));
}

private List<Movies> extractData(String moviesJsonString) throws JSONException {

    // Items being extracted
    final String MOVIES_ARRAY = "results";
    final String ORIGINAL_TITLE = "original_title";
    final String POSTER_PATH = "poster_path";
    final String OVERVIEW = "overview";
    final String VOTE_AVERAGE = "vote_average";
    final String RELEASED_DATE = "release_date";
    final String POPULARITY = "popularity";

    JSONObject moviesJson = new JSONObject(moviesJsonString);
    JSONArray moviesArray = moviesJson.getJSONArray(MOVIES_ARRAY);
    int moviesLength =  moviesArray.length();
    List<Movies> movies = new ArrayList<>();



    for(int i = 0; i < moviesLength; ++i) {

        // For each movie, the JSON object create a new movie object
        JSONObject movie = moviesArray.getJSONObject(i);
        String title = movie.getString(ORIGINAL_TITLE);
        String poster = MOVIE_POSTER_BASE_URL + CHOSEN_MOVIE_POSTER_SIZE + movie.getString(POSTER_PATH);
        Log.i("TAG","From GetMoviesInfo_extractData: "+ poster);
        String overview = movie.getString(OVERVIEW);
        String voteAverage = movie.getString(VOTE_AVERAGE);
        String releasedDate = getReleasedYear(movie.getString(RELEASED_DATE));
        String popularity = movie.getString(POPULARITY);

        movies.add(new Movies(title, poster, overview, voteAverage, releasedDate, popularity));
    }
    return movies;
}

}

Answer 1

你可以使用毕加索库来完成你的目标，使用我很简单的共享代码。有关更多信息，请使用此http://square.github.io/picasso/

> Picasso.with(context)
>     .load(url)
>     .placeholder(R.drawable.user_placeholder)
>     .error(R.drawable.user_placeholder_error)
>     .into(imageView);

Android - 如何在url image jpg不存在时显示本地默认图像？

1 个答案: