Question

好的，我有一个自定义视图，可以从互联网上播放GIF。因此我需要在我的视图中添加一个url来下载gif。但我似乎无法在asynctask内更新自定义视图。我需要在自定义视图gifView.setUrl()中添加网址字符串。它在onCreate类中工作，但它在asynctask中给我null。

Oncreate class

    GifView gifView;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        Bundle extras = getIntent().getExtras();
        id = extras.getInt("id");
        String idStr = String.valueOf(id);

        String extension = extras.getString("extension");
        if(extension.equals(".gif")){
            setContentView(R.layout.activity_post_gif);
            Toolbar toolbar = (Toolbar)findViewById(R.id.toolbar);
            setSupportActionBar(toolbar);

            gifView = (GifView)findViewById(R.id.gifview);
            titleStr = (TextView)findViewById(R.id.titleTXT);
            postInfo = (TextView)findViewById(R.id.infoTXT);

            getSupportActionBar().setDisplayHomeAsUpEnabled(true);
            getSupportActionBar().setDisplayShowTitleEnabled(false);

//the url
            new getJsonInfoGif().execute("http://www.website.com/jsonApi");
        }else{

的AsyncTask

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

    @Override
    protected void onPreExecute() {
        progressDialog = new ProgressDialog(context);
        progressDialog.setMessage("loading post...");
        progressDialog.show();
    }

    @Override
    protected String doInBackground(String... strings) {
        return GET(strings[0]);
    }

    @Override
    protected void onPostExecute(String res) {
        try {
            JSONObject jsonObject = new JSONObject("{'postinfo':[" + res + "]}");
            JSONArray jsonArray = jsonObject.getJSONArray("postinfo");
            JSONObject obj = jsonArray.getJSONObject(0);
            //post title
            titleStr.setText(obj.getString("name"));
            //category and maker full name
            //large image
            JSONObject imgObj = obj.getJSONObject("thumbnails");
            gifView.setUrl("http://www.website.com/my.gif");

        } catch (JSONException e) {
            e.printStackTrace();
        }
        if (progressDialog != null) {
            progressDialog.dismiss();
        }
    }
}

GifView.java

public void setUrl(String urlStr){
    this.urlStr = urlStr;
    invalidate();
    requestLayout();
}

public String getUrl(){
    return this.urlStr;
}

public void init(final Context context)throws IOException{
    setFocusable(true);
    movie = null;
    movieWidth = 0;
    movieHeight = 0;
    movieDuration = 0;
    final Thread thread = new Thread(new Runnable() {
        @Override
        public void run(){
            try{
                Log.d("DEBUG", "URL" + urlStr);
                URL url = new URL(urlStr);

                try {
                    HttpURLConnection http = (HttpURLConnection) url.openConnection();
                    inputStream = http.getInputStream();

                    try {
                        Thread.sleep(3000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }

                    movie = Movie.decodeStream(inputStream);

                    movieWidth = movie.width();
                    movieHeight = movie.height();
                    movieDuration = movie.duration();

                    ((PostActivity) context).runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            invalidate();
                            requestLayout();
                        }
                    });
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    });
    thread.start();
}

这是来自url的Log，如果我在Activity中的asynctask中添加url，它会给我null。

11-07 14:41:58.821    5674-6076/svenmobile.tools.showcase D/DEBUG﹕ URLnull

我想知道的是问题是什么以及如果可能的话如何解决它。提前谢谢，斯文

Answer 1

也许您在init()之前致电setUrl()。

您可以将其传递给构造函数中的url，或public void init(final Context context, String urlStr)throws IOException{

我还建议您将所有网络代码移至doInBackground

android更新asynctask中的自定义视图

1 个答案: