【发布时间】：2015-10-26 04:31:35
【问题描述】：
我正在从电影数据库 API 获取数据，有时图像无法加载，有时加载缓慢。我正在将图像 url 解码为位图，然后使用适配器将它们设置为图像视图。请告诉我在哪里犯了错误。我正在从 API 获取图像 url。 MainActivity.java：
package com.example.sahilshokeen.movie;
public class MainActivity extends Activity {
private RecyclerView recyclerView;
private GridLayoutManager manager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//checking network
ConnectivityManager connMgr = (ConnectivityManager)
getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
if (networkInfo != null && networkInfo.isConnected()) {
// fetch data
new FetchData().execute();
new Convert().execute();
} else {
// display error
Toast toast = Toast.makeText(this, "No Network", Toast.LENGTH_LONG);
toast.show();
}
//setting adapter
recyclerView = (RecyclerView) findViewById(R.id.recyclers);
manager = new GridLayoutManager(MainActivity.this, 2);
recyclerView.setAdapter(new Adapter());
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(manager);
}
public class FetchData extends AsyncTask<Void, Void, Void> {
private HttpURLConnection connection = null;
private BufferedReader reader = null;
private String json;
private String urlString = "http://api.themoviedb.org/3/movie/popular?api_key=b6f6fcfbb225d8c500e4404655ccadcc&certification=G";
private String image = " http://image.tmdb.org/t/p/w92/";
@Override
protected Void doInBackground(Void... params) {
//connecting to network
try {
URL url = new URL(urlString);
connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
connection.connect();
StringBuffer buffer = new StringBuffer();
InputStream stream = connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(stream));
String line;
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
json = buffer.toString();
//getting json data
try {
JSONObject object = new JSONObject(json);
JSONArray array = object.getJSONArray("results");
for (int i = 0; i < 6; i++) {
Data.objects[i] = array.getJSONObject(i);
Data.title[i] = Data.objects[i].getString("original_title");
Data.overview[i] = Data.objects[i].getString("overview");
Data.date[i] = Data.objects[i].getString("release_date");
Data.image[i] = Data.objects[i].getString("poster_path");
Data.vote[i] = Data.objects[i].getDouble("vote_average");
Data.image[i] = image + Data.image[i];
}
} catch (JSONException e) {
e.printStackTrace();
}
} catch (Exception e) {
e.printStackTrace();
} finally {
connection.disconnect();
}
try {
if (reader != null) {
reader.close();
}
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
}
public class Convert extends AsyncTask<Void, Void, Void>{
@Override
protected Void doInBackground(Void... params) {
for(int i=0;i<6;i++) {
try {
URL url = new URL(Data.image[i]);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream input = connection.getInputStream();
Bitmap myBitmap = BitmapFactory.decodeStream(input);
Data.bImage[i] = myBitmap;
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
if (id == R.id.action_refresh) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
Adapter.java：
package com.example.sahilshokeen.movie;
public class Adapter extends RecyclerView.Adapter<Adapter.Holder> {
public static class Holder extends RecyclerView.ViewHolder {
public CardView cardView;
public ImageView imageView;
public Holder(View itemView) {
super(itemView);
cardView = (CardView) itemView.findViewById(R.id.card);
imageView = (ImageView) itemView.findViewById(R.id.images);
}
}
@Override
public Holder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.grid_item, parent, false);
Holder holder = new Holder(view);
return holder;
}
@Override
public void onBindViewHolder(Holder holder, int position) {
holder.imageView.setImageBitmap(Data.bImage[position]);
}
@Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
super.onAttachedToRecyclerView(recyclerView);
}
@Override
public int getItemCount() {
return Data.bImage.length;
}
}
Data.java：
package com.example.sahilshokeen.movie;
public class Data {
public static JSONObject[] objects = new JSONObject[6];
public static String[] title = new String[6];
public static String[] overview = new String[6];
public static String[] date = new String[6];
public static String[] image = new String[6];
public static Bitmap[] bImage = new Bitmap[6];
public static Double[] vote = new Double[6];
}
【问题讨论】：
-
刚刚检查了你的一张图片image.tmdb.org/t/p/w92/AjbENYG3b8lhYSkdrWwlhVLRPKR.jpg，你应该考虑使用 Glide 来加载你的图片以获得更好的性能。
-
我同时使用了 picasso 和 glide，但它不起作用。然后我解码了有效的图像，但对于小尺寸图像。
-
如果你使用了两个第三方库，但都不起作用，这意味着你的代码有问题。我看到你先把它转换成位图，你不需要这样做，给我看你编辑的代码。
-
使用库的代码？
-
在我使用的 onBindViewHolder 方法中：Picasso.with(holder.imageview.getContext()).load(Data.image[position]).into(holder.imageview) 我还删除了位图的转换代码，但它仍然不起作用
标签： java android image api android-adapter