Cards将不会填充来自TMDB API的电影名称

Question

我正在为一个项目创建一个应用程序，您可以通过电影名称和图像滑动，现在我只是想让名称工作，但我的卡片不会填充电影名称。我有一些麻烦与阵列适配器，但我认为它现在工作在正确的地方。我正在使用github的卡片库，它适用于其他程序，只是无法让它与此一起工作。也许是因为模特课?只是失去的时候没有真正的错误。Item.xml是带有文本和背景的卡片的设计，而activity_main.xml是我引用库的地方。Hellotext是item.xml中的textview。任何帮助都是感激的!

public class MainActivity extends AppCompatActivity {
private ArrayList<String> al;
private ArrayAdapter<MovieModelClass> arrayAdapter;
private ArrayList<MovieModelClass> movieList = new ArrayList<>();
private int i;
String moviename;

private static String JSON_URL = "https://api.themoviedb.org/3/movie/popular?api_key=8099f5720bad1f61f020fdbc855f73db";
//List<MovieModelClass> movieList;
//@InjectView(R.id.frame) SwipeFlingAdapterView flingContainer;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
GetData getData = new GetData();
getData.execute();


//AddArray();
// ButterKnife.inject(this);
//this add is the name of the card, with each add another card is added
//adds into array
//the array has a text and a layout we create
//this layout is the card in itself textview picture ect...

//this is when it actually swipes(clicks and movies)
SwipeFlingAdapterView flingContainer = (SwipeFlingAdapterView) findViewById(R.id.frame);
flingContainer.setAdapter(arrayAdapter);
flingContainer.setFlingListener(new SwipeFlingAdapterView.onFlingListener() {
//every time a card is completely removed he just removes it from the array
//notifies the adapter of this change
@Override
public void removeFirstObjectInAdapter() {
// this is the simplest way to delete an object from the Adapter (/AdapterView)
Log.d("LIST", "removed object!");
movieList.remove(0);
arrayAdapter.notifyDataSetChanged();
}
@Override
public void onLeftCardExit(Object dataObject) {
//Do something on the left!
//You also have access to the original object.
//If you want to use it just cast it (String) dataObject
Toast.makeText(MainActivity.this, "left", Toast.LENGTH_SHORT).show();
}
@Override
public void onRightCardExit(Object dataObject) {
Toast.makeText(MainActivity.this, "right", Toast.LENGTH_SHORT).show();
}
@Override
public void onAdapterAboutToEmpty(int itemsInAdapter) {
// Ask for more data here
// movieList.add();
//   arrayAdapter.notifyDataSetChanged();
//   Log.d("LIST", "notified");
//  i++;
}
@Override
public void onScroll(float scrollProgressPercent) {
/* View view = flingContainer.getSelectedView();
view.findViewById(R.id.item_swipe_right_indicator).setAlpha(scrollProgressPercent < 0 ? -scrollProgressPercent : 0);
view.findViewById(R.id.item_swipe_left_indicator).setAlpha(scrollProgressPercent > 0 ? scrollProgressPercent : 0);*/
}

});

// Optionally add an OnItemClickListener
flingContainer.setOnItemClickListener(new SwipeFlingAdapterView.OnItemClickListener() {
@Override
public void onItemClicked(int itemPosition, Object dataObject) {
Toast.makeText(MainActivity.this, "click", Toast.LENGTH_SHORT).show();
}
});
}

Api(相同的类)

public class GetData extends AsyncTask<String, String, String> {
@Override
protected String doInBackground(String... strings) {
String current = "";
try {
URL url;
HttpURLConnection urlConnection = null;
try {
url = new URL(JSON_URL);
urlConnection = (HttpURLConnection) url.openConnection();
InputStream is = urlConnection.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
int data = isr.read();
while (data != -1) {
current += (char) data;
data = isr.read();
}
return current;
} catch (MalformedURLException e) {
e.printStackTrace();;
} catch (IOException e) {
e.printStackTrace();
} finally {
if (urlConnection != null) {
//  urlConnection.disconnect();
}
}
} catch (Exception e) {
e.printStackTrace();
}

return current;
}
@Override
protected void onPostExecute(@org.jetbrains.annotations.NotNull String s){
try{
JSONObject jsonObject = new JSONObject(s);
JSONArray jsonArray = jsonObject.getJSONArray("results");
for(int i = 0; i< jsonArray.length(); i++){
JSONObject jsonObject1 = jsonArray.getJSONObject(i);

MovieModelClass model = new MovieModelClass();
//  model.setId(jsonObject1.getString("vote_average"));
model.setName(jsonObject1.getString("title"));
//  model.setImg(jsonObject1.getString("poster_path"));

moviename = jsonObject1.getString("title");
model.setName(moviename);

movieList = new ArrayList<>();
movieList.add(model);
arrayAdapter = new ArrayAdapter<>(getApplicationContext(), R.layout.item, R.id.helloText, movieList);

}

} catch (JSONException e) {
e.printStackTrace();
}
}
}

更新* * *

我修复了null问题，但我的卡现在填充我的项目名称，所以我只看到一张卡与com.project300.populateswipecards…任何帮助吗?

private ArrayList<String> al;
private ArrayAdapter<MovieModelClass> arrayAdapter;
private ArrayList<MovieModelClass> movieList = new ArrayList<>();
private int i;
String moviename = "";
Context context;
SwipeFlingAdapterView flingContainer;

private static String JSON_URL = "https://api.themoviedb.org/3/movie/popular?api_key=8099f5720bad1f61f020fdbc855f73db";
//List<MovieModelClass> movieList;
//@InjectView(R.id.frame) SwipeFlingAdapterView flingContainer;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
flingContainer = (SwipeFlingAdapterView) findViewById(R.id.frame);

GetData getData = new GetData();
getData.execute();


//AddArray();
// ButterKnife.inject(this);
//this add is the name of the card, with each add another card is added
//adds into array
//the array has a text and a layout we create
//this layout is the card in itself textview picture ect...

//this is when it actually swipes(clicks and movies)

flingContainer.setFlingListener(new SwipeFlingAdapterView.onFlingListener() {

//every time a card is completely removed he just removes it from the array
//notifies the adapter of this change
@Override
public void removeFirstObjectInAdapter() {
// this is the simplest way to delete an object from the Adapter (/AdapterView)
//  Log.d("LIST", "removed object!");
//  movieList.remove(0);
//  arrayAdapter.notifyDataSetChanged();
}
@Override
public void onLeftCardExit(Object dataObject) {
//Do something on the left!
//You also have access to the original object.
//If you want to use it just cast it (String) dataObject
Toast.makeText(MainActivity.this, "left", Toast.LENGTH_SHORT).show();
}
@Override
public void onRightCardExit(Object dataObject) {
Toast.makeText(MainActivity.this, "right", Toast.LENGTH_SHORT).show();
}
@Override
public void onAdapterAboutToEmpty(int itemsInAdapter) {
// Ask for more data here
// movieList.add();
//   arrayAdapter.notifyDataSetChanged();
//   Log.d("LIST", "notified");
//  i++;
}
@Override
public void onScroll(float scrollProgressPercent) {
/* View view = flingContainer.getSelectedView();
view.findViewById(R.id.item_swipe_right_indicator).setAlpha(scrollProgressPercent < 0 ? -scrollProgressPercent : 0);
view.findViewById(R.id.item_swipe_left_indicator).setAlpha(scrollProgressPercent > 0 ? scrollProgressPercent : 0);*/
}

});

// Optionally add an OnItemClickListener
flingContainer.setOnItemClickListener(new SwipeFlingAdapterView.OnItemClickListener() {
@Override
public void onItemClicked(int itemPosition, Object dataObject) {
Toast.makeText(MainActivity.this, "click", Toast.LENGTH_SHORT).show();
}
});

}
public class GetData extends AsyncTask<String, String, String> {
@Override
protected String doInBackground(String... strings) {
String current = "";
try {
URL url;
HttpURLConnection urlConnection = null;
try {
url = new URL(JSON_URL);
urlConnection = (HttpURLConnection) url.openConnection();
InputStream is = urlConnection.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
int data = isr.read();
while (data != -1) {
current += (char) data;
data = isr.read();
}
return current;
} catch (MalformedURLException e) {
e.printStackTrace();;
} catch (IOException e) {
e.printStackTrace();
} finally {
if (urlConnection != null) {
//  urlConnection.disconnect();
}
}
} catch (Exception e) {
e.printStackTrace();
}

return current;
}
@Override
protected void onPostExecute(@org.jetbrains.annotations.NotNull String s){

try{
JSONObject jsonObject = new JSONObject(s);
JSONArray jsonArray = jsonObject.getJSONArray("results");
for(int i = 0; i< jsonArray.length(); i++) {
JSONObject jsonObject1 = jsonArray.getJSONObject(i);

MovieModelClass model = new MovieModelClass();
movieList = new ArrayList<>();
//  model.setId(jsonObject1.getString("vote_average"));
//   model.setName(jsonObject1.getString("title"));
//  model.setImg(jsonObject1.getString("poster_path"));

moviename = jsonObject1.getString("title");
model.setName(moviename);
movieList.add(model);

arrayAdapter = new ArrayAdapter<>(MainActivity.this, R.layout.item, R.id.helloText, movieList);
flingContainer.setAdapter(arrayAdapter);
arrayAdapter.notifyDataSetChanged();

}

} catch (JSONException e) {
e.printStackTrace();
}


}
}

Answer 1

在onPostExecute()方法的末尾，我看到如下:

arrayAdapter = new ArrayAdapter<>(getApplicationContext(), R.layout.item, R.id.helloText, movieList);

我想你认为这会更新卡片列表，因为在onCreate()的早些时候你已经这样写了:

flingContainer.setAdapter(arrayAdapter);

然而，这不是new关键字和Java对象引用的工作方式。这两个适配器是完全独立的，flingContainer不"看到"。在任务中创建的适配器。

解决这个问题的最简单的方法可能是在创建适配器后重新设置适配器。

arrayAdapter = new ArrayAdapter<>(getApplicationContext(), R.layout.item, R.id.helloText, movieList);
flingContainer.setAdapter(arrayAdapter);

---

现在的问题似乎是这个for循环:

for(int i = 0; i< jsonArray.length(); i++) {
// ...
movieList = new ArrayList<>();
// ...
movieList.add(model);    
arrayAdapter = new ArrayAdapter<>(MainActivity.this, R.layout.item, R.id.helloText, movieList);
flingContainer.setAdapter(arrayAdapter);
arrayAdapter.notifyDataSetChanged();
}

您需要将ArrayList创建和适配器逻辑移出循环。

movieList = new ArrayList<>();
for(int i = 0; i< jsonArray.length(); i++) {
// ...
movieList.add(model);  
}
arrayAdapter = new ArrayAdapter<>(MainActivity.this, R.layout.item, R.id.helloText, movieList);
flingContainer.setAdapter(arrayAdapter);