有没有办法让我的应用加载屏幕上可见的所有图片，而不必旋转设备或滑动？我注意到它适用于某些尺寸而不适用于其他尺寸（但我现在需要更大的尺寸）。此外，如果我没有两组占位符图像（不知道为什么），应用程序不起作用。提前谢谢！
这是我的图像适配器：
res.render('users', {users: users})
这是我的片段：
package tk.talcharnes.popularmovies;
import android.content.Context; import android.view.View; import
android.view.ViewGroup; import android.widget.BaseAdapter; import
android.widget.GridView; import android.widget.ImageView;
import com.squareup.picasso.Picasso;
/** * Created by Tal on 2/24/2016. */ public class ImageAdapter
extends BaseAdapter { // private static String[] desc = new
String[9];
private static String[] desc = {
"http://www.jqueryscript.net/images/jQuery-Ajax-Loading-Overlay-with-Loading-Text-Spinner-Plugin.jpg",
"http://www.jqueryscript.net/images/jQuery-Ajax-Loading-Overlay-with-Loading-Text-Spinner-Plugin.jpg",
"http://www.jqueryscript.net/images/jQuery-Ajax-Loading-Overlay-with-Loading-Text-Spinner-Plugin.jpg",
"http://www.jqueryscript.net/images/jQuery-Ajax-Loading-Overlay-with-Loading-Text-Spinner-Plugin.jpg",
"http://www.jqueryscript.net/images/jQuery-Ajax-Loading-Overlay-with-Loading-Text-Spinner-Plugin.jpg",
"http://www.jqueryscript.net/images/jQuery-Ajax-Loading-Overlay-with-Loading-Text-Spinner-Plugin.jpg",
"http://www.jqueryscript.net/images/jQuery-Ajax-Loading-Overlay-with-Loading-Text-Spinner-Plugin.jpg",
"http://www.jqueryscript.net/images/jQuery-Ajax-Loading-Overlay-with-Loading-Text-Spinner-Plugin.jpg",
"http://www.jqueryscript.net/images/jQuery-Ajax-Loading-Overlay-with-Loading-Text-Spinner-Plugin.jpg",
"http://www.jqueryscript.net/images/jQuery-Ajax-Loading-Overlay-with-Loading-Text-Spinner-Plugin.jpg"
};
private static String[] imageArray = getDesc();
private Context mContext;
//private String[] asc = new String[PostersFragment.getMovieModelListLength()];
private static String[] asc = {};
public ImageAdapter(){
}
public int getCount() {
try{
return imageArray.length;}
catch(NullPointerException e){
e.printStackTrace();
return 0;
}
}
public ImageAdapter(Context c) {
mContext = c;
}
public long getItemId(int position) {
return position;
}
public Object getItem(int position) {
return imageArray[position];
}
// create a new ImageView for each item referenced by the Adapter
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imageView;
if (convertView == null) {
// if it's not recycled, initialize some attributes
imageView = new ImageView(mContext);
int pixels = (int) (mContext.getResources().getDisplayMetrics().density + 0.5f);
imageView.setLayoutParams(new GridView.LayoutParams(185*pixels, 277*pixels));
convertView = imageView;
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
// imageView.setPadding(8, 8, 8, 8);
} else {
imageView = (ImageView) convertView;
}
Picasso.with(mContext).load(imageArray[position])
.placeholder(R.drawable.sample_0)
// .resize(185,277)
.into(imageView);
//imageView.setImageResource(Integer.parseInt(imageArray[position]));
return imageView;
}
public static String[] getAsc() {
return asc;
}
public static void setAsc(String[] asc) {
ImageAdapter.asc = asc;
}
public static String[] getDesc() {
return desc;
}
public static void setImageArray(String[] arrayName){
imageArray = arrayName;
} }
我相信这最后一块应该是最后一点所需的代码，如果完全是布局：
package tk.talcharnes.popularmovies;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.GridView;
import android.widget.Toast;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
/**
* A placeholder fragment containing a simple view.
*/
public class PostersFragment extends Fragment {
private static List<MovieModel> movieModelList;
private static int movieModelListLength;
GridView gridView;
private String done = null;
ImageAdapter adapter;
public PostersFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_main, container, false);
FetchPostersTask fetchPostersTask = (FetchPostersTask) new FetchPostersTask().execute();
// should find gridview on the view which you are creating
gridView = (GridView) view.findViewById(R.id.gridview);
gridView.setAdapter(new ImageAdapter(getContext()));
gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View v,
int position, long id) {
Toast.makeText(getContext(), "You clicked " + movieModelList.get(position).getTitle() ,
Toast.LENGTH_SHORT).show();
}
});
return view;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
private final String BASE_URL = "https://api.themoviedb.org/3/";
private String middle_section = "discover/movie?sort_by=popularity.desc&api_key=";
private String jSonUrl = BASE_URL + middle_section + BuildConfig.MOVIE_DB_API_KEY;
//Get movie posters and data
public class FetchPostersTask extends AsyncTask<Void,Void,Void> {
private final String LOG_TAG = FetchPostersTask.class.getSimpleName();
//will contain raw Json data
String posterJsonString = null;
public Void parseMovieJson()
throws JSONException{
JSONObject jsonParentObject = new JSONObject(posterJsonString);
JSONArray movieJSonArray = jsonParentObject.getJSONArray("results");
movieModelList = new ArrayList<>();
for(int i = 0; i < movieJSonArray.length(); i++){
JSONObject movieJsonObject = movieJSonArray.getJSONObject(i);
MovieModel movieModel = new MovieModel();
movieModel.setTitle(movieJsonObject.getString("title"));
movieModel.setOverview(movieJsonObject.getString("overview"));
movieModel.setPoster_path(movieJsonObject.getString("poster_path"));
movieModel.setRelease_date(movieJsonObject.getString("release_date"));
movieModel.setVote_average(movieJsonObject.getString("vote_average"));
movieModelListLength++;
movieModelList.add(movieModel);
}
return null;
}
@Override
protected Void doInBackground(Void ...params) {
HttpURLConnection urlConnection = null;
BufferedReader reader = null;
//
//will contain raw Json data
// String posterJsonString = null;
try{
//open connection to api
URL url = new URL(jSonUrl);
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.connect();
//read input into string
InputStream inputStream = urlConnection.getInputStream();
StringBuffer buffer = new StringBuffer();
if(inputStream == null){
//nothing else to do in this case
return null;
}
reader = new BufferedReader(new InputStreamReader(inputStream));
String line;
while((line = reader.readLine())!= null){
buffer.append(line + "\n");
}
if(buffer.length()==0){
//nothing here, don't parse
return null;
}
posterJsonString = buffer.toString();
}
catch(MalformedURLException e){
e.printStackTrace();
}
catch(IOException e){
Log.e(LOG_TAG, "Error", e);
return null;
}
finally {
if(urlConnection != null){
urlConnection.disconnect();
}
if(reader != null){
try{
reader.close();
}
catch (final IOException e){
Log.e(LOG_TAG,"Error closing stream", e);
}
}
}
try{
parseMovieJson();;
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
//ImageAdapter.setAsc(movieModelList.);
String[] asc = new String[movieModelList.size()];
for(int i = 0; i < asc.length; i++){
asc[i]=(getMovieModelList().get(i).getPoster_path());
//ImageAdapter.setAsc(asc);
}
adapter.setImageArray(asc);
}
}
public static List<MovieModel> getMovieModelList(){
return movieModelList;
}
public static int getMovieModelListLength(){
return movieModelListLength;
}
}
如果代码有点笨拙，请提前抱歉我是新程序员并且已经注释了一些内容，以确保我可以在以后需要时使用它们。再次提前致谢：D
更新：当我尝试输入代码时：adapter.notifyDataSetChange（）;在adapter.setImageArray（asc）之后;我收到此错误代码：
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".PostersFragment">
<GridView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/gridview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:numColumns="auto_fit"
android:stretchMode="columnWidth"
android:gravity="center"
android:horizontalSpacing="0dp"
android:verticalSpacing="0dp"
android:layout_margin="0dp"
/>
</FrameLayout>
我确实得到了一个类似的错误代码，这是一个数组的空指针错误，当我将数组设置为我已命名为desc的数组时，我以某种方式得到修复，然后我将postersfragment更改为immagearray为asc数组一旦用asynctask完成。不知道为什么这会阻止错误并且几乎修复了它。