无法将数据从RecyclerView适配器传递到Viewpager适配器
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我正在创建简单的图库应用程序,其中图像显示在RecyclerView内的MainActivity上,点击任意图像,它将把我们带到SlideActivity,我想在ViewPager上显示图像,然后我们刷扫所有图像应该显示在ViewPager上。为了检索图像,我正在使用Glide。 RecyclerView上的图像加载非常好但是当我点击任何图像时我得到这个例外“java.lang.ArrayIndexOutOfBoundsException:length = 15; index = -1”。我知道有很多相同的问题,我看到所有的代码,但没有理解,所以最后决定提出问题我粘贴代码,无论我到现在为止。任何建议或建议都会有所帮助bcz我独自工作我没有导师而我正在学习。谢谢!
错误:
java.lang.ArrayIndexOutOfBoundsException: length=15; index=-1
at java.util.ArrayList.get(ArrayList.java:439)
at com.starmoonsolutions.imagegallery.RecycleViewAdapter$ViewHolder$1.onClick(RecycleViewAdapter.java:63)
at android.view.View.performClick(View.java:6256)
at android.view.View$PerformClick.run(View.java:24697)
at android.os.Handler.handleCallback(Handler.java:789)
at android.os.Handler.dispatchMessage(Handler.java:98)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6541)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
image URL.Java
public class ImageUrl {
String imageUrl;
public String getImageUrl() {
return imageUrl;
}
public void setImageUrl(String imageUrl) {
this.imageUrl = imageUrl;
}
}
主要内容:
public class MainActivity extends AppCompatActivity {
private ImageView imageView;
RecyclerView recyclerView;
GridLayoutManager gridLayoutManager;
ArrayList<ImageUrl> imageUrlList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
imageView = findViewById(R.id.imageView);
recyclerView = findViewById(R.id.recyclerView);
gridLayoutManager = new GridLayoutManager(getApplicationContext(), 2);
recyclerView.setLayoutManager(gridLayoutManager);
imageUrlList = prepareData();
RecycleViewAdapter galleryAdapter = new RecycleViewAdapter(getApplicationContext(), imageUrlList);
recyclerView.setAdapter(galleryAdapter);
}
private ArrayList prepareData(){
// here you should give your image URLs and that can be a link from the Internet
String imageUrls[] = {
"https://images.pexels.com/photos/358457/pexels-photo-358457.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=750&w=1260",
"https://images.pexels.com/photos/934964/pexels-photo-934964.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=650&w=940",
"https://images.pexels.com/photos/1202887/pexels-photo-1202887.jpeg?auto=compress&cs=tinysrgb&h=650&w=940",
"https://images.pexels.com/photos/337909/pexels-photo-337909.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=650&w=940",
"https://images.pexels.com/photos/894443/pexels-photo-894443.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=650&w=940",
"https://images.pexels.com/photos/951325/pexels-photo-951325.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=650&w=940",
"https://images.pexels.com/photos/1534411/pexels-photo-1534411.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=650&w=940",
"https://images.pexels.com/photos/266436/pexels-photo-266436.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=650&w=940",
"https://images.pexels.com/photos/1894350/pexels-photo-1894350.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=650&w=940",
"https://images.pexels.com/photos/87009/earth-soil-creep-moon-lunar-surface-87009.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=650&w=940",
"https://images.pexels.com/photos/1820563/pexels-photo-1820563.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=650&w=940",
"https://images.pexels.com/photos/1274260/pexels-photo-1274260.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=650&w=940"
};
imageUrlList = new ArrayList<>();
for (int i = 0; i < imageUrls.length; i++) {
ImageUrl imageUrl = new ImageUrl();
imageUrl.setImageUrl(imageUrls[i]);
imageUrlList.add(imageUrl);
}
Log.d("MainActivity", "List count: " + imageUrlList.size());
return imageUrlList;
}
}
RecyclerViewAdapter:
public class RecycleViewAdapter extends RecyclerView.Adapter<RecycleViewAdapter.ViewHolder>{
private ArrayList<ImageUrl> imageUrls;
private Context context;
public RecycleViewAdapter(Context context, ArrayList<ImageUrl> imageUrls) {
this.imageUrls = imageUrls;
this.context = context;
}
@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.image_layout, viewGroup, false);
return new ViewHolder(view);
}
/**
* gets the image url from adapter and passes to Glide API to load the image
*
* @param viewHolder
* @param i
*/
@Override
public void onBindViewHolder(@NonNull ViewHolder viewHolder, int i) {
Glide.with(context).load(imageUrls.get(i).getImageUrl()).into(viewHolder.img);
}
@Override
public int getItemCount() {
return imageUrls.size();
}
public class ViewHolder extends RecyclerView.ViewHolder{
RecyclerView recyclerView;
ImageView img;
public ViewHolder(@NonNull final View itemView) {
super(itemView);
img = itemView.findViewById(R.id.imageView);
recyclerView = itemView.findViewById(R.id.recyclerView);
final int pos = getAdapterPosition();
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(context, SlideActivity.class);
error point here-> intent.putExtra("image", String.valueOf(imageUrls.get(pos).getImageUrl())); <- error point here
intent.putExtra("position", pos);
intent.putExtra("list", imageUrls.get(pos).imageUrl);
context.startActivity(intent);
}
});
}
}
}
SlideActivity(ViewPager):
public class SlideActivity extends AppCompatActivity {
private ViewPager viewPager;
private Context context = SlideActivity.this;
private ViewPagerAdapter adapter;
private ArrayList<String> list;
String image;
private int position;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.slide_activity);
viewPager = findViewById(R.id.viewPager);
getIntentInfo();
adapter = new ViewPagerAdapter(list,context);
viewPager.setAdapter(adapter);
viewPager.setCurrentItem((position));
}
private void getIntentInfo() {
image = getIntent().getStringExtra("image");
list = getIntent().getStringArrayListExtra("list");
position = getIntent().getIntExtra("position",0);
}
}
ViewPagerAdapter:
public class ViewPagerAdapter extends PagerAdapter {
private ArrayList<String> imageUrls;
private android.content.Context context;
private LayoutInflater inflater;
private ImageView wallpaper;
public ViewPagerAdapter() {
}
public ViewPagerAdapter(ArrayList<String> imageUrls, android.content.Context context) {
this.imageUrls = imageUrls;
this.context = context;
}
@Override
public int getCount() {
return imageUrls.size();
}
@Override
public boolean isViewFromObject(@NonNull View view, @NonNull Object o) {
return view.equals(o);
}
@NonNull
@Override
public Object instantiateItem(@NonNull final ViewGroup container, final int position) {
inflater = LayoutInflater.from(container.getContext());
View view = inflater.inflate(R.layout.pager_item, container, false);
wallpaper = view.findViewById(R.id.walpaperImage);
Glide.with(context).asBitmap().load(imageUrls.get(position)).into(wallpaper);
container.addView(view, 0);
return view;
}
@Override
public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {
container.removeView((View) object);
}
}
实际上问题在于获得适配器位置。
public ViewHolder(@NonNull final View itemView) {
super(itemView);
img = itemView.findViewById(R.id.imageView);
recyclerView = itemView.findViewById(R.id.recyclerView);
// remove the below line
//final int pos = getAdapterPosition();
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(context, SlideActivity.class);
// you need to freshly get the adapter position here.
int pos = getAdapterPosition();
error point here-> intent.putExtra("image", String.valueOf(imageUrls.get(pos).getImageUrl())); <- error point here
intent.putExtra("position", pos);
intent.putExtra("list", imageUrls.get(pos).imageUrl);
context.startActivity(intent);
}
});
}
由于ViewHolder被回收,因此适配器位置可能会发生变化,因此您需要在单击侦听器中获取最新的适配器位置。
关于Bundle数据,传递'String'类型的URL列表而不是自定义对象,
public void onClick(View v) {
Intent intent = new Intent(context, SlideActivity.class);
error point here-> intent.putExtra("image", String.valueOf(imageUrls.get(pos).getImageUrl())); <- error point here
intent.putExtra("position", pos);
// imageUrls is of type ArrayList<String>
intent.putStringArrayListExtra("list", imageUrls);
context.startActivity(intent); }
或者使用Parcelable library来序列化自定义对象。
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