android - 无法使用 onItemClickListener 获取数据

Question

我想 onItemClick ListView 并转到 DetailsPage 以显示详细信息，但它为我提供了空值。ListView 中的项目是图像 url、名称和地址。DetailsPage中的项目是图片url、名称、地址、联系人和类别。

Image of the view on my phone when get null

这是我的 ListViewPage

public class ImageListActivity extends AppCompatActivity {

private DatabaseReference mDatabaseRef;
private List<ImageUpload> imgList;
private ListView lv;
private ImageListAdapter adapter;
private ProgressDialog progressDialog;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_image_list);
    imgList = new ArrayList<>();
    lv = (ListView) findViewById(R.id.listViewImage);
    progressDialog = new ProgressDialog(this);
    progressDialog.setMessage("Please wait loading list image...");
    progressDialog.show();

    mDatabaseRef = FirebaseDatabase.getInstance().getReference(WorkshopsInfoActivity.FB_DATABASE_PATH);

    mDatabaseRef.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            progressDialog.dismiss();
            for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
                ImageUpload img = snapshot.getValue(ImageUpload.class);
                imgList.add(img);
            }
            adapter = new ImageListAdapter(ImageListActivity.this, R.layout.image_item, imgList);
            lv.setAdapter(adapter);
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

            progressDialog.dismiss();
        }
    });
    lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
            Intent intent = new Intent(getApplicationContext(), DetailsOfWorkshops.class);
            startActivity(intent);
        }
    });
}}

这是我的详情页

public class DetailsOfWorkshops extends AppCompatActivity {

DatabaseReference mDatabaseRef;
List<ImageUpload> listImage;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_details_of_workshops);
    mDatabaseRef = FirebaseDatabase.getInstance().getReference(WorkshopsInfoActivity.FB_DATABASE_PATH);
    mDatabaseRef.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            ImageUpload img = dataSnapshot.getValue(ImageUpload.class);

            String name = img.getName();
            String address = img.getAddress();
            String contact = img.getContact();
            String category = img.getCategory();


            final TextView textViewDetails = (TextView) findViewById(R.id.tvName);
            String string = "Name: " + name + "\nAddress: " + address + "\nContact: " + contact + "\nCategory: " + category + "\n\n";
            textViewDetails.setText(string);
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    });
}}

Answer 1

您没有向详细信息类发送任何内容:

Intent intent = new Intent(getApplicationContext(), DetailsOfWorkshops.class);
        startActivity(intent);

尝试使用这个:

YourClass item = (YourClass) adapterView.getAdapter().getItem(position);
Intent intent = new Intent(getApplicationContext().this, DetailsOfWorkshops.class);
Bundle bundle = new Bundle();
bundle.putString("valueName", value);
intent.putExtra("MyPackage", bundle);
startActivity(intent);