无法使用onItemClickListener获取数据

我想要onItem点击列表视图并进入DetailsPage以显示详细信息，但它让我为空。 ListView中的项目是图片网址，名称和地址。 DetailsPage中的项目是图片网址，名称，地址，联系人和类别。无法使用onItemClickListener获取数据

Image of the view on my phone when get null

这是我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DetailsPage

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) { 

     } 
    }); 
}}

来源

2017-04-22 Brush Lee

你送什么给细节等级：

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

尝试使用此：

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);

来源

2017-04-22 02:53:24 julanove

对不起，我仍然无法得到它。我的DetailsPage中的代码有问题吗？ –

问题先生是您不会将任何内容从ImageListActivity发送到DetailsPage活动，以指示要显示哪个项目。请像上面的Rajesh家伙一样做，看看不同。 – julanove

我们需要从ActivityOne发送一些数据通过意图ActivityTwo然后访问ActivityTwo数据并将其设置为所需的TextView。

请在ActivityOne中查看以下代码。

public class ImageListActivity extends AppCompatActivity { 

private DatabaseReference mDatabaseRef; 
public 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) { 

      ImageUpload itemData = imgList.get(i); 
      Intent intent = new Intent(getApplicationContext(), DetailsOfWorkshops.class); 
      intent.putExtra("name", itemData.getName()); 
      intent.putExtra("address", itemData.getAddress()); 
      intent.putExtra("contact", itemData.getContact());  
      intent.putExtra("category", itemData.getCatogory());  
      startActivity(intent); 
     } 
    }); 
}}

检查出一些变化ActivityTwo

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); 

    String name = getIntent().getStringExtra("name"); 
    String address = getIntent().getStringExtra("address"); 
    String contact = getIntent().getStringExtra("contact"); 
    String category = getIntent().getStringExtra("category"); 


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

    mDatabaseRef = FirebaseDatabase.getInstance().getReference(WorkshopsInfoActivity.FB_DATABASE_PATH); 
    mDatabaseRef.addValueEventListener(new ValueEventListener() { 
     @Override 
     public void onDataChange(DataSnapshot dataSnapshot) { 
      ImageUpload img = dataSnapshot.getValue(ImageUpload.class); 
     } 

     @Override 
     public void onCancelled(DatabaseError databaseError) { 

     } 
    }); 
}}

希望这会有所帮助。

@Rajesh

来源

2017-04-22 04:39:14

非常感谢。这是工作 –

尝试onItemSelected听众，而不是onItemClick监听器这会给你它可以帮助您获得特定对象想要其数据然后你就可以适当值发送额外的位置

 ImageUpload itemData = imgList.get(pos); 
     Intent intent = new Intent(getApplicationContext(), 
     DetailsOfWorkshops.class); 
     intent.putExtra("name", itemData.getName()); 
     intent.putExtra("address", itemData.getAddress()); 
     intent.putExtra("contact", itemData.getContact());  
     intent.putExtra("category", itemData.getCatogory());  
     startActivity(intent);

OnClick监听器适用于整个视图而不是特定元素byt OnSelected给出您在列表中选择的项目的位置查看

来源

2017-04-22 12:35:23

无法使用onItemClickListener获取数据

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