RecyclerAdapter设置适配器位置

我们可以显示数据库中的所有记录没有问题。当我们尝试限制要用sql显示的项目时选择搜索并且RecyclerView适配器填充正确。在列表视图中选择项目时代码失败。列表视图没有得到关于这个记录在什么位置的消息，所以当我们从ListActivity导航到DetailActivity视图不是ListView中的项时，我的问题是如何管理Adapter使用的位置变量？此代码流如下按钮单击MainActivity设置搜索变量转到ListActivity调用DBHelper返回到ListActivity与modelList是阵列列表是设计是MVP所以我们有一个模型类相关的代码如下RecyclerAdapter设置适配器位置

主要活动BTN点击

public void findAllData(View view){ 
    selectSTRING = etFromDate.getText().toString(); 
    Intent intent = new Intent(MainActivity.this, ListActivity.class); 
    startActivity(intent); 
}

ListActivity调用DBHelper注释掉行获取所有数据

 helpher = new DBHelper(this); 
    dbList = new ArrayList<>(); 
    dbList = helpher.getRangeDataFromDB(); 
    //dbList = helpher.getDataFromDB();

DBHelper代码获取所选择的记录或记录，最终

public List<DBModel> getRangeDataFromDB() { 
    List<DBModel> modelList = new ArrayList<>(); 
    db = this.getReadableDatabase(); 
    String query = "SELECT * FROM " + TABLE_INFO + " WHERE " + Col_PURCHASE_DATE + " ='" + selectSTRING + "'"; 
    Cursor cursor = db.rawQuery(query, null); 
    //Cursor cursor = db.rawQuery("SELECT * FROM " + TABLE_INFO + " WHERE " + Col_PURCHASE_DATE + "='" + str + "'" , null); 
    String newBACK = selectSTRING; 

    if (cursor.moveToFirst()) { 
     DBModel model = new DBModel(); 

     while (!cursor.isAfterLast()) { 
      if (newBACK == selectSTRING) { 
       model.setRowid(cursor.getString(0)); 
       model.setStation_Name(cursor.getString(1)); 
       model.setDate_of_Purchase(cursor.getString(2)); 
       model.setGas_Cost(cursor.getString(3)); 
       modelList.add(model); 
       cursor.moveToNext(); 
      } 
     } 
    } 
    int sz = modelList.size(); 
    System.out.println("========= SIZE "+sz); 
    db.close(); 
    return modelList; 
}

现在我们使用的意图去DetailsActivity，这是失败有关发送数据从DBHelper不知道如何写在类的意图回

public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.ViewHolder> { 

static List<DBModel> dbList; 
static private Context context; 

RecyclerAdapter(Context context, List<DBModel> dbList) { 

    RecyclerAdapter.dbList = new ArrayList<>(); 
    RecyclerAdapter.context = context; 
    RecyclerAdapter.dbList = dbList; 
} 

@Override 
public RecyclerAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { 

    View itemLayoutView = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_row, null); 

    // create ViewHolder 
    ViewHolder viewHolder = new ViewHolder(itemLayoutView); 
    return viewHolder; 
} 

@Override 
public void onBindViewHolder(RecyclerAdapter.ViewHolder holder, int position) { 

    holder.rowid.setText(dbList.get(position).getRowid()); 
    holder.station.setText(dbList.get(position).getStation_Name()); 
    System.out.println("========== new position "+position); 


} 

@Override 
public int getItemCount() { 
    return dbList.size(); 
} 

public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener { 

    public TextView station, rowid; 

    public ViewHolder(View itemLayoutView) { 
     super(itemLayoutView); 
     rowid = (TextView) itemLayoutView.findViewById(R.id.rvROWID); 
     station = (TextView) itemLayoutView.findViewById(R.id.rvSTATION); 
     // Attach a click listener to the entire row view 
     itemLayoutView.setOnClickListener(this); 

    } 

    @Override // When an item in DetailsActivity is touched (selected) the RecyclerView has 
    // a OnClickListener attached in the above Code that implements the method below 
    public void onClick(View v) { 
     System.out.println("======RowID "+rowid); 
     Intent intentN = new Intent(context, DetailsActivity.class); 
     Bundle extras = new Bundle(); 
     extras.putInt("POSITION", getAdapterPosition()); 
     extras.putString("FROM_LIST_ACTIVITY", "false"); 
     ///position = getAdapterPosition(); 
     ///position = getLayoutPosition();// Both work the same 
     intentN.putExtras(extras); 
     context.startActivity(intentN); 
    } 
}

思想。这变成意大利面代码！

来源

2017-10-17 James_Duh

解决这个问题是开发商有多个搜索设计在DBHelper分别由不同的按钮对搜索活动这样的设计在DBHelper导致多的ArrayList都具有相同的名称此开车RecycleAdapter疯狂的，因为它触发绑定到ArrayList所以OLD先生布尔救援！这里是修改后的设计代码功能在搜索活动中declare public static Boolean use = false; 并导入需要的地方import static com..MainActivity.use;

下面是每个搜索按钮的代码

public void findAllData(View view){ 
    helper = new DBHelper(this); 
    helper.getDataFromDB(); 
    use = false; 
    // Set Mr. Boolean 
    Intent intent = new Intent(MainActivity.this, ListActivity.class); 
    // ListActivity shows Results of the Search 
    startActivity(intent); 
} 

public void findSelect(View v){ 
    selectSTRING = etFromDate.getText().toString(); 
    // Get your Search variable 
    helper = new DBHelper(this); 
    helper.getDataFromDB(); 
    etToDate.setText(sendBACK); 
    use = true; 
    Intent intent = new Intent(MainActivity.this, ListActivity.class); 
    startActivity(intent); 
}

现在我们做DBHelper所需的搜索

/* Retrive ALL data from database table named "TABLE_INFO" */ 
public List<DBModel> getDataFromDB(){ 
    //String query = "SELECT * FROM " + TABLE_INFO + " WHERE " + Col_PURCHASE_DATE + " > 0 " + " ORDER BY " + Col_ID + " DESC "; 
    /* Notice the SPACES before AND after the words WHERE ORDER BY ASC or DESC most of all the condition " > 0 "*/ 
    /* =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=*/ 
    Cursor cursor = null; 
    List<DBModel> modelList = new ArrayList<>(); 
    if(use == true){ 
     String query = "SELECT * FROM " + TABLE_INFO + " WHERE " + Col_PURCHASE_DATE + " ='" + selectSTRING + "'"; 
     db = this.getWritableDatabase(); 
     cursor = db.rawQuery(query,null); 
    } 
    if(use == false){ 
     String query = "SELECT * FROM " + TABLE_INFO; 
     db = this.getWritableDatabase(); 
     cursor = db.rawQuery(query,null); 
    } 

    if (cursor.moveToFirst()){ 

     do { 
      DBModel model = new DBModel(); 
      model.setRowid(cursor.getInt(0)); 
      model.setStation_Name(cursor.getString(1)); 
      model.setDate_of_Purchase(cursor.getString(2)); 
      model.setGas_Cost(cursor.getString(3)); 
      modelList.add(model); 

      int sz = modelList.size(); 
      int out = model.setRowid(cursor.getInt(0)); 
      String out1 = model.setStation_Name(cursor.getString(1)); 
      String out2 = model.setDate_of_Purchase(cursor.getString(2)); 
      String out3 = model.setGas_Cost(cursor.getString(3)); 
      System.out.println("==============getDataFromDB ID "+out); 
      System.out.println("==============getDataFromDB Station "+out1); 
      System.out.println("==============getDataFromDB Date "+out2); 
      System.out.println("==============getDataFromDB Cost "+out3); 
      System.out.println("======= ======getDataFromDB SIZE "+sz); 

     }while (cursor.moveToNext()); 
    } 
    db.close(); 
    cursor.close(); 
    return modelList; 
}

这个唯一的失足是，如果如果你按日期搜索，并做一个添加到数据库并跳回到ListActivity的新记录不显示我们正在努力保持这种状态敬请关注哈哈好工作James_Duh

来源

2017-10-18 03:49:32 Grendel

我有很多关于设计的问题所以这使得问题如何筛选或添加选定的项目到绑定到ViewHolder的ArrayList看起来VH不与ArrayList同步这很奇怪，如果你删除它会同步并进行尺寸调整 –

你应该设置你的OnClickListener这里：

@Override 
public void onBindViewHolder(ReportAdapter.ViewHolderReport holder, int position) { 
    final Object object = objects.get(position); 
    holder.itemView.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      // Do Something with the object at this position 
     } 
    }); 
}

，而不是你ViewHolder因为你不应该相信在一个时间适配器位置。

来源

2017-10-18 01:27:10 sokarcreative

@sokarcreactive我会尝试这是截至目前不知道如何修改代码，所以我编辑帖子，并显示RecyclerAdapter类的所有代码你能告诉我这将如何解决这个问题？我的绑定是在RecyclerAdapter中，你会放在哪里？ –

当ViewHolders在recyclerview中绘制，屏幕上可见时，已为每个视图调用了OnBindViewHolder。所以你可以确定这个位置上的物体是正确的物体。 – sokarcreative

让我试试你发布的代码谢谢如果我能看到它的话，我会投票它不知道如何设置为我的对象，因为我膨胀CardView来创建与HOLDER绑定的两个TextView你是否使用这个CardView的设计理念作为自己的XML文件？ –

RecyclerAdapter设置适配器位置

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