Question

我正在尝试从SQLite数据库中删除数据，但它无法正常工作。

请参阅SQlite数据库 DELETE 查询：

public void deleteCompany(long company_id) {
    SQLiteDatabase db = dbHelper.getWritableDatabase();

    db.delete(COMPANY, KEY_ID + " = ?", new String[] { String.valueOf(company_id) });
}

我在哪里删除数据 CompaniesFragment.java ：

rvCompanies_view.addOnItemTouchListener(new RecyclerTouchListener(getActivity().getApplicationContext(), rvCompanies_view, new AddAffiliatedCompanyActivity.ClickListener() {
    @Override
    public void onLongClick(final View child, final int childPosition) {

        final AlertDialog.Builder alertDialog = new AlertDialog.Builder(getActivity(), R.style.Theme_AppCompat_DayNight_Dialog);
        alertDialog.setTitle("Confirm Delete...");  
        alertDialog.setMessage("Are you sure you want delete this Company?");

        alertDialog.setPositiveButton("YES", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog,int which) {
                myDb.deleteCompany(childList.get(childPosition).getId());
                childList.remove(childPosition);
                adapterRecycler.notifyDataSetChanged();
                Toast.makeText(getActivity().getApplicationContext(), "Company Deleted", Toast.LENGTH_SHORT).show();
            }
        });
        alertDialog.setNegativeButton("NO", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                dialog.cancel();
            }
        });
        alertDialog.show();
    }

    @Override
    public void onClick(View child, int childPosition) {
    }
}));

下面的代码可以在RecyclerView上找到，但是我将单独定义以便了解击球手：

myDb.deleteCompany(childList.get(childPosition).getId());
childList.remove(childPosition);
adapterRecycler.notifyDataSetChanged();
Toast.makeText(getActivity().getApplicationContext(), "Company Deleted", Toast.LENGTH_SHORT).show();

更新

我将更改我的代码，见下文：

Log.e("TAG", "Size Of Array :" + childList.size());
                        Log.e("TAG", "Id" + childList.get(childPosition).getId());
    myDb.deleteCompany(childList.get(childPosition).getId());
                        childList.remove(childPosition);
                        adapterRecycler.notifyItemRemoved(childPosition);
                        //adapterRecycler.notifyDataSetChanged();
                        //Log.d("ADebugTag", "Value: " + childList);
                        Toast.makeText(getActivity().getApplicationContext(), "Company Deleted", Toast.LENGTH_SHORT).show();

并且它给我带来了错误： java.lang.IndexOutOfBoundsException: Invalid index 2, size is 2

这只是一个Toast消息，只删除数据或任何东西

Answer 1

尝试使用

adapterRecycler.notifyItemRemoved(childPosition)
adapterRecycler.notifyItemRangeChanged(childPosition, getItemCount());

而不是

adapterRecycler.notifyDataSetChanged();

Answer 2

解决问题：

问题是数据位置

第一个问题在线下：

 List<Company> childList = new ArrayList<Company>();

上面的行创建了一个问题，我的数组列表becoze我会使用这个适配器变量becoz，我不能得到任何数组大小

所以我打印 LOG 并查看数组大小：

Log.e("TAG", "Size Of Array :" + childList.size() + "Position :" + childList);

第二个我打印 LOG 我的数据ID：

Log.e("TAG", "Id" + childList.get(childPosition).getId());

然后我理解数据是以DESC顺序显示的，我将改变我的上一行，如我的下线：

Log.e("TAG", "Id" + childList.get(childPosition - 1 ).getId());

然后我使用下面的行删除我的记录：

myDb.deleteCompany(childList.get(childPosition).getId());

上面一行删除一条记录，但如果在数组1记录中假设，那么就生成错误。

然后我将更改代码：

myDb.deleteCompany(childList.get(childPosition - 1 ).getId());

我的问题已解决

请参阅我的解决方案的完整代码：

Log.e("TAG", "Size Of Array :" + childList.size() + "Position :" + childList);
Log.e("TAG", "Id" + childList.get(childPosition - 1 ).getId());
myDb.deleteCompany(childList.get(childPosition - 1 ).getId());
rvCompanies_view.removeViewAt(childPosition);
Log.e("TAG", "Size Of Array :" + childList.size() + "Position :" + childList);
adapterRecycler.notifyDataSetChanged();
Toast.makeText(getActivity().getApplicationContext(), "Company Deleted", Toast.LENGTH_SHORT).show();

Answer 3

将接口设置为回收器视图适配器，用于点击句柄，如下面的代码..

 onItemClickListner onItemClickListner;

public void setOnItemClickListner(RecyclerViewAdpater.onItemClickListner onItemClickListner) {
    this.onItemClickListner = onItemClickListner;
}

public interface onItemClickListner {
    void onClick(String str);//pass your object types.
}


  @Override
public void onBindViewHolder(ItemViewHolder holder, int position) {
    String data = mStringList.get(position); // if you pass object of class then create that class object.

    // below code handle click event on recycler view item.
    holder.itemView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            onItemClickListner.onClick(data);
        }
    });

然后在活动之后将适配器绑定到Recycler视图后面放下代码..

        recyclerViewAdpater.setOnItemClickListner(new RecyclerViewAdpater.onItemClickListner() {
        @Override
        public void onClick(String str) {
            // here you show your alert dialog.
            // below code remove item from list
            stringsList.remove(stringsList.indexOf(str));
            recyclerViewAdpater.notifyDataSetChanged();
        }
    });

我的RecyclerView中没有删除SQLite数据

3 个答案: