Question

当我点击删除按钮时，我想从数据库中删除特定行以及从列表视图中删除，我试过但我没有收到错误

UserAdapter无法转换为android.content.Context

这是我的适配器

 public class UserAdapter extends BaseAdapter implements  OnTaskCompleted{
    Context context;
    UserAdapter userAdapter;
    Bundle b=new Bundle();
    HashMap<Integer, UserSetter> userSettersClassHashMap;
    int layoutResId;
    String email_id="";
    private HashMap<String, String> postDataParams = null;
    TextView fname,lname,uname,empid,emailid,contact,role;
    Button edit,remove;
    public UserAdapter(Context context, HashMap<Integer, UserSetter> userSettersClassHashMap, int layoutResId) {
        this.context = context;
        this.userSettersClassHashMap = userSettersClassHashMap;
        this.layoutResId = layoutResId;
    }

    @Override
    public int getCount() {
        return userSettersClassHashMap.size();
    }

    @Override
    public Object getItem(int position) {

        return userSettersClassHashMap.get(position);
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

@覆盖 public View getView（final int position，View convertView，ViewGroup parent）{

        View view;

        if (convertView == null) {
            LayoutInflater lf = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = lf.inflate(layoutResId, parent, false);
            view = convertView;

        } else {
            view = convertView;
        }
        fname = (TextView) view.findViewById(R.id.fname);
         emailid= (TextView) view.findViewById(R.id.emailid);
         role= (TextView) view.findViewById(R.id.role);

        remove=(Button) view.findViewById(R.id.remove);
        fname.setText(Html.fromHtml(userSettersClassHashMap.get(position).getFirstname()));
            role.setText(Html.fromHtml(userSettersClassHashMap.get(position).getRoleName()));

        remove.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {


                email_id = String.valueOf(emailid.getText());
                Log.v("email adapter", String.valueOf(email_id));
              callRemove();
                notifyDataSetChanged();

            }
            public void callRemove() {

                postDataParams = new HashMap<>();

                postDataParams.put("email_id", email_id);

                Log.d("postdataparams","->"+postDataParams);
                new WebService(UserAdapter.this, postDataParams, "RemoveList").execute(AppConstants.BASE_URL + AppConstants.REMOVE_DATA);
            }

        });

        return view;

    }

Answer 1

更改此行

new WebService(UserAdapter.this, postDataParams, "RemoveList").execute(AppConstants.BASE_URL + AppConstants.REMOVE_DATA);

到

new WebService(context, postDataParams, "RemoveList").execute(AppConstants.BASE_URL + AppConstants.REMOVE_DATA);

Answer 2

你必须传递上下文而不是USerAdapter.this：

new WebService(context, postDataParams, "RemoveList").execute(AppConstants.BASE_URL + AppConstants.REMOVE_DATA);

在滑动或按钮

2 个答案: