Question

我正在尝试从非活动类中更改ImageView的src并同时显示错误对话框消息，对话框消息出现但在ImageView的src上没有任何更改这是我的代码使用inflater，我不知道是什么问题。

with recursive r as (
    -- start with "required_people" as "missing_required_people" in the whole range
    select 0 iteration,
           id group_id,
           array[]::int[] used_assignment_ids,
           -- build a json map, where keys are the time ranges
           -- and values are the number of missing people for that range
           jsonb_build_object(tsrange(start_time, end_time), required_people) required_people_per_time_range
    from   groups
    where  required_people > 0
    and    id = 1 -- query parameter
  union all
    select r.iteration + 1,
           r.group_id,
           r.used_assignment_ids || a.assignment_id,
           d.required_people_per_time_range
    from   r
    -- join a single assignment to the previous iteration, where
    -- the assigment's time range overlaps with (at least one) time range,
    -- where there is still missing people. when there are no such time range is
    -- found in assignments, the "recursion" (which is really just a loop) stops
    cross join lateral (
      select     a.id assignment_id, tsrange(start_time, end_time) time_range
      from       people_assignments a
      cross join (select key::tsrange time_range from jsonb_each(r.required_people_per_time_range)) j
      where      a.group_id = r.group_id
      and        a.id <> ALL (r.used_assignment_ids)
      and        tsrange(start_time, end_time) && j.time_range
      limit      1
    ) a
    -- "partition" && accumulate all remaining time ranges with
    -- the one found in the previous step
    cross join lateral (
      -- accumulate "partition" results
      select jsonb_object_agg(u.time_range, u.required_people) required_people_per_time_range
      from   (select key::tsrange time_range, value::int required_people
              from   jsonb_each_text(r.required_people_per_time_range)) j
      cross join lateral (
        select u time_range, j.required_people - case when u && a.time_range then 1 else 0 end required_people
        -- "partition" the found time range with all existing ones, one-by-one
        from   unnest(case
                 when j.time_range @> a.time_range
                 then array[tsrange(lower(j.time_range), lower(a.time_range)), a.time_range, tsrange(upper(a.time_range), upper(j.time_range))]
                 when j.time_range && a.time_range
                 then array[j.time_range * a.time_range, j.time_range - a.time_range]
                 else array[j.time_range]
               end) u
        where not isempty(u)
      ) u
    ) d
),
-- select only the last iteration
l as (
  select   group_id, required_people_per_time_range
  from     r
  order by iteration desc
  limit    1
)
-- unwind the accumulated json map
select     l.group_id, lower(time_range) start_time, upper(time_range) end_time, missing_required_people
from       l
cross join lateral (
  select key::tsrange time_range, value::int missing_required_people
  from   jsonb_each_text(l.required_people_per_time_range)
) j
-- select only where there is still some missing people
-- this is optional, if you omit it you'll also see row(s) for sub-ranges where
-- there is enough people in the group (these rows will have zero,
-- or negative amount of "missing_required_people")
where      j.missing_required_people > 0

更新：完成课程

 LayoutInflater inflater = (LayoutInflater) getContext().getSystemService( Context.LAYOUT_INFLATER_SERVICE );
        View view = inflater.inflate( R.layout.control_fragment, null );

        ImageView imgView = (ImageView)view.findViewById(R.id.okimg);
        imgView.setImageResource(R.drawable.clear);

Answer 1

runOnUiThread(new Runnable() {

   @Override
   public void run() {
       LayoutInflater inflater = (LayoutInflater) getContext().getSystemService( Context.LAYOUT_INFLATER_SERVICE );
    View view = inflater.inflate( R.layout.control_address_fragment, null );

    ImageView okaddress = (ImageView)view.findViewById(R.id.address_ok);

    okaddress.setImageResource(R.drawable.clear);
   }
});

将您的UI更改移至MainThread。只会反映这些

利用functino runOnUIThread（），这会将您的指令传递给mainthread，从而更新UI。您还可以在此api中移动与UI相关的逻辑

Answer 2

您可以在ImageView

中设置Fragment静态内容

public class YourFragment extends Fragment{
public static ImageView okaddress;
@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.control_address_fragment, container, false);

okaddress = (ImageView)view.findViewById(R.id.address_ok);
}

return view;
}

当结果为0时，如你所说，你可以在AddressControl

中改变它

YourFragment.okaddress.setImageResource(R.drawable.clear);

Answer 3

我通过Fragment中的ImageView更改源而不是非活动类来解决我的问题，但是直到现在需要知道为什么我们不能通过以前的方式（从普通类）更改ImageView？

我无法在Android中的非活动类中更改imageview的src

3 个答案: