Question

在这里，我现在有listView和2个项目，如下图所示

这是用于SimpleAdapter

的ListView

           ListView listProductSup;
           int listItemPos;
           SimpleAdapter pdtAdapter;            
           pdtAdapter = new SimpleAdapter(
                    ProductProgramActivity.this, pdtDataList,
                    R.layout.product_supp_list, new String[]{"pdtSupName", "strKey", "strServQuan", "strMilkQuan", "strWaterQuan", "strDecocQuan", "strPowderQuan"},
                    new int[]{R.id.txt_list_pdt_supp, R.id.key_set, R.id.serve_quan_set, R.id.milk_quan_set, R.id.wat_quan_set, R.id.decoc_quan_set, R.id.pow_quan_set});
            listProductSup.setAdapter(pdtAdapter);
            listProductSup.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                @Override
                public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                    Intent in = null;
                    listItemPos = position;
                    if (categIn.equals("Machine Installation"))
                        in = new Intent(ProductProgramActivity.this, ProgramSettingActivity.class);
                    else if (categIn.equals("Machine Disconnection"))
                        in = new Intent(ProductProgramActivity.this, MachineDisconActivity.class);
                    in.putExtra("idOfIncident", idOfIncident);
                    in.putExtra("orgId", orgId);
                    in.putExtra("assetId", assetId);
                    in.putExtra("pdtId", pdtIdArr.get(position));
                    in.putExtra("pdtSupId", pdtSupIdArr.get(position));
                    startActivityForResult(in,1);
                }
            });

点击列表项后，它会转到next activity。我在该活动中获取textFields的所有值。从那里onBackPressed我发回所有指定的值，如此处

public void backWithData() {
        Intent in = new Intent();
        in.putExtra("pdtSupId", pdtSupId);
        in.putExtra("strKey", strKey);
        in.putExtra("strServQuan", strServQuan);
        in.putExtra("strMilkQuan", strMilkQuan);
        in.putExtra("strWaterQuan", strWaterQuan);
        in.putExtra("strDecocQuan", strDecocQuan);
        in.putExtra("strPowderQuan", strPowderQuan);
        setResult(RESULT_OK, in);
    }
    @Override
    public void onBackPressed() {
        backWithData();
        finish();
    }

在上一个活动中，我通过覆盖onActivityResult来获取所有值。

在这里，我尝试更新ListView的单个项目，该项目被单击以提供所有值。

@Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == 1) {
            if(resultCode == RESULT_OK) {
                pdtSupId = data.getStringExtra("pdtSupId");
                strKey = data.getStringExtra("strKey");
                strServQuan = data.getStringExtra("strServQuan");
                strMilkQuan = data.getStringExtra("strMilkQuan");
                strWaterQuan = data.getStringExtra("strWaterQuan");
                strDecocQuan = data.getStringExtra("strDecocQuan");
                strPowderQuan = data.getStringExtra("strPowderQuan");
                int first = listProductSup.getFirstVisiblePosition();
                int last = listProductSup.getLastVisiblePosition();
                for (int i=0; i<=pdtDataList.size(); i++)
                    if (pdtSupIdArr.get(i).equals(pdtSupId))
                        if (i == listItemPos) {
                            View view = listProductSup.getChildAt(i);
                            listProductSup.getAdapter().getView(i, view, listProductSup);
                            ((TextView)view.findViewById(R.id.key_set)).setText(strKey);
                            ((TextView)view.findViewById(R.id.serve_quan_set)).setText(strServQuan);
                            ((TextView)view.findViewById(R.id.milk_quan_set)).setText(strMilkQuan);
                            ((TextView)view.findViewById(R.id.wat_quan_set)).setText(strWaterQuan);
                            ((TextView)view.findViewById(R.id.decoc_quan_set)).setText(strDecocQuan);
                            ((TextView)view.findViewById(R.id.pow_quan_set)).setText(strPowderQuan);
                            break;
                        }
                 pdtAdapter.notifyDataSetChanged();
            }
        }
    }

但我不知道为什么没有更新。

要更新ListView的单个项目，我参考了SO的其他答案。像Answer 1和其他答案一样。

Answer 1

嗨更新列表onActivity结果中的相应对象然后调用notifyDatasetChanged（），它会自动更新ui ...

Answer 2

您需要更改for循环

 for (int i=0; i<=pdtDataList.size()/.length; i++)

<强>更新

for (int i=0; i<=pdtDataList.length; i++)
                    if (pdtSupIdArr.get(i).equals(pdtSupId))
                        if (i == listItemPos) {
                            View view = listProductSup.getChildAt(i);
                            listProductSup.getAdapter().getView(i, view, listProductSup);
                            ((TextView)view.findViewById(R.id.key_set)).setText(strKey);
                            ((TextView)view.findViewById(R.id.serve_quan_set)).setText(strServQuan);
                            ((TextView)view.findViewById(R.id.milk_quan_set)).setText(strMilkQuan);
                            ((TextView)view.findViewById(R.id.wat_quan_set)).setText(strWaterQuan);
                            ((TextView)view.findViewById(R.id.decoc_quan_set)).setText(strDecocQuan);
                            ((TextView)view.findViewById(R.id.pow_quan_set)).setText(strPowderQuan);
                            break;
                        }
                 pdtAdapter.notifyDataSetChanged();
            }

Answer 3

好吧，在onBackPressed更改相应对象中的数据并调用notifyDataSetChanged()

之前

或者，您可以使用这样的方法（来自我的项目的示例）

private void updateEventInList(boolean likeState, boolean followedState, int comments, int viewsNr, ViewHolder views) {
    if (parentFragment != null && parentFragment instanceof EventListFragment) {
        Log.i(TAG, "Position in list : " + positionInList + "\nlike / follow states : " + likeState + "/" + followedState + "\ncomments number : " + comments + "\nviews number : " + viewsNr);
        ((EventListFragment) parentFragment).updateList(positionInList, likeState, followedState, comments, viewsNr);
    }
}

其中updateList是这样的：

public void updateList(int positionInList, boolean likeState, boolean followedState, int numberOfComments, int numberOfViews) {
    eventsResponses.get(positionInList).setLiked(likeState);
    eventsResponses.get(positionInList).setFollowed(followedState);
    eventsResponses.get(positionInList).setComments(numberOfComments);
    eventsResponses.get(positionInList).setViews(numberOfViews);
    adapter.notifyDataSetChanged();
    Util.hideKeyboard(activity);
}

注意我打电话给adapter.notifyDataSetChanged();。这是listview的适配器。希望这会对你有所帮助

ListView的单个项目未获得更新

3 个答案: