java - ListView 的单个项目未更新

Question

在这里，我的 listView 现在有 2 个项目，如下图所示

这是用于ListView的SimpleAdapter

           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);
                }
            });

单击列表项后，它将转到下一个 Activity 。我正在从该 Activity 中的 textFields 获取所有值。从那里onBackPressed我将发回所有分配的值，如下所示

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 Activity 中，我再次通过重写 onActivityResult 来获取所有值。

在这里，我尝试更新单击以提供所有值的 ListView 的单个项目。

@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();
            }
        }
    }

但我不知道为什么它没有更新。

为了更新ListView的单个项目，我引用了SO的其他答案。喜欢Answer 1以及其他答案。

Answer 1

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