如何在已填充列表的 listView 中添加列表？

Question

我想知道如何向 listView 添加新项目，其中 listView 已经填充了数据？

在Edit_Staff_Benefit_ListView中，有一个add button, listView (value get from SQLite).

当点击添加按钮时，它会转到Edit_Staff，最后return值变为Edit_Staff_Benefit_ListView.

下图显示Edit_Staff_Benefit_ListView。如您所见，它有一个列表，该列表是从 SQLite 中检索到的。

Edit_Staff_Benefit_ListView

public class Edit_Staff_Benefit_ListView extends Fragment {

    PicCustomBaseAdapter obj;
    ArrayList<ImageAndText> images=new ArrayList<ImageAndText>();
    ListView listViewEdit;
    StaffAPI sqlcon;
    private SimpleCursorAdapter dataAdapter;
    public static final int PROJECT_REQUEST_CODE = 1;
    public static final int CAMERA_REQUEST_CODE = 2;


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View edit_details = inflater.inflate(R.layout.edit_staff_list, container, false);
        listViewEdit = (ListView)edit_details. findViewById(R.id.listViewEditStaff);
        add=(Button)edit_details.findViewById(R.id.button4);
        dbHelper = new MyDatabaseHelper(getActivity());
        sqlcon = new StaffAPI(getActivity());
        Bundle bundle = this.getArguments();
        if (getArguments() != null) {
            ID = bundle.getLong("ID");
            BuildEditStaffList(ID);
        }

      add.setOnClickListener(new View.OnClickListener()
 {
            @Override
            public void onClick(View v) {
                mClickedPosition = -1;
                Intent intent = new Intent(getActivity(), Edit_Staff.class);
                //Log.e("ST","S");
                startActivityForResult(intent, PROJECT_REQUEST_CODE);
            }
        });
          return edit_details;
    }

    public void BuildEditStaffList(long id) // retrieve data from SQLite 
    {

        sqlcon.open();
        Cursor cursor1=sqlcon.readName(id);

        String[] columns=new String[]{
                MyDatabaseHelper.Image,MyDatabaseHelper.Claim_Type,MyDatabaseHelper.Amount,MyDatabaseHelper.Description};

        int[] to=new int[]
                {
                        R.id.image, R.id.type,R.id.amount,R.id.description};

        dataAdapter = new SimpleCursorAdapter(getActivity(), R.layout.retrieve_staff,
                cursor1,
                columns,
                to,
                0);

        dataAdapter.setViewBinder(new MyViewBinder());
        listViewEdit.setAdapter(dataAdapter);
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) { // receive from Activity EditStaff and populate to ListView 
        if (resultCode == Activity.RESULT_OK) {
            if (requestCode == PROJECT_REQUEST_CODE) {
                ReceiveType = data.getStringExtra("type");
                ReceiveDescription = data.getStringExtra("description");
                ReceiveAmount = data.getStringExtra("amount");
                ReceiveImage = data.getParcelableExtra("photo");
                if (mClickedPosition == -1) {  // if icon clicked
                    if (obj != null) {
                        obj = new PicCustomBaseAdapter(getActivity(),images,listViewEdit);
                        listViewEdit.setAdapter(obj);
                        obj.addNewItem1(ReceiveType, ReceiveAmount, ReceiveImage, ReceiveDescription);
                    }
                }

Edit_Staff

save.setOnClickListener(new View.OnClickListener() { // return value to Edit_Staff_Benefit_ListView
            @Override
            public void onClick(View v) {

                Intent returnIntent = new Intent();
                Amount = amount.getText().toString();
                Description = description.getText().toString();
                claimType = type.getSelectedItem().toString();
                returnIntent.putExtra("type", claimType);
                returnIntent.putExtra("description", Description);
                returnIntent.putExtra("amount", Amount);
                returnIntent.putExtra("photo", photo);
                setResult(Activity.RESULT_OK, returnIntent);
                finish();

            }
        });
    }

PicCustomBaseAdapter

public class PicCustomBaseAdapter extends BaseAdapter {

    private static ArrayList<ImageAndText> imgAndText;
    FrameLayout footerLayout;
    private LayoutInflater mInflater;
    ListView listview;


    public PicCustomBaseAdapter(Context context, ArrayList<ImageAndText> img,ListView listview) {
        imgAndText = img;
        this.listview=listview;
        mInflater = LayoutInflater.from(context);
    }

    public void addNewItem1(String type,String amount, Bitmap imageFromClaims,String description)
    {
        ImageAndText image = new ImageAndText();
        image.setType(" Claims Type : " + type);
        image.setAmount(" Amount : " + amount);
        image.setImage(imageFromClaims);
        image.setDescription(" Description : " + description);
        imgAndText.add(image);
        this. notifyDataSetChanged();
    }


    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;
        if (convertView == null) {
            convertView = mInflater.inflate(R.layout.custom_image_and_text, null);
            holder = new ViewHolder();
            holder.txtType= (TextView) convertView.findViewById(R.id.ListType);
            holder.txtDescription = (TextView) convertView.findViewById(R.id.ListDescription);
            holder.txtAmount = (TextView) convertView.findViewById(R.id.ListAmount);
           holder.picture=(ImageView)convertView.findViewById(R.id.photo);

            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        holder.txtType.setText(imgAndText.get(position).getType());
        holder.txtDescription.setText(imgAndText.get(position).getDescription());
        holder.txtAmount.setText(imgAndText.get(position).getAmount());
        holder.picture.setImageBitmap(imgAndText.get(position).getImage());

        return convertView;
    }

    static class ViewHolder {
        TextView txtType;
        TextView txtDescription;
        TextView txtAmount;
        ImageView picture;
    }
}

So the issue now is when I click the save button in Edit_Staff and return to Edit_Staff_Benefit_ListView, a list supposes to be added. But I still get the same list. What's wrong here ?

Answer 1

因为您正在创建自定义适配器的新对象并将其设置为列表视图，如果未创建对象但如果它已经创建则不会向其适配器添加数据

首先在 Activity

的 onCreate() 中创建自定义适配器

obj = new PicCustomBaseAdapter(getActivity(),images,listViewEdit);
listViewEdit.setAdapter(obj);

然后更改ActivityResult()

if (obj != null) {
    obj = new PicCustomBaseAdapter(getActivity(),images,listViewEdit);
    listViewEdit.setAdapter(obj);
    obj.addNewItem1(ReceiveType, ReceiveAmount, ReceiveImage, ReceiveDescription);
}

到

obj.addNewItem1(ReceiveType, ReceiveAmount, ReceiveImage, ReceiveDescription);

或

if (obj != null) {
    obj = new PicCustomBaseAdapter(getActivity(),images,listViewEdit);
    listViewEdit.setAdapter(obj);
    obj.addNewItem1(ReceiveType, ReceiveAmount, ReceiveImage, ReceiveDescription);
} else {
    obj.addNewItem1(ReceiveType, ReceiveAmount, ReceiveImage, ReceiveDescription);
}

将适配器更改为

public class PicCustomBaseAdapter extends BaseAdapter {

private static ArrayList<ImageAndText> imgAndText;
FrameLayout footerLayout;
private LayoutInflater mInflater;
ListView listview;
boolean mFirstTime = true;

public PicCustomBaseAdapter(Context context, ArrayList<ImageAndText> img,ListView listview) {
    imgAndText = img;
    this.listview=listview;
    mInflater = LayoutInflater.from(context);
}

public void addNewItem1(String type,String amount, Bitmap imageFromClaims,String description)
{
    if(mFirstTime){
        imgAndText.clear();
        mFirstTime = false;
    }
    ImageAndText image = new ImageAndText();
    image.setType(" Claims Type : " + type);
    image.setAmount(" Amount : " + amount);
    image.setImage(imageFromClaims);
    image.setDescription(" Description : " + description);
    imgAndText.add(image);
    this. notifyDataSetChanged();
}


public View getView(int position, View convertView, ViewGroup parent) {
    ViewHolder holder;
    if (convertView == null) {
        convertView = mInflater.inflate(R.layout.custom_image_and_text, null);
        holder = new ViewHolder();
        holder.txtType= (TextView) convertView.findViewById(R.id.ListType);
        holder.txtDescription = (TextView) convertView.findViewById(R.id.ListDescription);
        holder.txtAmount = (TextView) convertView.findViewById(R.id.ListAmount);
       holder.picture=(ImageView)convertView.findViewById(R.id.photo);

        convertView.setTag(holder);
    } else {
        holder = (ViewHolder) convertView.getTag();
    }

    holder.txtType.setText(imgAndText.get(position).getType());
    holder.txtDescription.setText(imgAndText.get(position).getDescription());
    holder.txtAmount.setText(imgAndText.get(position).getAmount());
    holder.picture.setImageBitmap(imgAndText.get(position).getImage());

    return convertView;
}

static class ViewHolder {
    TextView txtType;
    TextView txtDescription;
    TextView txtAmount;
    ImageView picture;
}
}

Answer 2

您可以使用适配器 NotifyChange 从列表视图添加新项目。

images.add(NewAdapterItemObject);

和

obj.notifyDataSetChanged();

完成了。

如何在已填充列表的 listView 中添加列表？

How do I add a list in listView where the list has been populated?

sqlite

android

listview

android-listview