Question

民间。

我的simplecursorAdapter出了问题。一切都很完美，除了滚动列表视图时，它只是混合了包含在自定义布局中的行的收藏夹图标，它只是在滚动时随机出现。你能指导我的代码中有什么问题吗？

提前致谢！

public class AlternateRowCursorAdapter extends SimpleCursorAdapter {

int layoutn;
Cursor localCursor, test;
Bitmap bitImg;
Context localContext;
Bitmap Avatar;
ImageView one, two, three, four, five;
LayoutInflater mInflater;
SQLiteDatabase mDb;
MyDbHelper mHelper;

public static final String TABLE_NAME = "MSGS";
public static final String COL_MsgID = "msgIdc";
public static final String COL_MsgCat = "msgCatC";
public static final String COL_MsgTit = "msgtitleC";
public static final String COL_MsgFavor = "msgFavorC";


public AlternateRowCursorAdapter (Context context, int layout, Cursor c,
        String[] from, int[] to) {

    super(context, R.layout.listtype, c, from, to);

    this.localContext = context;

}


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


    View row = super.getView(position, convertView, parent);

    final Cursor cursbbn = getCursor();

    if (row == null)

    {
        row = ((LayoutInflater) localContext
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE))
                .inflate(R.layout.listtype, null);

    }


    final String Title;
    String SandID;
    final String MsgID;
    final String MsgFav;

    Typeface tf = Typeface.createFromAsset(localContext.getAssets(),"fonts/khalaadsara.ttf");

     Title = cursbbn.getString(2);
     SandID = cursbbn.getString(1);
     MsgID=cursbbn.getString(0);
     MsgFav=cursbbn.getString(4);

    TextView titler = (TextView) row.findViewById(R.id.Sandtit);

    titler.setTypeface(tf);
    titler.setText(Title);



    one = (ImageView) row.findViewById(R.id.imageView5);
    two = (ImageView) row.findViewById(R.id.imageView4);
    three = (ImageView) row.findViewById(R.id.ImageView03);
    four = (ImageView) row.findViewById(R.id.ImageView02);
    five = (ImageView) row.findViewById(R.id.imageView1);


    if(MsgFav.contentEquals("YES"))
    {
        one.setImageResource(R.drawable.favorpress);
    }



    return row;

}

}

编辑：这是我的代码，用于刷新Onresume事件中的值：

private void refreshvalues() {

    mDb = mHelper.getWritableDatabase();

    curs = mDb.query(MyDbHelper.TABLE_NAME, columns, null, null, null,
            null, null,

            null);

    cursF = mDb.query(TABLE_NAME, columns, COL_MsgFavor + "=" + "?",
            new String[] { "YES" }, null, null, COL_MsgTit + " ASC");

    String[] headers = new String[] {MyDbHelper.COL_MsgTit ,MyDbHelper.COL_MsgID};

    mAdapter = new AlternateRowCursorAdapter(this, R.layout.listtype, curs,
            headers, new int[] { R.id.Sandtit});

    fAdapter = new AlternateRowCursorAdapter(this, R.layout.listtype,
            cursF, headers, new int[] { R.id.Sandtit });

    mList.setAdapter(mAdapter);
    fList.setAdapter(fAdapter);

curs.moveToFirst();
cursF.moveToFirst();

mAdapter.notifyDataSetChanged();
fAdapter.notifyDataSetChanged();

mList.invalidateViews();
fList.invalidateViews();

curs.requery();
cursF.requery();

}

Answer 1

首先，您要自定义ListView，该SimpleCustomAdapter需要实现扩展ArrayAdapter，BaseAdapter和getView()中的任何一个的自定义适配器。

现在，你的列表视图搞砸了，因为你没有在视图中保存这些值。您需要编写一个ViewHolder类，它在滚动之前将ListView的视图保持在相同的状态。在Inside if方法中，您需要实现Task语句的else部分。

这是使用ListView的有效方法。请查看以下内容，了解如何实施：例如：

我创建了一个类static class Task { int task_id; String task_brief; String task_priority; String is_completed = "false"; Task(int tmp_task_id, String tmp_task_brief, String tmp_task_priority, String tmp_task_is_completed) { task_id = tmp_task_id; task_brief = tmp_task_brief; task_priority = tmp_task_priority; is_completed = tmp_task_is_completed; } int get_task_id() { return task_id; } String get_task_brief() { return task_brief; } String get_task_priority() { return task_priority; } String get_task_is_completed() { return is_completed; } void set_task_is_completed(String tmp_task_is_completed) { is_completed = tmp_task_is_completed; } }，其中包含数据库中的值：

static class TaskViewHolder {

        TextView tv_task_brief;
        ImageView iv_task_is_completed;

        public TaskViewHolder(TextView tmp_tv_task_brief,
                ImageView tmp_iv_task_is_completed) {
            tv_task_brief = tmp_tv_task_brief;
            iv_task_is_completed = tmp_iv_task_is_completed;
        }

        TextView get_tv_task_brief() {
            return tv_task_brief;
        }

        ImageView get_iv_task_is_completed() {
            return iv_task_is_completed;
        }
    }

现在，我们创建一个包含视图的类TaskViewHolder：

static class TaskAdapter extends ArrayAdapter<Task> {

        LayoutInflater inflater;

        public TaskAdapter(Context context, List<Task> tmp_al_task) {
            super(context, R.layout.single_row_home,
                    R.id.textViewSingleRowHome, tmp_al_task);
            inflater = LayoutInflater.from(context);
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            // TODO Auto-generated method stub

            Task task = (Task) this.getItem(position);

            final ImageView imageView;
            final TextView textView;

            if (convertView == null) {

                convertView = inflater.inflate(R.layout.single_row_home, null);

                imageView = (ImageView) convertView
                        .findViewById(R.id.imageViewSingleRowHome);
                textView = (TextView) convertView
                        .findViewById(R.id.textViewSingleRowHome);

                convertView.setTag(new TaskViewHolder(textView, imageView));

            } else {

                TaskViewHolder viewHolder = (TaskViewHolder) convertView
                        .getTag();
                imageView = viewHolder.get_iv_task_is_completed();
                textView = viewHolder.get_tv_task_brief();
            }

            imageView.setTag(task);

            textView.setText(task.get_task_brief());
            if(task.get_task_priority().equals("High"))
                textView.setTextColor(Color.RED);
            else if(task.get_task_priority().equals("Medium"))
                textView.setTextColor(Color.GREEN);
            else
                textView.setTextColor(Color.BLUE);

            if (task.get_task_is_completed().equals("true")) {

                imageView.setImageResource(R.drawable.action_cancel_icon);
                textView.setPaintFlags(textView.getPaintFlags()
                        | Paint.STRIKE_THRU_TEXT_FLAG);
            } else {

                imageView.setImageResource(R.drawable.action_cancel_icon_2);
                textView.setPaintFlags( textView.getPaintFlags() & (~ Paint.STRIKE_THRU_TEXT_FLAG));
            }

            imageView.setFocusable(false);
            imageView.setFocusableInTouchMode(false);
            imageView.setClickable(true);
            imageView.setOnClickListener(new View.OnClickListener() {

                public void onClick(View v) {

                    Task task = (Task) imageView.getTag();

                    if (task.get_task_is_completed().equals("false")) {


                        imageView.setImageResource(R.drawable.action_cancel_icon);

                        ContentValues values = new ContentValues();
                        values.put("is_completed", "true");

                        database.update("task_info", values, "task_id=?",
                                new String[] { task.get_task_id() + "" });
                        values.clear();

                        textView.setPaintFlags(textView.getPaintFlags()
                                | Paint.STRIKE_THRU_TEXT_FLAG);

                        task.set_task_is_completed("true");

                    } else {

                        imageView.setImageResource(R.drawable.action_cancel_icon_2);

                        ContentValues values = new ContentValues();
                        values.put("is_completed", "false");

                        database.update("task_info", values, "task_id=?",
                                new String[] { task.get_task_id() + "" });
                        values.clear();

                        textView.setPaintFlags( textView.getPaintFlags() & (~ Paint.STRIKE_THRU_TEXT_FLAG));

                        task.set_task_is_completed("false");
                    }
                }
            });

            return convertView;
        }
    }

然后，实现自定义适配器，如下所示：

ListView

注意：一件重要的事情是，如果您的view.setFocusable(false);包含有点击事件的项目，那么这些项目应设置为view.setFocusableInTouchMode(false); view.setClickable(true);和{{ 1}}。我们需要这个，因为ListView将任何视图的click事件作为自己的click事件。此外，视图的click事件应与ListView的Click事件分开。

Answer 2

ListView回收列表项View。因此，请务必致电one.setImageResource()。

if (MsgFav.contentEquals("YES")) {
    one.setImageResource(R.drawable.favorpress);
} else {
    one.setImageResource(R.drawable.default_drawable_as_specified_in_layout);
}

Listview的Simplecursoradapter在滚动时混淆了

2 个答案: