Question

我想让listview看起来像android.All列中的datagrid控件是由动态的代码行为生成的。我的代码片段可以成功构建但是listview没有按照我的预期显示。它有什么问题？

    @Override
        public View getView(int position, View convertView, ViewGroup parentView) {
            ViewHolder holder = null;
            if (convertView == null) {
                synchronized (MainActivity.this) {
                    convertView = mInflater.inflate(id_row_layout, null);
                    holder = new ViewHolder();

//I had add an textView to the convertView,but it not show

                    LinearLayout layout = (LinearLayout) convertView.findViewById(R.id.rLayout);
                    TextView tx = new TextView(context);
                    tx.setText("ads");
                    layout.addView(tx);

                    MyHScrollView scrollView1 = (MyHScrollView) convertView
                            .findViewById(R.id.horizontalScrollView1);

                    holder.scrollView = scrollView1;
                    holder.txt1 = (TextView) convertView
                            .findViewById(R.id.textView1);
                    holder.txt2 = (TextView) convertView
                            .findViewById(R.id.textView2);
                    holder.txt3 = (TextView) convertView
                            .findViewById(R.id.textView3);
                    holder.txt4 = (TextView) convertView
                            .findViewById(R.id.textView4);
                    holder.txt5 = (TextView) convertView
                            .findViewById(R.id.textView5);

                    MyHScrollView headSrcrollView = (MyHScrollView) mHead
                            .findViewById(R.id.horizontalScrollView1);
                    headSrcrollView
                            .AddOnScrollChangedListener(new OnScrollChangedListenerImp(
                                    scrollView1));

                    convertView.setTag(holder);
                    mHolderList.add(holder);
                }
            } else {
                holder = (ViewHolder) convertView.getTag();
            }
            holder.txt1.setText(position + "" + 1);
            holder.txt2.setText(position + "" + 2);
            holder.txt3.setText(position + "" + 3);
            holder.txt4.setText(position + "" + 4);
            holder.txt5.setText(position + "" + 5);

            return convertView;
        }

Answer 1

1) In your adapter with Arraylist override the appropriate constructor
2) In your activity, make your variable data a field (type ArrayList
3) When you add a location you can use data.add(location)
4) Then you can call notifyDatasetChanged() on your adapter

示例代码：http://androidadapternotifiydatasetchanged.blogspot.in/

Answer 2

在ApiDemos中为我提供额外的textView;

public class List14 extends ListActivity {

    private static class EfficientAdapter extends BaseAdapter {
        private LayoutInflater mInflater;
        private Bitmap mIcon1;
        private Bitmap mIcon2;
        private Context context;

        public EfficientAdapter(Context context) {
            // Cache the LayoutInflate to avoid asking for a new one each time.
            mInflater = LayoutInflater.from(context);
this.context = context;
            // Icons bound to the rows.
            mIcon1 = BitmapFactory.decodeResource(context.getResources(), R.drawable.icon48x48_1);
            mIcon2 = BitmapFactory.decodeResource(context.getResources(), R.drawable.icon48x48_2);
        }

        /**
         * The number of items in the list is determined by the number of speeches
         * in our array.
         *
         * @see android.widget.ListAdapter#getCount()
         */
        public int getCount() {
            return DATA.length;
        }

        /**
         * Since the data comes from an array, just returning the index is
         * sufficent to get at the data. If we were using a more complex data
         * structure, we would return whatever object represents one row in the
         * list.
         *
         * @see android.widget.ListAdapter#getItem(int)
         */
        public Object getItem(int position) {
            return position;
        }

        /**
         * Use the array index as a unique id.
         *
         * @see android.widget.ListAdapter#getItemId(int)
         */
        public long getItemId(int position) {
            return position;
        }

        /**
         * Make a view to hold each row.
         *
         * @see android.widget.ListAdapter#getView(int, android.view.View,
         *      android.view.ViewGroup)
         */
        public View getView(int position, View convertView, ViewGroup parent) {
            // A ViewHolder keeps references to children views to avoid unneccessary calls
            // to findViewById() on each row.
            ViewHolder holder;

            // When convertView is not null, we can reuse it directly, there is no need
            // to reinflate it. We only inflate a new View when the convertView supplied
            // by ListView is null.
            if (convertView == null) {
                convertView = mInflater.inflate(R.layout.list_item_icon_text, null);

                // Creates a ViewHolder and store references to the two children views
                // we want to bind data to.
                holder = new ViewHolder();
                holder.text = (TextView) convertView.findViewById(R.id.text);
                holder.icon = (ImageView) convertView.findViewById(R.id.icon);
                LinearLayout layout = (LinearLayout) convertView.findViewById(R.id.layout);
                TextView child = new TextView(context);
                child.setText("CHILD");
                layout.addView(child);

                convertView.setTag(holder);
            } else {
                // Get the ViewHolder back to get fast access to the TextView
                // and the ImageView.
                holder = (ViewHolder) convertView.getTag();
            }

            // Bind the data efficiently with the holder.
            holder.text.setText(DATA[position]);
            holder.icon.setImageBitmap((position & 1) == 1 ? mIcon1 : mIcon2);

            return convertView;
        }

        static class ViewHolder {
            TextView text;
            ImageView icon;
        }
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setListAdapter(new EfficientAdapter(this));
    }

    private static final String[] DATA = {
            "Abbaye de Belloc", "Abbaye du Mont des Cats", "Abertam",
           };
}

enter image description here

检查您的静态holder和layouts。

Answer 3

很容易有一个额外的列，只显示和隐藏所选位置的元素。一旦元素未显示，您必须隐藏它们。

事实上，你也可以从适配器中膨胀RelativeLayout，但这可能更难实现。

希望有所帮助

Answer 4

如果每行的Row文件布局相同，那么

您只需添加项目数（换言之，您的列）

到ArrayList（负责填充listview adapter）并致电notifydatasetchanged(true)或adapter.notifyDataSetChanged()

我可以在运行时在listview中插入一列吗？

4 个答案: