Question

大家好我想在一个列表中水平显示多个项目。从具有两个按钮确定和取消的对话框中选择此项目。单击“确定”时，它应从编辑文本中选择值，并从对话框中选择字符串值，并在列表中水平显示。

Array List Adapter
public class VehicleListAdapter extends ArrayAdapter<String> {
private Context context;
private List<String> vehicle_no;
public VehicleListAdapter(Context context, int resource, List<String> objects) {
    super(context, resource, objects);
    this.context = context;
    this.vehicle_no = objects;


}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    //get the vehicle number we are displaying
    String my_vehicle = vehicle_no.get(position);

    //get the inflater and inflate the XML layout for each item
    LayoutInflater inflater = (LayoutInflater) context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
    View view = inflater.inflate(R.layout.vehicle_num_layout, null);
    TextView txt_vehicle_num = (TextView) view.findViewById(R.id.txt_vehicle_num);
    txt_vehicle_num.setText(my_vehicle);
    return view;
}

}

Activity with the list
button.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {

            // get prompts.xml view
            LayoutInflater li = LayoutInflater.from(context);
            View promptsView = li.inflate(R.layout.prompts, null);

            AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(
                    context);

            // set prompts.xml to alertdialog builder
            alertDialogBuilder.setView(promptsView);

            final EditText userInput = (EditText) promptsView
                    .findViewById(R.id.editTextDialogUserInput);

            // set dialog message
            alertDialogBuilder
                    .setCancelable(false)
                    .setPositiveButton("OK",
                            new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog, int id) {
                                    // get user input and set it to result
                                    // edit text

                                    if(userInput.getText().toString().trim().length()==0) {
                                        userInput.setError("Vehicle Number Required");
                                        focus.start();
                                        String stime = focus.getText().toString();


                                    }
                                    else {
                                        result.setText(userInput.getText());
                                        ListView list = (ListView) findViewById(R.id.list);
                                        vehicle_list.add(userInput.getText().toString().trim());
                                        VehicleListAdapter listAdapter = new VehicleListAdapter(StartWatch.this, 0, vehicle_list);
                                        list.setAdapter(listAdapter);
                                    }
                                }
                            })
                    .setNegativeButton("Cancel",
                            new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog, int id) {
                                    dialog.cancel();
                                }
                            });

            // create alert dialog
            AlertDialog alertDialog = alertDialogBuilder.create();

            // show it
            alertDialog.show();

        }
    });

Answer 1

首先，每当用户点击确定对话框时，为什么要创建新的列表视图。从对话框正面按钮单击中删除此行ListView list = (ListView) findViewById(R.id.list);。

在正面按钮中单击

后，按如下所示添加行

VehicleListAdapter listAdapter = new VehicleListAdapter(StartWatch.this, 0, vehicle_list);
list.setAdapter(listAdapter);
listAdapter.notifyDataSetChanged(); // Add this line to tell adapter that data has been changed

在数组列表

1 个答案: