android popup window not displaying

问题:

I am creating a popup window with a listview. In the listview each row contains a textbox and radio button but the popup window not displaying. I can't figure out the mistake.

This is the code.

import java.util.List;
import java.util.Vector;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.SharedPreferences;
import android.graphics.Typeface;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.PopupWindow;
import android.widget.RadioButton;
import android.widget.TextView;
public class SettingsActivity extends Activity {

PopupWindow popup;
ListView fontSizeListView;
View popupView;
int currentFontSize;
Vector<FontSize> fontData;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.settings_view);
    TextView tv = (TextView) findViewById(R.id.font_size_opt);
    Typeface tf = TsciiTypeface.getTypeface(this);
    tv.setTypeface(tf);

    tv.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            showPopupMenu();

        }
    });

    SharedPreferences sp = PreferenceManager
            .getDefaultSharedPreferences(this);
    currentFontSize = Integer.parseInt(sp.getString("font_size", "1"));
    SharedPreferences.Editor editor = sp.edit();
    editor.clear();
    editor.commit();
}

private void showPopupMenu() {
    try {
        popup = new PopupWindow(this);
        LayoutInflater inflater = (LayoutInflater) this
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        popupView = inflater.inflate(R.layout.font_popup_view, null, false);


        fontSizeListView = (ListView) popupView
                .findViewById(R.id.font_size_list);

        String[] arrLabel = getResources().getStringArray(
                R.array.font_size_label_array);
        String[] arrValue = getResources().getStringArray(
                R.array.font_size_value_array);

        fontData = new Vector<FontSize>();
        for (int i = 0; i < arrLabel.length; i++) {
            fontData.add(new FontSize(Integer.parseInt(arrValue[i]), arrLabel[i]));
        }

        CustomAdapter adapter = new CustomAdapter(this, R.layout.custom_list_pref_row, fontData);
        fontSizeListView.setAdapter(adapter);
        popup.setContentView(popupView);
        popup.showAtLocation(this.findViewById(R.id.font_size_opt), Gravity.CENTER, 0, 0); 

         adapter.notifyDataSetChanged();

    } catch (Exception e) {
        MessageBox(e.toString());
    }

}

private View getRowView(String label, int value,ViewGroup parent) {
    try {
        LayoutInflater inflater = (LayoutInflater) this
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View row = inflater.inflate(R.layout.custom_list_pref_row, parent,false);
        TextView text = (TextView) row
                .findViewById(R.id.custom_list_view_row_text_view);
        text.setText(label);
        RadioButton rButton = (RadioButton) row
                .findViewById(R.id.custom_list_view_row_radio_button);
        rButton.setId(value);
        row.setTag(value);
        row.setClickable(true);

        if (value == currentFontSize) {
            rButton.setChecked(true);
        }

        row.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {

            }
        });

        return row;
    } catch (Exception e) {
        MessageBox(e.toString());
        return null;
    }


}

public void MessageBox(String message) {
    AlertDialog.Builder adb = new AlertDialog.Builder(this);
    adb.setTitle("Error");
    adb.setMessage(message);
    adb.setPositiveButton("Ok", null);
    adb.show();
}

class CustomAdapter extends ArrayAdapter<FontSize> {

    public CustomAdapter(Context context, int resource, List<FontSize> objects) {
        super(context, resource, objects);

    }

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

        // widgets displayed by each item in your list

        FontSize rowData = getItem(position);

        if (null == convertView) {
            convertView = getRowView(rowData.label,rowData.value,parent);

        }
        return convertView;
    }
}

private class FontSize {
    public int value;
        public String label;

        FontSize(int pvalue, String plabel){
            value = pvalue;
            label = plabel;             
    }

        @Override
        public String toString() {
                return value + " " +  label;
        }
}

}

This is the popup window layout xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 
android:id="@+id/popup_layout"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
xmlns:android="http://schemas.android.com/apk/res/android">
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="demo value"
 />
<ListView 
    android:layout_height="wrap_content"
    android:id="@+id/font_size_list"
    android:layout_width="wrap_content"></ListView>
 </LinearLayout>

回答1:

I had the same problem and calling update fixed the problem. I suspect that the width and height of the popup are not yet known. So in your case the code would be:

  popup.showAtLocation(this.findViewById(R.id.font_size_opt), Gravity.CENTER, 0, 0);
  popup.update(0, 0, popup_width, popup_height);

回答2:

I went along with a tutorial found here. I think I found what your problem is. In your View:

popupView = inflater.inflate(R.layout.font_popup_view, null, false);

You are returning a null value and false. Not sure what the false is, but instead of null try doing a ViewGroup:

popupView = inflater.inflate(R.layout.font_popup_view,
(ViewGroup) findViewById(R.id.popup_layout));

Hope this works for you.