在第一次启动应用程序时，我想提示用户（通过对话框）选择他们的城市，然后保存他们的偏好并将适当的数据加载到列表视图中。但是，我注意到一个对话框可以通过后退按钮关闭，或者在对话框之外的任何地方按下，然后触发数据库的空值。
无论如何我可以强制对话框保持打开状态，直到用户选择一个选项？
我已经实现了.setCancelable(false)，这似乎不起作用。我的代码在下面，DialogSetup是我正在使用的内部类。
任何帮助/想法将不胜感激。
public class MainActivity extends ListActivity {
private Cursor lines;
private MetroSleepDb db;
private ListAdapter adapter;
public static final String PREFS_NAME = "METROSLEEP_PREFS";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
chooseCityDialog();
}
public void setAdapters() {
db = new MetroSleepDb(this);
lines = db.getLines(); // you would not typically call this on the main thread
//ListView listView = (ListView) findViewById(R.id.li);
adapter = new SimpleCursorAdapter(this, android.R.layout.simple_list_item_1,
lines,
new String[] {"line_id"},
new int[] {android.R.id.text1}, 0);
getListView().setAdapter(adapter);
getListView().setOnItemClickListener(onAnswerClicked);
}
public String getItem(int pos) {
Cursor c = (Cursor) adapter.getItem(pos);
String value = c.getString(c.getColumnIndex("line_id"));
return value;
}
private OnItemClickListener onAnswerClicked = new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
String line_value = getItem(position);
Intent intent = new Intent(MainActivity.this, ChooseStations.class);
intent.putExtra("line", line_value);
startActivity(intent);
}
};
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
// This ID represents the Home or Up button. In the case of this
// activity, the Up button is shown. Use NavUtils to allow users
// to navigate up one level in the application structure. For
// more details, see the Navigation pattern on Android Design:
//
// http://developer.android.com/design/patterns/navigation.html#up-vs-back
//
NavUtils.navigateUpFromSameTask(this);
return true;
case R.id.menu_settings:
Intent intent = new Intent(this, SettingsActivity.class);
startActivity(intent);
return true;
}
return super.onOptionsItemSelected(item);
}
public void chooseCityDialog() {
DialogFragment newFragment = new DialogSetup();
newFragment.show(getFragmentManager(), "citypref");
}
public static final class DialogSetup extends DialogFragment {
public Dialog onCreateDialog(Bundle savedInstanceState) {
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
builder.setTitle(R.string.prompt_choose_city)
.setCancelable(false)
.setItems(R.array.Cities, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
//
}
});
return builder.create();
}
}
}