不要在onRestoreInstanceState上运行函数

Question

I am working on an app that when you go to a screen you select your location from a dialog which is created within onCreate . Once the location is selected it writes it into a predined TextView . A problem that I am having is when the screen orientation changes it recreates the dialog and I'm trying to have it not fire the dialog function.

Here is the basics of what I have within the class file.

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.emergpolice);

    form_location = (TextView) findViewById(R.id.input_location);

    if(form_location == null || form_location.getText().equals("")){
        setLocation();
    }
}

@Override
protected void onSaveInstanceState(Bundle outState){
    super.onSaveInstanceState(outState);
    outState.putString("LOCATION", (String)form_location.getText());
}

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState){
    super.onRestoreInstanceState(savedInstanceState);
    form_location.setText(savedInstanceState.getString("LOCATION"));
}

public void setLocation(){
    db = new DatabaseHandler(this);
    db.open();
    final CharSequence[] locOpt = {getString(R.string.dialog_items_current_location),getString(R.string.dialog_items_home),getString(R.string.dialog_items_enter_manually)};
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setTitle(getString(R.string.header_choose_location));
    builder.setSingleChoiceItems(locOpt, -1, new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int item){
            if(locOpt[item].equals(getString(R.string.dialog_items_home))){
                Cursor cur = db.userInfo(); 
                String address = cur.getString(cur.getColumnIndex("address"));
                String city = cur.getString(7);
                String county = cur.getString(8);
                String state = cur.getString(9);
                String zip = cur.getString(10);
                db.close();
                form_location.setText(address + ", " + city + ", " + county + ", " + state + ", " + zip);
            }
            if(locOpt[item].equals(getString(R.string.dialog_items_current_location))){
                Toast.makeText(getApplicationContext(), locOpt[item], Toast.LENGTH_SHORT).show();
            }
            dialog.cancel();
        }
    });
    AlertDialog alert = builder.create();
    alert.show();
}

And the TextView in my layout is

        <TextView
            android:id="@+id/input_location"
            android:layout_width="wrap_content"
            android:layout_below="@+id/text_location"
            android:layout_height="wrap_content"
            android:text="" />

As far as firing setLocation() is have tried several scenarios to check the string length, whether null or not. When the screen changes it shows the original chosen location, but still fires the dialog.

Answer 1

You always call the method setLocation because each time the onCreate method of the Activity is called form_location.getText().equals("") will be true (because the TextView is recreated(and most likely you don't set text on it in the layout file)).

To avoid this, use the savedInstanceState of the onCreate method:

if (savedInstanceState == null){
   // if savedInstanceState is null the activity is created for the first time
   setLocation();
} else {
   // if not null then the activity is recreated so restore the TextView text
   form_location.setText(savedInstanceState.getString("LOCATION"));
}

Answer 2

You can set in the manifest file in the activity tag an attributed of configchange. If you set. The flag orientation than your activity will not be destroyed on every orientation change. So onceate will only be called once.