评分栏Android

Question

Hi I am busy making a program where you get to rate people I've been playing around with the Rating Bar widget however I am struggling to make it show a rating after selecting the amount of stars. What I'm I doing wrong. I would also like to to know if the android sdk have anything on up and down votes and would it be wise to use images for a rating system.

The reason why some of the code is commented out is because my app won't run when its uncommented but I know its needed to do what I want to do.

import android.app.Activity;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.RatingBar;
import android.widget.RatingBar.OnRatingBarChangeListener;
import android.widget.TextView;
public class rating_system_fragment extends Fragment implements OnRatingBarChangeListener{

RatingBar ratingBar;
TextView ratingResult;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    inflater.inflate(R.layout.rating_system_fragment,container,false);
    //setContentView(R.layout.activity_main);
    return inflater.inflate(R.layout.rating_system_fragment, container, false);
    //ratingResult = (TextView) ratingResult.findViewById(R.id.textViewRating);
    //((RatingBar) ratingBar.findViewById(R.id.ratingBar))
      //      .setOnRatingBarChangeListener(this);
}

@Override
public void onRatingChanged(RatingBar ratingBar, float rating,
                            boolean fromTouch) {
    final int numStars = ratingBar.getNumStars();
    ratingResult.setText(rating + "/" + numStars);
}

}

Answer 1

You have several syntax erros in your commented code. It should look like this:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    View rootView = inflater.inflate(R.layout.rating_system_fragment,container,false);
    ratingResult = (TextView) rootView.findViewById(R.id.textViewRating);
    ratingBar = (RatingBar) rootView.findViewById(R.id.ratingBar);
    ratingBar.setOnRatingBarChangeListener(this);

    return rootView;
}

The key here is that ratingBar and textViewRating are childs of your root view, and should only be accessed when you have aready inflated them.