タイトルとメッセージ、コールバックを設定できるダイアログ

CallbackDialogFragment.java

import android.app.AlertDialog;
import android.app.Dialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.DialogFragment;

/**
 * Created by ry0watana6e on 2015/10/19.
 */
public class CallbackDialogFragment extends DialogFragment {

    private String title;
    private String message;
    private OnCallbackListener mCallback;

    public interface OnCallbackListener {
        void onClickPositive();
        void onClickNegative();
    }


    public static CallbackDialogFragment newInstance(String title, String message) {
        Bundle args = new Bundle();
        args.putString("title", title);
        args.putString("message" , message);
        CallbackDialogFragment fragment = new CallbackDialogFragment();
        fragment.setArguments(args);
        return fragment;
    }

    public void setCallbackListenr(OnCallbackListener _callback){
        mCallback = _callback;
    }

    @NonNull
    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {

        if(getArguments() != null){
            title = getArguments().getString("title");
            message = getArguments().getString("message");
        }

        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        if(isExist(title))
            builder.setTitle(title);
        if(isExist(message))
            builder.setMessage(message);
        builder.setPositiveButton("はい", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                if(null != mCallback)
                    mCallback.onClickPositive();
            }
        });
        builder.setNegativeButton("いいえ", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                if(null != mCallback)
                    mCallback.onClickNegative();
            }
        });
        return builder.create();
    }

    private boolean isExist(String val) {
        if(val == null) return false;
        if(val.length() == 0) return false;
        return true;
    }
}