使用共享偏好来存储高分
问题描述：
它给我一个错误无法解析符号sharedpreferences，我试图给每次用户参加测验时添加一个高分，它记录测验的高分。我不知道发生了什么。请帮助我这个，我会帮助你与我们的声誉。使用共享偏好来存储高分
package com.example.quiz;
import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Build;
import android.os.Bundle;
import android.os.CountDownTimer;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.Random;
import java.util.concurrent.TimeUnit;
import java.util.logging.Handler;
public class CS_Assembly_Easy extends Activity{
TextView topscore;
public static final String mypreference = "mypref";
public static final String Topscore = "topKey";
ArrayList<Question> quesList;
ArrayList<Question> toSelectFrom; // <--- HERE
int score = 0;
int qid = 0;
int lives = 5;
int round = 1;
int timer;
Question currentQ;
TextView txtQuestion, times, scored, livess, rounds;
Button button1, button2, button3;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.cs_assembly_easy);
CS_Assembly_QuizHelper db = new CS_Assembly_QuizHelper(this); // my question bank class
quesList = db.getAllQuestions();
toSelectFrom = new ArrayList<Question>(); // <--- HERE
toSelectFrom.addAll(quesList); // <--- HERE
Random random = new Random();// this will fetch all quetonall questions
currentQ = toSelectFrom.get(random.nextInt(toSelectFrom.size())); // the current question <-- edited here too.
toSelectFrom.remove(toSelectFrom.indexOf(currentQ)); // <--- HERE
txtQuestion = (TextView) findViewById(R.id.txtQuestion);
// the textview in which the question will be displayed
// the three buttons,
// the idea is to set the text of three buttons with the options from question bank
button1 = (Button) findViewById(R.id.button1);
button2 = (Button) findViewById(R.id.button2);
button3 = (Button) findViewById(R.id.button3);
// the textview in which will be displayed
scored = (TextView) findViewById(R.id.score);
// the timer
times = (TextView) findViewById(R.id.timers);
rounds = (TextView) findViewById(R.id.round);
// method which will set the things up for our game
setQuestionView();
times.setText("00:02:00");
// A timer of 60 seconds to play for, with an interval of 1 second (1000 milliseconds)
CounterClass timer = new CounterClass(60000, 1000);
timer.start();
// button click listeners
button1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// passing the button text to other method
// to check whether the anser is correct or not
// same for all three buttons
getAnswer(button1.getText().toString());
}
});
button2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
getAnswer(button2.getText().toString());
}
});
button3.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
getAnswer(button3.getText().toString());
}
});
topscore = (TextView) findViewById(R.id.Topscore);
sharedpreferences = getSharedPreferences(mypreference,
Context.MODE_PRIVATE);
if (sharedpreferences.contains(topscore) > score) {
topscore.setText(sharedpreferences.getString(topscore, ""));
}
}
public void Save(View view) {
String n = topscore.getText().toString();
SharedPreferences.Editor editor = sharedpreferences.edit();
editor.putString(Topscore, n);
editor.commit();
}
public void clear(View view) {
topscore = (TextView) findViewById(R.id.Topscore);
topscore.setText("");
}
public void Get(View view) {
topscore = (TextView) findViewById(R.id.Topscore);
sharedpreferences = getSharedPreferences(mypreference,
Context.MODE_PRIVATE);
if (sharedpreferences.contains(topscore)) {
topscore.setText(sharedpreferences.getString(topscore, ""));
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public void getAnswer(String AnswerString) {
if (currentQ.getANSWER().equals(AnswerString)) {
// if conditions matches increase the int (score) by 1
// and set the text of the score view
score++;
scored.setText(" Score : " + score);
LayoutInflater inflater = getLayoutInflater();
// Inflate the Layout
View layout = inflater.inflate(R.layout.correct,
(ViewGroup) findViewById(R.id.custom_toast_layout));
TextView text = (TextView) layout.findViewById(R.id.textToShow);
// Set the Text to show in TextView
text.setText("CORRECT");
text.setTextSize(25);
Toast toast = new Toast(getApplicationContext());
toast.setGravity(Gravity.BOTTOM, 0, 50);
toast.setDuration(Toast.LENGTH_SHORT);
toast.setView(layout);
toast.show();
} else if(lives > -10){
LayoutInflater inflater = getLayoutInflater();
// Inflate the Layout
View layout = inflater.inflate(R.layout.wrong,
(ViewGroup) findViewById(R.id.custom_toast_layout));
TextView text = (TextView) layout.findViewById(R.id.textToShow);
// Set the Text to show in TextView
text.setText("WRONG");
text.setTextSize(25);
Toast toast = new Toast(getApplicationContext());
toast.setGravity(Gravity.BOTTOM, 0, 50);
toast.setDuration(Toast.LENGTH_SHORT);
toast.setView(layout);
toast.show();
}
else {
Intent intent = new Intent(CS_Assembly_Easy.this,
ResultActivity_Assembly_Easy.class);
Bundle b = new Bundle();
b.putInt("score", score); // Your score
intent.putExtras(b); // Put your score to your next
startActivity(intent);
finish();
}
{
}
if (qid < 10) {
// if questions are not over then do this
Random random = new Random();
currentQ = toSelectFrom.get(random.nextInt(toSelectFrom.size())); // <<--- HERE
toSelectFrom.remove(toSelectFrom.indexOf(currentQ)); // <<--- AND HERE
setQuestionView();
round++;
rounds.setText(" Question:" + round + "/10");
} else {
// if over do this
Intent intent = new Intent(CS_Assembly_Easy.this,
ResultActivity_Assembly_Easy.class);
Bundle b = new Bundle();
b.putInt("score", score); // Your score
intent.putExtras(b); // Put your score to your next
startActivity(intent);
finish();
}
}
@TargetApi(Build.VERSION_CODES.GINGERBREAD)
@SuppressLint("NewApi")
public class CounterClass extends CountDownTimer {
public CounterClass(long millisInFuture, long countDownInterval) {
super(millisInFuture, countDownInterval);
// TODO Auto-generated constructor stub
}
@Override
public void onFinish() {
times.setText("Time is up");
}
@Override
public void onTick(long millisUntilFinished) {
// TODO Auto-generated method stub
long millis = millisUntilFinished;
String hms = String.format(
"%02d:%02d:%02d",
TimeUnit.MILLISECONDS.toHours(millis),
TimeUnit.MILLISECONDS.toMinutes(millis)
- TimeUnit.HOURS.toMinutes(TimeUnit.MILLISECONDS
.toHours(millis)),
TimeUnit.MILLISECONDS.toSeconds(millis)
- TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS
.toMinutes(millis)));
System.out.println(hms);
times.setText(hms);
}
}
private void setQuestionView() {
// the method which will put all things together
txtQuestion.setText(currentQ.getQUESTION());
button1.setText(currentQ.getOPTA());
button2.setText(currentQ.getOPTB());
button3.setText(currentQ.getOPTC());
qid++;
}
@Override
public void onBackPressed() {
return;
}
}
答
sharedpreferences未在您的CS_Assembly_Easy类中定义。
尝试将您的代码更改为：
SharedPreferences sharedpreferences = getSharedPreferences(mypreference,
Context.MODE_PRIVATE);