我想在SharedPreferences中保护一个int，但是当我使用Editor时，我的程序总是崩溃。如果我使用调试工具，它说pref和prefEditor总是为null而highscore为0.我希望有人可以帮助我。这是我的代码：
package ordicolor.ordicolor;
import android.app.Activity;
import android.content.Context;
import android.content.SharedPreferences;
import android.content.res.Resources;
import android.os.Bundle;
public class MainActivity extends Activity {
int highscore;
SharedPreferences pref;
SharedPreferences.Editor prefEditor;
public MainActivity(){
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(new GameView(this));
pref = this.getSharedPreferences("high", Context.MODE_PRIVATE);
highscore = pref.getInt("high",10);
}
public static int getScreenWidth() {
return Resources.getSystem().getDisplayMetrics().widthPixels;
}
public static int getScreenHeight() {
return Resources.getSystem().getDisplayMetrics().heightPixels;
}
@Override
protected void onStop(){
super.onStop();
}
public void setHighscore(int pHigh){
highscore = pHigh;
}
public int getHighscore(){
return highscore;
}
public void safe(){
pref = getSharedPreferences("high", Context.MODE_PRIVATE);
prefEditor = pref.edit(); //Here must be the mistake.
prefEditor.putInt("high",this.getHighscore());
prefEditor.commit();
}
}package ordicolor.ordicolor;
import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import java.util.Random;
import static java.lang.String.valueOf;
public class GameView extends SurfaceView {
private SurfaceHolder surfaceHolder;
MainActivity main = new MainActivity();
private Bitmap bmp1, bmp2 ,bmp3 ,bmp4 ,bmp5 ,bmp6 ,bmp7 ,bmp8;
private Bitmap licht;
private int y;
private int direction, fortschritt, tlinks, trechts, rZaehler, blinken, etagenHoehe, etage, gefahren, rndEtage, zeitzaehler, rectBreite, cdGeschwindigkeit, screenW ,screenH, sollFahren, score, restartZaehler, btnGroesse, highscore;
private GameLoopThread theGameLoopThread;
private Sprite theSprite, theSprite2, theSprite3, theSprite4;
private boolean amfahren, schaden, hoch, runter, fuellen, gameOver, speichern;
Random rnd = new Random();
Paint paint = new Paint();
@SuppressLint("WrongCall") public GameView(Context context) {
super(context);
surfaceHolder = getHolder();
surfaceHolder.addCallback(new SurfaceHolder.Callback() {
public void surfaceDestroyed(SurfaceHolder holder) {
boolean retry = true;
theGameLoopThread.setRunning(false);
while(retry){
try {
theGameLoopThread.join();
retry=false;
}catch(InterruptedException e){
}
}
}
public void surfaceCreated(SurfaceHolder holder) {
theGameLoopThread.setRunning(true);
theGameLoopThread.start();
}
public void surfaceChanged(SurfaceHolder holder, int format,int width, int height) {
}
});
direction = 0;
fortschritt = 0;
tlinks = 0;
trechts = 0;
rZaehler = 0;
blinken = 0;
etagenHoehe = 0;
etage = 0;
gefahren = 0;
rndEtage= 0;
zeitzaehler = 0;
rectBreite= 0;
cdGeschwindigkeit = 0;
screenW = 0;
screenH = 0;
sollFahren = 0;
score = 0;
amfahren = false;
schaden = false;
hoch = false;
runter = false;
fuellen = false;
gameOver = false;
speichern = false;
screenW = main.getScreenWidth();
screenH = main.getScreenHeight();
btnGroesse = screenH / 6;
bmp1 = BitmapFactory.decodeResource(getResources(),R.drawable.fahrstuhl,null);
bmp1 = Bitmap.createScaledBitmap(bmp1,screenW, screenH * 8,true);
etagenHoehe = bmp1.getHeight() / 8;
gefahren = 0;
bmp2 = BitmapFactory.decodeResource(getResources(),R.drawable.innen,null);
bmp2 = Bitmap.createScaledBitmap(bmp2, screenW, screenH,true);
bmp3 = BitmapFactory.decodeResource(getResources(),R.drawable.plus,null);
bmp3 = Bitmap.createScaledBitmap(bmp3, btnGroesse, btnGroesse,true);
bmp4 = BitmapFactory.decodeResource(getResources(),R.drawable.minus,null);
bmp4 = Bitmap.createScaledBitmap(bmp4, btnGroesse, btnGroesse,true);
bmp5 = BitmapFactory.decodeResource(getResources(),R.drawable.tuerlinks,null);
bmp5 = Bitmap.createScaledBitmap(bmp5, screenW / 2, screenH,true);
bmp6 = BitmapFactory.decodeResource(getResources(),R.drawable.tuerrechts,null);
bmp6 = Bitmap.createScaledBitmap(bmp6, screenW / 2, screenH,true);
bmp7 = BitmapFactory.decodeResource(getResources(),R.drawable.reparieren,null);
bmp7 = Bitmap.createScaledBitmap(bmp7, btnGroesse, btnGroesse,true);
bmp8 = BitmapFactory.decodeResource(getResources(),R.drawable.ordicolorgameover,null);
bmp8 = Bitmap.createScaledBitmap(bmp8, screenW, screenH,true);
licht = BitmapFactory.decodeResource(getResources(),R.drawable.lichtzwei,null);
trechts = bmp2.getWidth();
tlinks = -bmp2.getWidth() / 2;
theSprite = new Sprite(this, bmp3, 0, screenH - btnGroesse);
theSprite2 = new Sprite(this, bmp4, screenW - btnGroesse , screenH - btnGroesse);
theSprite3 = new Sprite(this, bmp7, (screenW/2)-(btnGroesse/2) , screenH - btnGroesse);
theSprite4 = new Sprite(this, bmp8, 0, 0);
theGameLoopThread = new GameLoopThread(this);
rndEtage();
paint.setTextSize(50);
y = -etagenHoehe *7;
}
@Override
protected void onDraw(Canvas canvas) {
if(!gameOver){
paint.setColor(Color.BLACK);
canvas.drawBitmap(bmp1, 0, y, null);
canvas.drawBitmap(bmp5,tlinks ,0, null);
canvas.drawBitmap(bmp6,trechts ,0, null);
canvas.drawBitmap(bmp2, 0, 0, null);
canvas.drawBitmap(licht, 0, 0,null);
theSprite.onDraw(canvas);
theSprite2.onDraw(canvas);
if(schaden){theSprite3.onDraw(canvas);}
canvas.drawText(valueOf(etage),bmp2.getWidth() / 2 - 12, 68, paint);
canvas.drawText(valueOf(rndEtage),bmp2.getWidth()- 80, bmp2.getHeight() / 2 + 19, paint);
paint.setColor(Color.GREEN);
canvas.drawRect(0 ,0 ,rectBreite,10,paint);
}
else{
paint.setColor(Color.WHITE);
canvas.drawRect(0 ,0 ,screenW,screenH,paint);
paint.setColor(Color.RED);
paint.setTextSize(100);
canvas.drawText("Game Over",100, screenH/4, paint);
paint.setColor(Color.BLACK);
canvas.drawText("Score: " + valueOf(score), 100, screenH/4*2, paint);
canvas.drawText("Highscore: " + valueOf(main.getHighscore()), 100, screenH/8*7, paint);
theSprite4.onDraw(canvas);
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
synchronized (getHolder()) {
if (theSprite.isTouched(event.getX(), event.getY()) && etage < 7 && !runter) {
direction = 30;
gefahren = 0;
etage++;
fortschritt = 0;
amfahren = true;
hoch = true;
fuellen = true;
sollFahren += 1;
}
if (theSprite2.isTouched(event.getX(), event.getY()) && etage > 0 && !hoch) {
direction = -30;
gefahren = 0;
etage--;
fortschritt = 0;
amfahren = true;
runter = true;
fuellen = true;
sollFahren += 1;
}
if (theSprite3.isTouched(event.getX(), event.getY())) {
rZaehler++;
}
if (theSprite4.isTouched(event.getX(), event.getY()) && gameOver && restartZaehler >= 150) {
gameOver = false;
rectBreite = 0;
paint.setTextSize(50);
y = -etagenHoehe * 7;
etage = 0;
score = 1;
schaden = false;
cdGeschwindigkeit = 0;
restartZaehler = 0;
sollFahren = 0;
licht = BitmapFactory.decodeResource(getResources(),R.drawable.lichtzwei,null);
main.safe();
}
}
return false;
}
//Testet, ob der Fahrstuhl die gewünschte Etage errreicht hat und hält ihn an.
public void fahren(){
if(amfahren){
if(fortschritt == 0){
schliessen();
}
if(fortschritt == 1){
schaden();
}
if(fortschritt == 2){
bewegen();
}
if(fortschritt == 3){
oeffnen();
}
}
else{
rndEtage();
}
if(gameOver){
restartZaehler++;
}
}
//schließt die Tür
public void schliessen(){
if(tlinks < 0){
tlinks += 20;
trechts -= 20;
}
else{
tlinks += 4;
trechts -= 4;
fortschritt = 1;
runter = true;
hoch = true;
}
}
//Steuert den Schaden des Aufzugs.
public void schaden(){
if(!schaden){
if(rnd.nextInt(4 - -1) == 1){
schaden = true;
rZaehler = 0;
}
else{
fortschritt = 2;
}
}
else{
blinken++;
fuellen = false;
if(10 <= rZaehler){
schaden = false;
fortschritt = 2;
licht = BitmapFactory.decodeResource(getResources(),R.drawable.lichtzwei,null);
}
if(blinken ==10){
licht = BitmapFactory.decodeResource(getResources(),R.drawable.lichtzwei,null);
}
if(blinken ==20){
licht = BitmapFactory.decodeResource(getResources(),R.drawable.licht,null);
licht = Bitmap.createScaledBitmap(licht, screenW, screenH,true);
blinken = 0;
}
}
}
//Bewegt den Aufzug.
public void bewegen(){
fuellen = true;
if(direction != 0){
y += direction;
gefahren += 30;
}
if(gefahren >= etagenHoehe * sollFahren) {
direction = 0;
fortschritt = 3;
tlinks -= 4;
trechts += 4;
sollFahren = 0;
}
}
//Öffnet die Tür.
public void oeffnen(){
if(tlinks > -600){
tlinks -= 20;
trechts += 20;
}
else{
amfahren = false;
fortschritt = 0;
runter = false;
hoch = false;
fuellen = false;
}
}
public void rndEtage(){
if(etage == rndEtage && !gameOver) {
rndEtage = rnd.nextInt(7 - -1);
rectBreite = 0;
cdGeschwindigkeit++;
score++;
}
}
//Hier wird die Zeit, die der Spieler zum drücken hat verwaltet.
public void zeit(){
if(!fuellen){
if(zeitzaehler >= 10){
rectBreite +=30;
zeitzaehler = cdGeschwindigkeit;
}
else{
zeitzaehler++;
}
if(rectBreite >= screenW){
fortschritt = 3;
gameOver = true;
if(main.getHighscore() < score){
main.setHighscore(highscore);
}
}
}
}
}