1

我一直在阅读 Observer Pattern 以使我的 UI 保持最新，但我仍然无法让它工作，据我所知，Observer 是我的 UI，它会监视我的 Pet 类是否有任何变量变化是否运行 update()；目前它什么都不做，甚至 Log.d 也没有。

观察者/MainActivity

package com.grim.droidchi;

import java.util.Observable;
import java.util.Observer;

import android.app.Activity;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.webkit.WebSettings.LayoutAlgorithm;
import android.webkit.WebView;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity implements Observer, OnClickListener {
    private static final String TAG = "VPET";
    private static final String APP_PREFS = "VPET";
    private static final int REQUEST_CODE = 1;

    TextView happiness_display, health_display, hunger_display, level_display;
    Button PunchPet, UpdateHunger;
    public static Pet pet = new Renamon();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        WebView myWebView = (WebView) findViewById(R.id.pet_display);
        myWebView.loadUrl("file:///android_asset/renamon.gif");
        myWebView.setInitialScale(10000);
        myWebView.getSettings().setLayoutAlgorithm(LayoutAlgorithm.SINGLE_COLUMN);


        PunchPet = (Button) findViewById(R.id.PunchPet);
        UpdateHunger = (Button) findViewById(R.id.UpdateHunger);
        final TextView hunger_display = (TextView) findViewById(R.id.hunger_display);
        TextView happiness_display = (TextView) findViewById(R.id.happiness_display);
        TextView level_display = (TextView) findViewById(R.id.level_display);
        TextView health_display = (TextView) findViewById(R.id.health_display);

        hunger_display.setText(Integer.toString(pet.getHunger()));
        health_display.setText(Integer.toString(pet.getHP()));
        level_display.setText(Integer.toString(pet.getLVL()));
        happiness_display.setText(Integer.toString(pet.getHappy()));


        Intent intent = new Intent(this, Gameloop.class);
        PendingIntent pendingIntent = PendingIntent.getBroadcast(
                getBaseContext(), REQUEST_CODE, intent, 0);

        AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
        alarmManager.setRepeating(AlarmManager.RTC_WAKEUP,
                System.currentTimeMillis() + (5 * 1000), 1800000, pendingIntent);
        // 1800000 ms = 30 mins

        pet.feed();
        pet.addObserver(this);
        pet.notifyObservers(pet);


    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }

    @Override
    protected void onPause() {


        super.onPause();
    }

    @Override
    public void update(Observable o, Object data) {
        Toast.makeText(getApplicationContext(), "soemthing has changed", Toast.LENGTH_LONG).show();
    }

    @Override
    public void onClick(View v) {
        if (v == PunchPet) {
            pet.setLVL(50);
            pet.notifyObservers(pet);
            Log.d(TAG, "PUNCHPET" + pet.getHP());

    }else {

    }



    }

}

可观察/宠物

package com.grim.droidchi;

import java.util.Observable;


import android.util.Log;

public class Pet extends Observable implements PetInterface {

    private static final String TAG = "VPET";
    private int Health = 100;

    private int Happiness = 10;
    private int Level = 1;
    private int Hunger = 0;
    private int Exp = 0;
    private String Name;
    private Boolean isAlive = true;
    private Boolean isSick = false;

    public void setisAlive(boolean answer) {
        this.isAlive = answer;
    }

    public void setisSick(boolean answer) {
        this.isAlive = answer;
    }

    public void setHP(int hp) {
        this.Health = hp;
        notifyObservers(hp);
    }

    public void setLVL(int lvl) {
        this.Level = lvl;
        notifyObservers(lvl);
    }

    public void setXP(int xp) {
        this.Exp = xp;
        notifyObservers(xp);
    }

    public void setHunger(int hunger) {
        this.Hunger = hunger;
        notifyObservers(hunger);
    }

    public void setHappy(int happy) {
        this.Happiness = happy;
        notifyObservers(happy);
    }

    public int getHP() {

        return Health;
    }

    public int getLVL() {

        return Level;
    }

    public int getXP() {

        return Exp;
    }

    public int getHunger() {

        return Hunger;
    }

    public int getHappy() {

        return Happiness;
    }

    public boolean isAlive() {
        return isAlive;

    }

    public boolean isSick() {
        return isSick;

    }

    @Override
    public void sleep() {
        // TODO Auto-generated method stub

    }

    @Override
    public void clean() {
        // TODO Auto-generated method stub

    }

    @Override
    public void feed() {
        Log.d(TAG, "FEEDING FROM INTERFACE THING");

    }

    @Override
    public void passtime() {

    }

}

是的，我也问过这个问题，但如您所知，它有两个答案（尽管它们可能是对的但对我没有帮助）并且现在不再收到它会在列表中掉得太远，如果我可以删除我会的

日志猫

02-25 22:51:50.381: E/AndroidRuntime(12026): FATAL EXCEPTION: main
02-25 22:51:50.381: E/AndroidRuntime(12026): java.lang.NullPointerException
02-25 22:51:50.381: E/AndroidRuntime(12026):    at com.grim.droidchi.MainActivity.update(MainActivity.java:93)
02-25 22:51:50.381: E/AndroidRuntime(12026):    at java.util.Observable.notifyObservers(Observable.java:138)
02-25 22:51:50.381: E/AndroidRuntime(12026):    at com.grim.droidchi.Pet.setHP(Pet.java:33)
02-25 22:51:50.381: E/AndroidRuntime(12026):    at com.grim.droidchi.MainActivity$1.onClick(MainActivity.java:47)
02-25 22:51:50.381: E/AndroidRuntime(12026):    at android.view.View.performClick(View.java:4202)
02-25 22:51:50.381: E/AndroidRuntime(12026):    at android.view.View$PerformClick.run(View.java:17340)
02-25 22:51:50.381: E/AndroidRuntime(12026):    at android.os.Handler.handleCallback(Handler.java:725)
02-25 22:51:50.381: E/AndroidRuntime(12026):    at android.os.Handler.dispatchMessage(Handler.java:92)
02-25 22:51:50.381: E/AndroidRuntime(12026):    at android.os.Looper.loop(Looper.java:137)
02-25 22:51:50.381: E/AndroidRuntime(12026):    at android.app.ActivityThread.main(ActivityThread.java:5191)
02-25 22:51:50.381: E/AndroidRuntime(12026):    at java.lang.reflect.Method.invokeNative(Native Method)
02-25 22:51:50.381: E/AndroidRuntime(12026):    at java.lang.reflect.Method.invoke(Method.java:511)
02-25 22:51:50.381: E/AndroidRuntime(12026):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795)
02-25 22:51:50.381: E/AndroidRuntime(12026):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562)
02-25 22:51:50.381: E/AndroidRuntime(12026):    at dalvik.system.NativeStart.main(Native Method)
4

2 回答 2

3

问题是您已经覆盖notifyObservers()，但没有notifyObservers(java.lang.Object)。您正在调用后者，但您没有定义它。

    @Override
    public void notifyObservers(Object o) {
        observers.notify(o);
        super.notifyObservers(o);
    }

此外，您可能会在内部更改这些值，但观察者不知道。调用setChanged()你的“宠物”（Observable）来解决这个问题。

于 2013-02-25T21:04:26.617 回答
3

当您从 继承时Observable，您的类将继承其所有功能。Observers除非您添加自己的功能，否则您不需要覆盖其方法或保留自己的 Set of 。如前所述Bailey S，在您的 setter 方法中，在call 之前notifyOservers()， call setChanged()。

尝试从类中删除您已覆盖的所有方法Observable。另外，每次打电话notifyObservers(object)，clearChanged()以后再打电话。

于 2013-02-25T21:45:47.967 回答