android釋放記憶體的一個辦法

step 1:定義一個監聽介面

public static interface OnLowMemoryListener {  
        void onLowMemoryReceived();  
    }  /* 何問起 hovertree.com */

step 2:android application文件中添加如下代碼

//初始化

private ArrayList<WeakReference<OnLowMemoryListener>> mLowMemoryListeners;  
/* 何問起 hovertree.com */

public MyApp() {  
        mLowMemoryListeners = new ArrayList<WeakReference<OnLowMemoryListener>>();  
    }  /* 何問起 hovertree.com */

//註冊監聽

public void registerOnLowMemoryListener(OnLowMemoryListener listener) {  
        if (listener != null) {  
            mLowMemoryListeners  
                    .add(new WeakReference<MyApp.OnLowMemoryListener>(listener));  
        }  
    }  
//移除監聽  
    public void unregisterOnLowMemoryListener(OnLowMemoryListener listener) {  
        if (listener != null) {  
            int i = 0;  
            while (i < mLowMemoryListeners.size()) {  
                final OnLowMemoryListener l = mLowMemoryListeners.get(i).get();  
                if (l == null || l == listener) {  
                    mLowMemoryListeners.remove(i);  
                } else {  
                    i++;  
                }  
            }  
        }  
    }  /* 何問起 hovertree.com */

//記憶體空間過低的時候，被系統調用

@Override  
    public void onLowMemory() {  
        super.onLowMemory();  
        int i = 0;  
        while (i < mLowMemoryListeners.size()) {  
            final OnLowMemoryListener l = mLowMemoryListeners.get(i).get();  
            if (l == null) {  
                mLowMemoryListeners.remove(i);  
            } else {  
                l.onLowMemoryReceived();  
                i++;  
            }  
        }  
    }  /* 何問起 hovertree.com */

step 3：那些浪費記憶體的地方，比如圖片緩存，可以實現並註冊這個監聽

推薦:http://www.cnblogs.com/roucheng/p/androidtuichu.html