1.可自定義一個這樣的WeakReferenceHandler

public class WeakReferenceHandler<T> extends Handler {

    private final WeakReference<T> mReference;

    public WeakReferenceHandler(T referencedObject) {
        mReference = new WeakReference<>(referencedObject);
    }

    public WeakReferenceHandler(Looper looper, T referencedObject) {
        super(looper);
        mReference = new WeakReference<>(referencedObject);
    }

    protected T getReferencedObject() {
        return mReference.get();
    }

}
 

2.在Fragment建立一個新Handler並繼承WeakReferenceHandler

private RangHandler mHandler;

/**
 * 處理非同步操作
 */
private static class RangHandler extends WeakReferenceHandler<RankingFragment> {

    public RangHandler(RankingFragment referencedObject) {
        super(referencedObject);
        // TODO Auto-generated constructor stub
    }

//編寫自己的需要執行的任務
    @Override
    public void handleMessage(Message msg) {
        RankFragment fragment = getReferencedObject();
        if (fragment != null && fragment.getActivity() != null) {
            switch (msg.what) {
                case MSG_SHOW:
                    fragment.refreshed();
                    if (fragment.mRankDataAdapter != null) {
                        fragment.mRankDataAdapter.notifyDataSetChanged();
                    }
                    break;
                case MSG_ERROR:
                    if (fragment.isAdded())
                        Toast.makeText(fragment.getActivity(), R.string.error_response, Toast.LENGTH_SHORT).show();
                    fragment.refreshedFail();
                    break;
                default:
                    if (fragment.isAdded())
                        Toast.makeText(fragment.getActivity(), R.string.error_response, Toast.LENGTH_SHORT).show();
                    break;
            }
        }
    }
}
 

3.在onCreateView方法中例項化Handler

mHandler = new RangHandler(this);

4.需要呼叫的地方時

mHandler.sendEmptyMessage(MSG_SHOW);