Question

我从SharedPreferences

成功加载了以下代码

List<MyObject> oList = new ArrayList<MyObject>();

// Get JSON Data from storage.
HashSet<String> oStrings = new HashSet<String>();
oStrings = (HashSet<String>) oSharedPrefs.getStringSet(IConstants.MY_OBJECT_LIST, null);

if (oStrings != null && oStrings.size() > 0)
{
  Gson oGson = new Gson();
  for (String strJSONObject : oStrings)
  {
    MyObject oObject = oGson.fromJson(strJSONObject, MyObject.class);
    oList.add(oObject);
  }
}

return oList;

问题是，这是在UI线程＆amp;随着SharedPreferences JSON字符串变大，这可能导致我的应用暂停几秒钟。

如何在后台加载此数据然后检索对象列表？

Answer 1

您可以使用AsyncTask：

public class LoadFromShared extends AsyncTask<Void, Void, List<MyObject>>{
  private OnLoadingDoneListener mListener;
  public interface OnLoadingDoneListener{
    public void onDone(List<MyObject> result);
  }

  public void setOnLoadingDoneListener(OnLoadingDoneListener listener){
    this.mListener = listener;
  }

  @Override
  protected List<MyObject> doInBackground(Void... params) {
    List<MyObject> oList = new ArrayList<MyObject>();
    // Get JSON Data from storage.
    HashSet<String> oStrings = new HashSet<String>();
    oStrings = (HashSet<String>) oSharedPrefs.getStringSet(IConstants.MY_OBJECT_LIST, null);
    if (oStrings != null && oStrings.size() > 0)
    {
      Gson oGson = new Gson();
      for (String strJSONObject : oStrings)
      {
        MyObject oObject = oGson.fromJson(strJSONObject, MyObject.class);
        oList.add(oObject);
      }
    }
    return oList;
  }

  protected void onPostExecute(List<MyObject> result) {
    if(mListener!=null={
      mListener.onDone(result);
    }
  };
}

然后在你的主要：

LoadFromShared loader = new LoadFromShared();
loader.setOnLoadingDoneListener(new OnLoadingDoneListener(){
  @Override
  onDone(List<MyObject> result){
    //do your stuff here
  }  
};);

loader.execute();

无法保证正确输入;）

来自后台的SharedPreferences的Android加载

1 个答案: