我有一个片段活动，想从我的PHP脚本中获取数据。我需要这些数据来有效地绘制我的ui。我的问题是我的UI /片段在我获取数据之前绘制，我不知道为什么我尽可能早地在onCreate'中解雇它。我在前后发布了一个对话框来有效地冻结UI，同时在后台检索数据但是......我没有看到这种情况发生，我认为在调试过程中出现对话框时调用它时为时已晚，它显示在绘制屏幕的顶部这让我感到困惑。
我有一个替代解决方案，即在调用活动（上一个活动）中触发asyncTask并将结果传递给bundle但我不喜欢这个解决方案，因为它很僵硬，可能会导致屏幕旋转问题。
我已经坚持了很多年，任何人都可以告诉我具体执行异步执行的位置 - 对话框应该有效地使其成为同步过程。我把我的asynctask放在任何地方，我认为可能/明智，没有运气。
在下面我有oncreate()中的执行。请注意，执行并不是任何事情，只是事先更新一个“无变化”的测试字符串，并在postexecute中“更改”，这样我就能看到它在代码中各个点的状态。在我绘制屏幕之前它没有改变。
public class StaggeredGridActivityFragment extends FragmentActivity {
String test ="not changed";
private TilesAdapter mAdapter;
private ArrayList<String> mData;
private StaggeredGridView mGridView;
private static final String TAG = "StaggeredGridActivityFragment";
@Override
protected void onCreate(Bundle savedInstanceState) {
try
{
// Loading tile data in Background Thread
new GetLoginTiles().execute();
}
catch (Exception e)
{
e.printStackTrace();
}
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE); //remove title bar
final FragmentManager fm = getSupportFragmentManager();
// Create the list fragment and add it as our sole content.
if (fm.findFragmentById(android.R.id.content) == null) {
final StaggeredGridFragment fragment = new StaggeredGridFragment();
fm.beginTransaction().add(android.R.id.content, fragment).commit();
}
Intent i=getIntent();
Bundle extras = i.getExtras();
String tmp = extras.getString("myKey");
}
private class StaggeredGridFragment extends Fragment implements AbsListView.OnScrollListener, AbsListView.OnItemClickListener {
//private StaggeredGridView mGridView;
private boolean mHasRequestedMore;
// private TilesAdapter mAdapter;
//private ArrayList<String> mData;
@Override
public void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setRetainInstance(true);
}
@Override
public View onCreateView(final LayoutInflater inflater, final ViewGroup container, final Bundle savedInstanceState) {
return inflater.inflate(R.layout.activity_sgv, container, false);
}
@Override
public void onActivityCreated(final Bundle savedInstanceState) {
List<NameValuePair> params = new ArrayList<NameValuePair>();
//Encapsulate all within a post cereate from a async task or call a blocking http call
super.onActivityCreated(savedInstanceState);
mGridView = (StaggeredGridView) getView().findViewById(R.id.grid_view);
if (savedInstanceState == null) {
final LayoutInflater layoutInflater = getActivity().getLayoutInflater();
View header = layoutInflater.inflate(R.layout.list_item_header_footer, null);
mGridView.addHeaderView(header);
}
if (mAdapter == null) {
mAdapter = new TilesAdapter(getActivity(), R.id.summary1_value);
}
if (mData == null) {
mData = ActivityTileData.getLoginTileDataArray(getActivity());
}
for (String data : mData) {
mAdapter.add(data); //Add each mData TileAdapter element to an mAdapter where it will be further broken down and used by the TileAdapter
}
mGridView.setAdapter(mAdapter);
mGridView.setOnScrollListener(this);
mGridView.setOnItemClickListener(this);
}
@SuppressLint("LongLogTag")
@Override
public void onScrollStateChanged(final AbsListView view, final int scrollState) {
Log.d(TAG, "onScrollStateChanged:" + scrollState);
}
@SuppressLint("LongLogTag")
@Override
public void onScroll(final AbsListView view, final int firstVisibleItem, final int visibleItemCount, final int totalItemCount) {
Log.d(TAG, "onScroll firstVisibleItem:" + firstVisibleItem +
" visibleItemCount:" + visibleItemCount +
" totalItemCount:" + totalItemCount);
// our handling
if (!mHasRequestedMore) {
int lastInScreen = firstVisibleItem + visibleItemCount;
if (lastInScreen >= totalItemCount) {
Log.d(TAG, "onScroll lastInScreen - so load more");
mHasRequestedMore = true;
onLoadMoreItems();
}
}
}
//Loads all of the objects from the getLoginTileData() if called
private void onLoadMoreItems() {
while(mAdapter.getCount()<mData.size()) {
//final ArrayList<String> sampleData = SampleData.generateSampleData();
final ArrayList<String> loginTileData = ActivityTileData.getLoginTileDataArray(getActivity());
for (String data : loginTileData) {
mAdapter.add(data.toString());
}
// stash all the data in our backing store
mData.addAll(loginTileData);
// notify the adapter that we can update now
mAdapter.notifyDataSetChanged();
mHasRequestedMore = false;
}
}
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int position, long id) {
Toast.makeText(getActivity(), "Item Clicked: " + position, Toast.LENGTH_SHORT).show();
}
}
// Progress Dialog
private ProgressDialog qDialog;
// JSON parser class
JSONParser jParser = new JSONParser();
String url_login ="http://xxx/xxx.php";
/**
* Background Async Task to Load all images by making HTTP Request
* */
class GetLoginTiles extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
qDialog = new ProgressDialog(StaggeredGridActivityFragment.this);
qDialog.setMessage("Please wait...");
qDialog.setIndeterminate(false);
qDialog.setCancelable(false);
qDialog.show();
}
@Override
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject jsonLogin = jParser.makeHttpRequest(url_login, "GET", params);
test=jsonLogin.toString();
return jsonLogin.toString();
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String jsonString) {
// dismiss the dialog after getting all questions
qDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into imagebuttons
* */
test="local test has changed";
}
});
}
}
}
答案 0 :(得分：0)
我有一个替代解决方案，即在调用活动（上一个活动）中触发asyncTask并将结果传递给bundle但我不喜欢这个解决方案，因为它很僵硬，可能会导致屏幕旋转问题。
这是一个很好的方法
覆盖onSaveInstanceState以在旋转之间保存额外内容
另请参阅here了解详情
编辑：您似乎正在尝试使用
更改文字test =＆＃34;本地测试已更改＆＃34 ;;
你需要做的是将活动传递给asynctask然后
VIEWTYPEHERE button= ( VIEWTYPEHERE) activity.findViewById(R.id.YOUR_VIEW"S_ID_HERE);
button.setText（＆＃34;＆＃34）;
几个笔记
关于post执行在ui线程上运行你不需要新的runnable 你忘了给它打电话.run（）