嗨，我有一个用户在点击选项卡时打开的活动。实际上我有一个 ViewGroup 和 Tabactivity 作为主要活动。在第一个选项卡上，我有三个活动。
现在在一个活动中，我在 Oncreate 上填充了一个列表视图（自定义），在 Onresume 中使用 AsyncTask 填充了一个 ViewFlipper（仅添加视图）。
在 Pre Execute 的那个异步任务中，如果我为加载程序添加代码，它会出错。此外，如果我不显示加载程序，则屏幕会冻结，直到异步任务完成。
我实际上想先加载列表视图，然后在后台使用加载器运行异步任务。也不想冻结屏幕。
这是我的活动
package thai.phrasi.ctech.com.phrasi;
import android.app.AlertDialog;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Typeface;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.ViewFlipper;
import com.squareup.picasso.Picasso;
import org.json.JSONObject;
import java.lang.ref.WeakReference;
import java.util.ArrayList;
public class WordActivity extends ActionBarActivity {
categories category_obj;
word word_obj;
wordDB wordDb;
WordAdapter adapter;
MediaPlayer mPlayer;
boolean doubleBackToExitPressedOnce = false;
public static ViewFlipper viewFlipper;
public View view;
private static ProgressDialog pleaseWaitDialog;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_word);
viewFlipper = new ViewFlipper(this);
viewFlipper.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
TextView txt = (TextView) findViewById(R.id.phraseListHeading);
Typeface font = Typeface.createFromAsset(WordActivity.this.getAssets(), "fonts/NotoSans-Regular.ttf");
String categoryName = getIntent().getExtras().getString("categoryName").toUpperCase();
wordDb = new wordDB(getApplicationContext());
getAllWords();
//asyncLoadWordList task2 = new asyncLoadWordList(getApplicationContext());
//task2.execute();
txt.setTypeface(font);
txt.setText(categoryName);
ListView wordListView;
wordListView = (ListView)findViewById(R.id.list_view_word);
wordListView.setOnItemClickListener(new AdapterView.OnItemClickListener(){
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Object o = parent.getItemAtPosition(position);
word_obj = (word) o;
if(Integer.valueOf(word_obj.getCategoryId())>=0) {
Intent myIntent = new Intent(WordActivity.this, WordDetailsActivity.class);
myIntent.putExtra("word_obj", word_obj);
myIntent.putExtra("position",position);
myIntent.putExtra("currentClickedId", word_obj.getCsvWordId().toString());
myIntent.putExtra("favouriteFlag",0);
myIntent.putExtra("searchFlag",0);
myIntent.putExtra("searchString", "");
WordActivity.this.startActivity(myIntent);
}
}
});
ImageView backButton = (ImageView) findViewById(R.id.backButton);
backButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent backIntent = new Intent(WordActivity.this, CategoryActivity.class);
View vw = FirstGroup.group.getLocalActivityManager().startActivity("CategoryActivity", backIntent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)).getDecorView();
FirstGroup.group.replaceView(vw);
viewFlipper.removeAllViews();
System.runFinalization();
Runtime.getRuntime().gc();
System.gc();
}
});
}
@Override
protected void onPause() {
super.onPause(); // Don't forget this line
stop();
}
public void stop(){
mPlayer=adapter.getMPlayerInstace();
if(mPlayer!=null){
mPlayer.stop();
mPlayer.release();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_word, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
protected void onResume(){
super.onResume();
new Thread(new Runnable() {
public void run(){
//All your heavy stuff here!!!
category_obj = (categories) getIntent().getSerializableExtra("category_obj");
if(viewFlipper.getChildCount() == 0) {
asyncFlipperView task = new asyncFlipperView(getApplicationContext());
task.execute(new String[]{category_obj.getCsvCategoryId().toString()});
}
}
}).start();
}
public void getAllWords(){
category_obj = (categories) getIntent().getSerializableExtra("category_obj");
ArrayList<word> words = new ArrayList<word>();
Cursor row = wordDb.selectWordList(category_obj.getCsvCategoryId().toString());
words.add(new word("-1", "-1", "", "", "", "", "", "", "x.mp3", ""));
words.add(new word("-2", "-2", "", "", "", "", "", "", "x.mp3", ""));
row.moveToFirst();
while (!row.isAfterLast()) {
//Log.d("Data id: ", row.getString(2));
words.add( new word(row.getString(0),row.getString(1),row.getString(2),row.getString(3),row.getString(4),row.getString(5), row.getString(6),row.getString(7),row.getString(8),row.getString(9)));
row.moveToNext();
}
row.close();
adapter = new WordAdapter(WordActivity.this, words);
ListView listView = (ListView) findViewById(R.id.list_view_word);
listView.setAdapter(adapter);
}
@Override
public void onBackPressed() {
if (doubleBackToExitPressedOnce) {
super.onBackPressed();
return;
}
this.doubleBackToExitPressedOnce = true;
//Toast.makeText(this, "Please click BACK again to exit", Toast.LENGTH_SHORT).show();
LayoutInflater inflater = getLayoutInflater();
View layout = inflater.inflate(R.layout.custom_toast, (ViewGroup) findViewById(R.id.toast_layout_root));
TextView text = (TextView) layout.findViewById(R.id.text);
text.setText("Double tap back button to exit.");
Toast toast = new Toast(getApplicationContext());
toast.setGravity(Gravity.CENTER_HORIZONTAL, 0, 0);
toast.setGravity(Gravity.CENTER_VERTICAL, 0, 0);
toast.setDuration(Toast.LENGTH_SHORT);
toast.setView(layout);
toast.show();
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
doubleBackToExitPressedOnce = false;
}
}, 2000);
}
public class asyncLoadWordList extends AsyncTask<ArrayList<word>, Void, ArrayList<word>>{
private Context mContext;
public asyncLoadWordList(Context context) {
mContext = context;
}
protected void onPreExecute() {
//Start the splash screen dialog
/* if (pleaseWaitDialog == null)
pleaseWaitDialog= ProgressDialog.show(WordActivity.this,
"PLEASE WAIT",
"Getting results...",
false);
*/
}
@Override
protected ArrayList<word> doInBackground(ArrayList<word>... params) {
wordDb = new wordDB(mContext);
category_obj = (categories) getIntent().getSerializableExtra("category_obj");
ArrayList<word> words = new ArrayList<word>();
Cursor row = wordDb.selectWordList(category_obj.getCsvCategoryId().toString());
words.add(new word("-1", "-1", "", "", "", "", "", "", "x.mp3", ""));
words.add(new word("-2", "-2", "", "", "", "", "", "", "x.mp3", ""));
row.moveToFirst();
while (!row.isAfterLast()) {
//Log.d("Data id: ", row.getString(2));
words.add( new word(row.getString(0),row.getString(1),row.getString(2),row.getString(3),row.getString(4),row.getString(5),row.getString(6),row.getString(7),row.getString(8),row.getString(9)));
row.moveToNext();
}
row.close();
return words;
}
protected void onPostExecute(ArrayList<word> result) {
adapter = new WordAdapter(WordActivity.this, result);
ListView listView = (ListView) findViewById(R.id.list_view_word);
listView.setAdapter(adapter);
if (pleaseWaitDialog != null) {
pleaseWaitDialog.dismiss();
pleaseWaitDialog = null;
}
asyncFlipperView task = new asyncFlipperView(getApplicationContext());
task.execute(new String[]{category_obj.getCsvCategoryId().toString()});
}
}
public class asyncFlipperView extends AsyncTask<String, Void, String[]> {
String categoryId;
private Context mContext;
wordDB wordDb;
Cursor row;
JSONObject json;
View view;
//private ProgressDialog dialog = new ProgressDialog(WordActivity.this);
public asyncFlipperView(Context context) {
mContext = context;
}
protected void onPreExecute() {
//Start the splash screen dialog
}
@Override
protected String[] doInBackground(String... params) {
categoryId = params[0];
json = new JSONObject();
/*do application level task*/
GlobalState state = ((GlobalState) mContext);
state.doAction();
/*Ends*/
wordDb = new wordDB(mContext);
row = wordDb.selectWordList(categoryId);
Log.d("Tag: search result", row.getString(2).toString());
return new String[]{categoryId};
}
protected void onPostExecute(String[] result) {
categoryId = result[0];
ImageView phraseImage = null;
Typeface font = Typeface.createFromAsset(WordActivity.this.getAssets(), "fonts/NotoSans-Regular.ttf");
row.moveToFirst();
while (!row.isAfterLast()) {
/*phrase Image*/
Integer fileNameLength = row.getString(5).toString().length();
String fileName = row.getString(5).toString();
String imageFile = fileName.substring(0, fileNameLength - 4);
//viewFlipper = (ViewFlipper)findViewById(R.id.flipper);
LayoutInflater inflater = getLayoutInflater();
view = inflater.inflate(R.layout.word_details_flipper_view, null);
TextView tv = (TextView) view.findViewById(R.id.text_english);
tv.setTypeface(font);
tv.setText(row.getString(2).toString());
String picName = row.getString(6).toString();
picName = picName.replace(".png", "");
Uri url1 = Uri.parse("android.resource://" + mContext.getPackageName() + "/drawable/" + picName);
ImageView backgroundImage = (ImageView) view.findViewById(R.id.backgroundImage);
Picasso.with(mContext).load(url1).fit().centerCrop().into(backgroundImage);
TextView tvTranslated = (TextView) view.findViewById(R.id.translated_phrase);
tvTranslated.setTypeface(font);
tvTranslated.setText(row.getString(3).toString());
TextView pronounce = (TextView) view.findViewById(R.id.pronounce);
pronounce.setTypeface(font);
pronounce.setText(row.getString(4).toString());
phraseImage = (ImageView) view.findViewById(R.id.phrase_image);
Uri url = Uri.parse("android.resource://" + mContext.getPackageName() + "/drawable/" + imageFile);
Picasso.with(mContext).load(url).resize(576, 888).into(phraseImage);
view.setTag(R.string.csvId, row.getString(0).toString());
viewFlipper.addView(view);
row.moveToNext();
}
row.close();
}
private Context getDialogContext() {
Context context;
if (getParent() != null) context = getParent();
else context = WordActivity.this;
return context;
}
}
}