我试图理解为什么来自activity1的listview项目的点击需要一个记录时间（大约1秒）才能打开第二个活动。
我的代码似乎有实现或性能问题。
以下是我在listview项目上绑定点击的第一个活动（Main）的代码摘录：
list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Annonce currentAnnonce = (Annonce) list.getAdapter().getItem(position);
String titre = currentAnnonce.getTitle();
String cat = currentAnnonce.getCategorie();
String desc = currentAnnonce.getDescription();
String etat = currentAnnonce.getEtat();
String img = currentAnnonce.getImage();
String prix = currentAnnonce.getPrix();
String villeObj = currentAnnonce.getVilleObjet();
String codePostal = currentAnnonce.getCode_postal();
String departement = currentAnnonce.getDepartement();
String avatarUser = currentAnnonce.getImageUser();
String pseudoUser = currentAnnonce.getPseudoUser();
String dateDebut = currentAnnonce.getDate_debut();
String idAnnonce = currentAnnonce.getId();
String emailUser = currentAnnonce.getEmailUser();
String partel = currentAnnonce.getPartel();
String parmail = currentAnnonce.getParmail();
Intent myIntent = new Intent(Main_All_Annonces.this, Detail_annonce.class);
myIntent.putExtra("titre", titre);
myIntent.putExtra("cat", cat);
myIntent.putExtra("desc", desc);
myIntent.putExtra("etat", etat);
myIntent.putExtra("img", img);
myIntent.putExtra("prix", prix);
myIntent.putExtra("villeObj", villeObj);
myIntent.putExtra("codePostal", codePostal);
myIntent.putExtra("departement", departement);
myIntent.putExtra("avatarUser", avatarUser);
myIntent.putExtra("pseudoUser", pseudoUser);
myIntent.putExtra("dateDebut", dateDebut);
myIntent.putExtra("idAnnonce", idAnnonce);
myIntent.putExtra("emailUser", emailUser);
myIntent.putExtra("partel", partel);
myIntent.putExtra("parmail", parmail);
myIntent.putExtra("parentAct", "AllAnnonces");
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
// get the common element for the transition in this activity
final View image_view = findViewById(R.id.allannonces_image);
//String transitionName = (String) view.getTag(R.id.allannonces_image);
ActivityOptionsCompat options =
ActivityOptionsCompat.makeSceneTransitionAnimation(
Main_All_Annonces.this,
view, // The view which starts the transition
"transitionImg" // The transitionName of the view we’re transitioning to
);
// put more extras in the intent if you want, like the object clicked
myIntent.putExtra("EXTRA_IMAGE_TRANSITION_NAME", "transitionImg");
ActivityCompat.startActivity(Main_All_Annonces.this, myIntent, options.toBundle());
}
else {
// Code to run on older devices
startActivity(myIntent);
overridePendingTransition(R.anim.left_to_right, R.anim.right_to_left);
}
}
});
以下是我的Detail_annonce活动的代码：
public class Detail_annonce extends Activity {
HttpPost httppost;
StringBuffer buffer;
HttpClient httpclient;
List<NameValuePair> nameValuePairs;
ProgressDialog dialog = null;
DisplayImageOptions options;
LinearLayout btn_mail, btn_tel, btn_share;
View bar1, bar2;
String partel, parmail;
TextView nbAnnonceActionBar ;
@SuppressWarnings("unused")
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.detail_layout);
Typeface robotolight = Typeface.createFromAsset(getApplicationContext().getAssets(), "fonts/Roboto/Roboto-Light.ttf");
Typeface robotoBold = Typeface.createFromAsset(getApplicationContext().getAssets(), "fonts/Roboto/Roboto-Bold.ttf");
Typeface robotoRegular = Typeface.createFromAsset(getApplicationContext().getAssets(), "fonts/Roboto/Roboto-Regular.ttf");
bar1 = (View) findViewById(R.id.detail_view1);
bar2 = (View) findViewById(R.id.detail_view2);
options = new DisplayImageOptions.Builder()
.displayer(new RoundedBitmapDisplayer(2000))
.cacheOnDisc(true)
.build();
Intent previous = getIntent();
Bundle extras = previous.getExtras();
final String titre = extras.getString("titre");
String cat = extras.getString("cat");
String desc = extras.getString("desc");
String img = extras.getString("img");
final String prix = extras.getString("prix");
final String villeObj = extras.getString("villeObj");
final String codePostal = extras.getString("codePostal");
String avatarUser = extras.getString("avatarUser");
final String pseudoUser = extras.getString("pseudoUser");
String dateDebut = extras.getString("dateDebut");
final String idAnnonce = extras.getString("idAnnonce");
final String emailUser = extras.getString("emailUser");
partel = extras.getString("partel");
parmail = extras.getString("parmail");
String parentAct = extras.getString("parentAct");
ImageView image_txt = (ImageView) findViewById(R.id.detail_annonce_image);
TextView titre_txt = (TextView) findViewById(R.id.detail_annonce_titre);
TextView prix_txt = (TextView) findViewById(R.id.detail_annonce_prix);
TextView dateDebut_txt = (TextView) findViewById(R.id.detail_annonce_date_debut);
TextView villeAndCodePostal = (TextView) findViewById(R.id.detail_annonce_ville_and_codePos);
ImageLoader imageLoader = ImageLoader.getInstance();
Double latitude = null, longitude = null;
Geocoder geo = new Geocoder(getBaseContext(), Locale.getDefault());
try {
List<Address> addresses = geo.getFromLocationName(villeObj, 10);
Address currentFound = addresses.get(0);
if (currentFound.hasLatitude() && currentFound.hasLongitude()) {
latitude = currentFound.getLatitude();
longitude = currentFound.getLongitude();
}
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
ViewCompat.setTransitionName(image_txt, getIntent().getStringExtra("EXTRA_IMAGE_TRANSITION_NAME"));
imageLoader.displayImage(img, image_txt);
titre_txt.setText(titre);
titre_txt.setTypeface(robotoRegular);
prix_txt.setText("€" + prix + ",00 EUR");
prix_txt.setTypeface(robotolight);
villeAndCodePostal.setText("Disponible à " +villeObj);
villeAndCodePostal.setTypeface(robotolight);
////////////////
/// DATE
////////////////
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.getDefault());
Date pDate;
try {
pDate = df.parse(dateDebut);
dateDebut = DateUtils.getDateDifference(pDate);
dateDebut = dateDebut.replace("-", "");
} catch (ParseException e) {
Log.e("DATE PARSING", "Error parsing date..");
}
dateDebut_txt.setText("Posté il y a " + dateDebut + "dans la catégorie " +cat);
dateDebut_txt.setTypeface(robotolight);
if (latitude != null && longitude != null ) {
// Get a handle to the Map Fragment
GoogleMap map = ((MapFragment) getFragmentManager() .findFragmentById(R.id.map)).getMap();
LatLng ville = new LatLng(latitude, longitude);
map.setMyLocationEnabled(true);
map.moveCamera(CameraUpdateFactory.newLatLngZoom(ville, 9));
map.addMarker(new MarkerOptions()
.title(villeObj)
.visible(true)
.snippet("La vente se fait à cet adresse.")
.position(ville));
}
}
答案 0 :(得分：2)
当Android启动您的新活动时，它会在显示任何内容之前执行onCreate() 中的所有代码。
通常我所做的（作为专业的Android开发人员）只抓取我在onCreateView()中保留为类变量的视图，然后将所有填充代码放在onStart()中。如果您的活动在切换活动后显示数据需要一段时间，您可以将ProgressSpinner视图放在前面，这样您的用户就知道数据仍在处理中。
在您的情况下，绝对可以使用onCreate()中的所有Google地图代码。 Google地图非常受欢迎，有时服务器需要一段时间才能满足您的要求。
附注：
我同意评论者关于将您的对象作为额外内容进行传输。为此，您必须将对象标记为Serializable。 See this SO question. 查看投票率最高的答案，而不是“已接受”的答案。
模块化您的代码！将一些内容分成辅助方法，然后在onCreateView()和onStart()方法中调用它们。它将使代码移动更容易。
您应该考虑使用单个Actvitity并仅使用片段来处理所有单独的屏幕（弹出窗口除外）。片段可以帮助您的代码更加面向对象，并避免重复这么多代码。 Google似乎也在努力推动Fragment-Decorator的设计模式。然而，这最终归结为个人偏好。
修改：More info about Activity lifecycle methods here.注意{<1}}在之前如何调用，表示活动已“创建”。
答案 1 :(得分：-1)
使用GSON库。这对你有好处。