I wrote CustomView Class, and load it in layout. so i trid to find CustomView using findViewById() in activiy to get handle. but findViewById() was return null.
Written Code is like below:
CODE:.........
MapCanvas.java:
CODE:...............
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first of all: yes, I read all the other threads on this topic. And not only those from this site... (you see, i'm a little frustrated) Most of them come with the advice to use "android:id" instead of just "id" in the xml file. I did. From others, i learned, that View.findViewById works different than Activity.findViewById. I handled that, too.
in my location_layout.xml i use
<FrameLayout .... >
<some.package.MyCustomView ... />
<LinearLayout ... >
<TextView ...
android:id="@+id/txtLat" />.................
As the title says? Or what situations can cause this method to return null? I would of thought it retained this object always.
View 2 Replies View RelatedI have super.xml and a subset.xml.
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I get a null pointer exception at price.setText(data.getStrTotalPrice()); Very strange, name.setText(data.getStrDescription()); does not give a null pointer exception.
I am having a problem where in the started Intent, the findViewById returns null. Is there anything special I should know about starting a new intent? It goes something like this for me:
//in the MainList class
Intent stuffList = new Intent(this, StuffList.class);
then in the new Stuff's constructor:...............
I have a class that is called when my app launches. public class MainActivity extends Activity implements NetworkEvent.
In this situation, list = (ListView) findViewById(R.id.list); works perfectly.
However if I then call a new intent via:
CODE:.........
where SimpleList is defined as: public class SimpleList extends ListActivity implements NetworkEvent then when I call
CODE:.........
From within the SimpleList class, list is null :(
How come? Both classes are within the same package.
I'm following this tutorial here: http://developer.android.com/guide/tutorials/views/hello-mapview.html
and am on point 11
Here's the res/layout/main.xml:
CODE:........
Here's the code:
CODE:........................
trying to find some performance numbers for findViewById - need to convince to change bunch of the findViewById for the same widget to member variable with just one findViewById on create . Or may be i'm wrong and it's fine ?
View 6 Replies View RelatedI'm trying to get the ANDROID_ID on two different devices but it always return null on both. I'm using a Google Ion (aka HTC Magic) with firmware 1.6 and a Motorola Milestone with firmware 2.0.
I've been using this small sample to show the id, but it always shows null:
CODE:........................
I have created a simple driver to implement mmap and an application program to uses the sys call mmap and tries writ/read data. The mmaped area is the RAM.(I am working on beagle board) This works fine when I execute my application program through the shell/console but fails (with the following error) to work when executed through an apk. Unable to handle kernel NULL pointer dereference at virtual Code...
View 2 Replies View RelatedDo the Android users have the chance to reset the NetworkProvider, so that the location will be null?
I came up with the idea, that its only possible to have that location null, after starting the device the very first time. But also than google will check the location right away for my opinion.
Sure, I'm implementing a default location for this rare case. I just want to know how seldom this case is.
I am doing some android application. I just wonder what will case the managedQuery method return a null value?
I'm building an android app and I'm currently having trouble retrieving a bitmap from an URL.
Here is the code I'm using :
CODE:..........
Everything works fine when the picture's write but when some bytes are wrong, result gets null. I think it's basically expectable as it's written this in the doc of BitmapFactory.decodeStream :
If the input stream is null, or cannot be used to decode a bitmap, the function returns null. The stream's position will be where ever it was after the encoded data was read.
The problem is, my wrong picture is well interpreted by my web browser and I can do so on iPhone platform.
Is there a way to sort of ignore those wrong pixels? maybe with the option parameter?
Would it be there noticeable speed improvement if I would create local references to needed view elements (e.g. EditText or Button) in my activity (in onCreate()) and use them for accessing needed elements or it does not much matter if I always use findViewById() when I need to access some particular element?
View 2 Replies View RelatedI have a TabActivity, and each Tab corresponds to its own Activity. In one of them, in the onCreate method, I use startActivityForResult to show a dialog (specifically, Bump's BumpAPI activity).
code:...............
The problem is that when the screen orientation changes, it tries to create the tab's activity again which makes another BumpAPI dialog, resulting in multiple stacked on top of each other. Do I have a hook into the started activity to cancel the previous one when the orientation changes?
A workaround seems to be to add a button that when clicked, starts the second activity, but that adds an unnecessary step.
Also, I can't fix the screen orientation for the entire tabActivity because some of them require typing and users may want to use their physical keyboards.
why CheckBox is always null.
<CheckBox id="@+id/checkbox" android:layout_width="wrap_content" android:layout_height="wrap_content" />
code file-
package com.reblogr.reblogrclient;
public class Test extends Activity { /** Called when the activity is first created. */
public CheckBox checkbox;
@Override public void onCreate(Bundle savedInstanceState) { ....................
I have an application with contains multiple activities. The main activity will start the others ( use startActivity() ) depends on user event, when an activity close, it calls finish() and return back to main activity. It appears to behavior like that.
However, the "problem" I see is main activity's onCreate function is called every time. I think the the main activity should be placed in the activity stack and simply push to front when others exit, therefore only onResume, onStart are called. Is there some flag I need to set or I misunderstand the activity behaviro?
In child activity, besides calling finish() or startActivity for main activity, what is other way to move main activity to front?
Experts: My MainActivity launches a SubActivity by calling: startActivityForResult(intent, REQ_CODE); The SubActivity shows a dialog that has two buttons: Yes, No For the dialog, I've the following code: public void onClick(DialogInterface dialog, int whichButton) {/* User clicked OK */setResult(DialogInterface. BUTTON_POSITIVE) ;finish();
View 2 Replies View RelatedI have a main screen with buttons to launch other subactivities. I have to press back button each time to go back to the main screen of my application. How do I finish a child activity and automatically return from the caller?
View 5 Replies View RelatedI have a res/layout/main.xml including these elements and others:
<some.package.MyCustomView android:id="@+id/foo" (some other params) />
<TextView android:id="@+id/boring" (some other params) />
In my Activity's onCreate, I do this:
setContentView(R.layout.main);
(TextView) boring = findViewById(R.id.boring);
// ...find other elements...
MyCustomView foo = (MyCustomView) findViewById(R.id.foo);
if (foo == null) { Log.d(TAG, "epic fail"); }
The other elements are found successfully, but foo comes back null. MyCustomView has a constructor MyCustomView(Context c, AttributeSet a) and a Log.d(...) at the end of that constructor appears successfully in logcat just before the "epic fail".
findViewById() returns null for custom component in layout XML, not for other components. Why is foo null?
I'm having difficulties handling multiple instances of my root (main) activity for my application. My app in question has an intent filter in place to launch my application when opening an email attatchment from the "Email" app. My problem is if I launch my application first through the the android applications screen and then launch my application via opening the Email attachment it creates two instances of my root activity. steps: Launch root activity A, press home Open email attachment, intent filter triggers launches root activity A Is it possible when opening the Email attachment that when the OS tries to launch my application it detects there is already an instance of it running and use that or remove/clear that instance?
View 1 Replies View RelatedI am writing an activity, that loads data from a server and displays it as a list using ArrayAdapter. For that I'm showing a progress dialog i.e loading, while it loads all data from the server. Then i dismiss the dialog in a handler. My problem is that when ever i change the orientation, the progress dialog is again shown, which is not needed, because all the data is displayed already?
View 1 Replies View RelatedHow to handle Home key....Plzz Help me out.We can handle Home button.if you have seen the Nexus One device...when u reset the phone ..and switch it on again some tutorials kind of thng comes..at that time wen u press the home button its not taking u to the Launche Activity...if its not possible then how they are handling over there.I want the Answer..No one in this Blog has any idea how to handle it....or no one has tried on this..sum are sayng that we can handle it by PhoneWindowManager.java class,some r sayng we can handle it by Using onNewINtent() method.But the Question is how we can handle it by these two ways...Just provide me the sample code..where we are handling the HomeKey.
View 9 Replies View RelatedI have an Activity that will query a RESTful API every x seconds (polls using a handler). The results of the GET are used to update a ListView. This is done using an AsyncTask.
I want to put a Notification in the Notification bar when certain criteria are met in the new data. Everything I have read up to this point has suggested that notifications should be created and updated using a service so that the notifications can be made even when the application isn't in focus. I see the positive aspects of this.
However, I'm unsure if I should just create a service from within my activity or if I need to do something more complex than that. I'm undecided on if I should scrap my AsyncTask model in favor of using the Service to update my list view.
So, my questions are:
1) Is there a good tutorial showing how to make a local service from an activity?
The tutorial doesn't need to show how to make them communicate, the service could be isolated from the main activity.
2) Will #1 provide me with the notification benefits I'm looking for? (Notifications are generated even when the main app isn't visible)
3) Should I use this same service to update my listview?
The service would basically be making the same query that the AsyncTasks are, just doing different things with the results. The app would seem to make more sense to have the Service query, do notification processing, then give the results to the activity, but I haven't found a good resource that clearly demonstrates how to do something like this.
I am tring to invote internal media player of android from my activity. Seems there is some problem in menifest file .
Please look into this issue .
CODE:...........................
I have a problem regarding my intent. It seems that my app crashes when i select the intent. I found the line of error code due to the stack trace. But i couldn't find anything wrong with it. Hope anyone can help me with this.
This is the java code in line 121:
CODE:..............
This is the stack trace:
CODE:....................................
I am following the Parcelable example in the Android developer guide with the intention of having a more complex object that I send to different activities. Right now, my class is a wrapper of a String member. If I put the object in the intent and read it back from the Intent it reads as expected, however, on the receiver side, it is always null-pointer.
View 1 Replies View RelatedI've followed the SearchManager documentation yet am still having trouble making one of my app's activities searchable. From my activity, the Search dialog appears, I enter a query, hit search, my activity reopens, then I see this in the log:
CODE:.....................
It appears to me that everything is fine up until the last three lines. The "NI" lines are getIntent().toString(), getIntent().getAction(), and getIntent().hasExtra(SearchManager.QUERY) respectively.
ActivityManager appears to be starting my activity with the correct action. Then when my activity starts, it contains no action!? What am I doing wrong?
The relevant portion of my manifest is:
CODE:..............................
I'm having a couple of problems with an alarm app I am developing.
The first thing that I think is a bit weird is that when an alarm goes of and wakes the phone up. These things happend.
oncreate
onresume
onpause
onresume
Why are they run in that order? The last two should not be called? And this is what's causes me big trouble, because when i press home or back on the phone, onPause is run, which I want to call finish() from. And that part works as it should, but that does not work when the phone wakes upp from sleep bacause of the onPause call...
test.class type is right? How to? What should I do?
CODE:...............