I am creating an android app myself (min sdk version 7 or 2.1 and up). And it was going fine until I decided I was going to need a TabLayout. I added a new class, and had it extend TabActivity, however when launching the app in an AVD it crashed and stated this in the log that there was an uncaught exception. And that it could not launch the activity.
ThermostatTabHost.java (note, I did not add package/import to save some space):
public class ThermostatTabHost extends TabActivity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.tabmain);
Resources res = getResources(); // Resource object to get Drawables
TabHost tabHost = getTabHost(); // The activity TabHost
TabHost.TabSpec spec; // Resusable TabSpec for each tab
Intent intent; // Reusable Intent for each tab
// Create an Intent to launch an Activity for the tab (to be reused)
intent = new Intent().setClass(this, ThermostatActivity.class);
// Initialize a TabSpec for each tab and add it to the TabHost
spec = tabHost.newTabSpec("Temperature").setIndicator("Program",
res.getDrawable(R.drawable.arrow_up))
.setContent(intent);
tabHost.addTab(spec);
}
}
The ThermostatActvity class currently only holds a onCreate function which calls super.onCreate(savedInstance) and sets a layout with a textview.
The tabmain.xml file:
<?xml version="1.0" encoding="utf-8"?>
<TabHost xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#android:id/tabhost"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="5dp">
<TabWidget
android:id="#android:id/tabs"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
<FrameLayout
android:id="#android:id/tabcontent"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="5dp" />
</LinearLayout>
</TabHost>
And finally the manifest file:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.pack.thermostat"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="7" />
<application
android:icon="#drawable/ic_launcher"
android:label="#string/app_name" >
<activity
android:name=".ThermostatTabHost"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
This example came straight of the android developers website (with a few minor changes), I also looked around for similar issues but I couldn't come up with anything.
Thank you in advance.
Add this "ThermostatActivity" in your manifeast file
Related
[Android Studio] I'm trying to get a few frames to display quickly one after another and then change to a different activity automatically on startup.
I'm able to make the splash activity wait the appropriate amount of time before proceeding, but the animation still isn't playing.
I'm using this person's method (https://www.youtube.com/watch?v=lGRWYJlS3d0) to animate the frames and display them to an ImageView - in the example, the animation is controlled by a stop and start button which sets the frames to loop endlessly (or not), however I would just like it to be activated and displayed when the app is launched.
The way I'm currently implementing this method is causing the app to crash once particular lines are read, but I'm probably just doing it wrong so any help will be appreciated. Thanks. :)
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.company.framebyframe">
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".SplashActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.HOME" />
<category android:name="android.intent.category.MAIN" />
</intent-filter>
</activity>
</application>
</manifest>
activity_splash.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/splash_layout"
android:background="#drawable/custom_animation">
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<ImageView
android:id="#+id/imageView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center" />
</FrameLayout>
</android.support.constraint.ConstraintLayout>
custom_animation.xml under drawables
<?xml version="1.0" encoding="utf-8"?>
<animation-list xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="#drawable/image0" android:duration="250"/>
<item android:drawable="#drawable/image1" android:duration="100"/>
<item android:drawable="#drawable/image2" android:duration="100"/>
<item android:drawable="#drawable/image3" android:duration="100"/>
<item android:drawable="#drawable/image4" android:duration="750"/>
<item android:drawable="#drawable/image3" android:duration="750"/>
<item android:drawable="#drawable/image4" android:duration="750"/>
<item android:drawable="#drawable/image3" android:duration="500"/>
<item android:drawable="#drawable/image0" android:duration="5000"/>
</animation-list>
SplashActivity.java
public class SplashActivity extends AppCompatActivity {
AnimationDrawable anim;
ImageView imageView;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
imageView = (ImageView) findViewById(R.id.imageView);
imageView.setBackgroundResource(R.drawable.custom_animation);
anim = (AnimationDrawable) imageView.getBackground();
anim.start();
// // start new activity after 3.5 seconds // //
final Handler handler = new Handler();
handler.postDelayed(new Runnable() {
#Override
public void run() {
startNextActivity();
}
}, 3500);
}
public void startNextActivity() {
if (isFinishing())
return;
startActivity(new Intent(SplashActivity.this, MainActivity.class));
finish();
}
crashes tend to occur when i start unquoting these lines:
imageView = (ImageView) findViewById(R.id.imageView);
imageView.setBackgroundResource(R.drawable.custom_animation);
PS: if there are any naming mistakes, it might be due to me trying to make the filenames more generic and understandable, but feel free to point out anything you believe might cause problems.
You need to set the layout on the activity class, otherwise the application won't know what layout if should inflate. That's the main reason your application crashes when you try to find the image view, because you haven't set the content layout. Add this line just after super.onCreate and before you try to manipulate any UI element
setContentView(R.layout.activity_splash);
Also, remove the background declaration on the constraint layout, you're already loading the animated drawable to an image view
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/splash_layout">
...
</android.support.constraint.ConstraintLayout>
I'm attempting to get a simple map based app running but when I install on device and try to "open" I receive the error "unfortunately application has stopped" On emulator I receive the message :
[2014-03-18 21:37:16 - FirstMap] Installation error: Unknown failure
[2014-03-18 21:37:16 - FirstMap] Please check logcat output for more details.
[2014-03-18 21:37:16 - FirstMap] Launch canceled!
Why do I receive this message ? I think my code looks good as I have followed these steps : https://developers.google.com/maps/documentation/android/v1/hello-mapview ?
Here is my code :
MainActivity.java :
package com.example.firstmap;
import android.os.Bundle;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapView;
public class MainActivity extends MapActivity {
#Override
protected boolean isRouteDisplayed() {
return false;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
MapView mapView = (MapView) findViewById(R.id.mapview);
mapView.setBuiltInZoomControls(true);
}
}
main.xml :
<?xml version="1.0" encoding="utf-8"?>
<com.google.android.maps.MapView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/mapview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:clickable="true"
android:apiKey="mykey"
/>
AndroidManifect.xml :
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.firstmap"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="18" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.firstmap.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
Refer to my post here:
Want to use GoogleMaps - OnMyLocationChangeListener but can't implement it? Any other options
I have described what exactly to use and how.
Hope you find it helpful .. :)
There are many things missing from your manifest file. Try following the official instructions on how to use google maps google map instructions
The instructions you followed refer to version 1 google maps for android which is deprecated.
Use Google Map Api V2, The important changes that you will have to make is
1) Make use of
<fragment
android:id="#+id/map"
android:name="android.app.DialogFragment"
android:layout_width="match_parent"
android:layout_height="match_parent" />
i.e You have to use fragment tag in activity_main.xml instead of the mapview tag.
2) Refer Google play services.....
example: Google Maps Can't add reference to Play Services
Best Link to refer for newbies implementing Google Maps Api V2: http://www.androidhive.info/2013/08/android-working-with-google-maps-v2/
I am new to eclipse/Java. I searched for answer but nothing solved my problem. I hope someone can guide me. I am attempting to launch a webpage withing an android application however I am getting a blank page in the Android Virtual Emulation.
Here is my code
package com.example.t4;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.webkit.WebView;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
WebView myWebView = (WebView) findViewById(R.id.webview);
myWebView.loadUrl("http://www.google.com");
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
Here is the AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.t4"
android:versionCode="1"
android:versionName="1.0" >
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="18" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.t4.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
and here is the activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<WebView
android:id="#+id/webview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
</LinearLayout>
I am not sure what I am doing wrong. The code runs without an error. I just get a blank screen. Any help is much appreciated. Thanks in advance.
try to put myWebView.getSettings().setJavaScriptEnabled(true); // enable javascript
myWebView.loadUrl("http://www.google.com");
Check out this working basic webview. I tested with "www.google.com" like yours and came up with a blank view. I used "http://www.google.com" and it ran fine. Try that out on yours? But feel free to steal the sample code too.
Restart your app (I mean click Run again) and make sure you have enabled javaScript as mentioned above.
I have the famous error message “R cannot be resolved to a variable” since the last 3 days and I’m totally stuck.
I did follow the instructions in the following links but I can’t remove this error:
Developing for Android in Eclipse: R.java not regenerating
I have crated plenty of new projects with just a new title but the same.
I even today uninstall completely Eclipse , jdk, jre and reinstall all but the same…
**Config: Windows 7 64 bits
eclipse-standard-kepler-SR1-win32-x86_64
jdk-7u51-windows-x64
jre-7u51-windows-x64
Android sdk downloaded**
I have noticed there is no file in the folder “gen” is always empty..
Thank you for your help
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Mainactivity.java:
package com.example.test1;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
activity_maim xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/hello_world" />
</RelativeLayout>
manifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.test1"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="18" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.test1.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
This looks like a 64bit issue, as android is looking for a 32bit ADT, there are a few options to solve this. Have a look at this question: Android SDK Setup under Windows 7 Pro 64 bit
I solved this under linux by doing sudo apt-get install ia32-libs
Have you checked your manifest.xml for mistakes?
I once had a small error in my manifest that didn't show up as an error and it wouldn't generate a new R file.
I noticed another small thing that might be the issue, in your main_activity.xml you use dimension strings for padding, when creating a new project these strings are located in res/values/dimens.xml but in your layout file you are referring to #dimen instead of #dimens (notice the missing 's').
Try changing it to "#dimens/..."
I am splitting this off from my other thread here: Display image in popout window after button is clicked -- Android/Java
The old thread got very convoluted and confusing, and a bit off-topic, so I wanted to create another one that is clearer with more information.
I am trying to display an image in Android using an image file path that changes every time the app is run. I know there are ways to declare resources in the XML layout file, but since the picture I'd like to display is taken from the camera, I can't do it that way. I need to be able to display the image without hardcoding it.
The following is the code that I have:
photo_viewer.xml:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/pictureViewer"
android:layout_width="wrap_content"
android:layout_height="wrap_content" >
<ImageView
android:id="#+id/imageView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:contentDescription="#string/viewImage" />
</RelativeLayout>
Java method to display image:
public void viewPhoto(String file){
ImageView imageView = new ImageView(getApplicationContext());
LayoutParams lp = new LayoutParams(LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT);
Bitmap image = BitmapFactory.decodeFile(file);
imageView.setImageBitmap(image);
RelativeLayout rl = (RelativeLayout)findViewById(R.id.pictureViewer);
rl.addView(imageView, lp);
}
However, when I run the above code the application crashes, saying it has stopped working. "file" is a string denoting the directory where the image from the camera is stored, and I know this part is correct. I can use it (using a different method) to change the wallpaper. It's just displaying it that is causing me trouble. I have tried various methods to simply display the image (dialogs, "drawable"s, bitmap factory, etc) and had the same problem with all of them. I feel like it's something simple that I have missed, since I'm new to Android app development. I'm hoping one of you folks might be able to shed some light on this.
EDIT:
I have decided to try another route, but I am still getting a null pointer exception. Here is all my code:
main class, viewPhoto method:
/* View photo */
public void viewPhoto(String file){
Intent imageView = new Intent(this, PhotoViewer.class);
imageView.putExtra("directory", file);
startActivity(imageView);
}
PhotoViewer class:
package com.androidproject;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.widget.ImageView;
import android.widget.RelativeLayout;
public class PhotoViewer extends Activity {
public String file;
ImageView image;
#Override
protected void onCreate(Bundle bundle) {
super.onCreate(bundle);
setContentView(R.layout.photo_viewer);
//get file path of image
Bundle extras = getIntent().getExtras();
file = extras.getString("directory");
Drawable drawable = Drawable.createFromPath(file);
image.setImageDrawable(drawable);
}
}
photo_viewer.xml (created using the Eclipse tool, so it's not just any xml file)
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/photo_viewer"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".PhotoViewer" >
<ImageView
android:id="#+id/imageView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:contentDescription="#string/viewImage"/>
</RelativeLayout>
Project manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.androidproject"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="18" />
<uses-permission android:name="android.permission.CAMERA"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.SET_WALLPAPER" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name=".Main"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".PhotoViewer"
android:label="#string/app_name" >
<intent-filter>
<action android:name="com.androidproject.PhotoViewer" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
</application>
</manifest>
The app continues to crash and tell me "unfortunately it stopped working". Here's the logcat of the error:
As always, help is appreciated!
The null pointer exception is because
Drawable drawable = Drawable.createFromPath(file);
image.setImageDrawable(drawable);
is referencing an uninitiated variable (image) which is null
My best guess would be that to eliminate said error you'd want to initiate the variable
ImageView image = (ImageView)findViewById(R.id.imageView);