Develop Reference

How to open PDF file in android device?

I am fresher to android. My task is to open a pdf file in android device. I searched a tutorials and tried it. But I could not open a pdf file. I dont know the error where I did?. Please help me anyone.
activity_main.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:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/hello_world" />
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/textView1"
android:layout_centerHorizontal="true"
android:layout_marginTop="106dp"
android:text="open" />
</RelativeLayout>
MainActivity.java
package com.example.pdftest;
import java.io.File;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.app.Activity;
import android.content.ActivityNotFoundException;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends Activity implements OnClickListener{
private Button b1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
b1=(Button)findViewById(R.id.button1);
b1.setOnClickListener(this);
}
#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;
}
#Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
File pdffile=new File(Environment.getExternalStorageDirectory(),"/sdcard/abc.pdf");
try
{
if(pdffile.exists())
{
Uri path=Uri.fromFile(pdffile);
Intent objintent=new Intent(Intent.ACTION_VIEW);
objintent.setDataAndType(path, "application/pdf");
objintent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(objintent);
}
else
{
Toast.makeText(MainActivity.this,"File Not Found",Toast.LENGTH_SHORT).show();
}
}
catch(ActivityNotFoundException e)
{
Toast.makeText(MainActivity.this,"No viewer application Found",Toast.LENGTH_SHORT).show();
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.pdftest"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="18" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.pdftest.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>

You have to remove the root from the second parameter in File class constructor. When you're instantiating File with File(String dirPath, String name) then the second parameter must contain just the file name and the first the directory where the file is located.
With this correction your code should work :
File pdffile=new File(Environment.getExternalStorageDirectory(),"abc.pdf");

Eclipse Android App - The Application has stopped unexpectedly. Please try again

I have problem with my application for android (TelephonyManager Service). When I run app with code without getters it works, but if I use get() function app send me a message "The Application has stopped unexpectedly. Please try again". I really don't know what's wrong.
My "bad" code:
package com.example.tc;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.telephony.TelephonyManager;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.os.Build;
public class TC1 extends ActionBarActivity {
TextView textView1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_tc1);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}
textView1=(TextView)findViewById(R.id.textView1);
//Get the instance of TelephonyManager
TelephonyManager tm=(TelephonyManager)getSystemService(Context.TELEPHONY_SERVICE);
//Calling the methods of TelephonyManager the returns the information
//If I remove this code app works
String IMEINumber=tm.getDeviceId();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.tc1, 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();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_tc1, container,
false);
return rootView;
}
}
}
Layout.activity_tc1.xml:
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.tc.TC1"
tools:ignore="MergeRootFrame" />
Layout.fragment_tc1.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="com.example.tc.TC1$PlaceholderFragment" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Phone Details:" />
<EditText
android:id="#+id/editText1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/textView1"
android:layout_centerHorizontal="true"
android:layout_marginTop="68dp"
android:ems="10"
android:text="aaaa" >
<requestFocus />
</EditText>
</RelativeLayout>
AndroidManifest.xml:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.tc"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="19" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.tc.TC1"
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>

The official documentation for getDeviceID says
Returns the unique device ID, for example, the IMEI for GSM and the MEID or ESN for CDMA phones. Return null if device ID is not available.
**Requires Permission: READ_PHONE_STATE**
You have not given that READ_PHONE_STATE permission in your manifest file.

ADD PERMISSION IN MANIFEST FILE
TelephonyManager tm = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
// get IMEI
String imei = tm.getDeviceId();
//get The Phone Number
String phone = tm.getLine1Number();
Manifest
<uses-permission android:name="android.permission.READ_PHONE_STATE" />

unfortunately API demo has stopped while running

I have developed an app for page navigation . when a button is clicked the page should navigate to the second page. when i run the project and opened my app its showing unfortunately API demo has stopped. I have posted the entire code of my app . PLS HELP ME OUT...
//MAIN ACTIVITY
<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" >
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="#+id/textView1"
android:layout_marginLeft="73dp"
android:layout_marginTop="14dp"
android:text="Click" />
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/button1"
android:layout_alignParentTop="true"
android:layout_marginLeft="14dp"
android:layout_marginTop="34dp"
android:text="Main Activity" />
</RelativeLayout>
//SECONDSCREEN ACTIVITY
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:orientation="vertical" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Sceond Screen Activity"
tools:context=".SecondScreenActivity"/>
</LinearLayout>
//JAVA CODE FOR MAIN ACTIVITY
package com.example.navigate;
import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
addButtonOnClickEventListener();
}
public void addButtonOnClickEventListener()
{
Button button = (Button)findViewById(R.id.button1);
final Context context = this;
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(context,SecondScreenActivity.class);
startActivity(intent);
}
});
}
#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;
}
}
// JAVA CODE FOR SECOND SCREEN ACTIVITY
package com.example.navigate;
import android.app.Activity;
public class SecondScreenActivity extends Activity {
}
// MANIFEST FILE
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.navigate"
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.navigate.SecondScreenActivity"
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>

First problem MainActivity is your launcher page here but you define the secondactivity as luncher in manifest.change it first.
Add an oncreate() to secondactivity otherwise there is nothing to show when the button click.
Third change your MainActivity Context to activity which is MainActivity.this not local
Other things are fine , and hope you understand your small problems..
Change your manifest to something like this:
// MANIFEST FILE
<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.navigate.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>
<activity android:name = ".SecondScreenActivity" />
</application>
And in your SecondScreenActivity add an oncreate method with the contet view like:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.secondactivity_layout);
}
And also in your mainactivity change the context to MainActivity.this . Here you define the context inside onclicklistener which links to your local method not the class.

Do android widgets require default activity to launch?

I searched a lot for this question and tried everything mentioned on the internet but still couldn't find a solution. My widget gets installed but does not update on clicking. I have not created a default activity for it.
My problem is that my action on clicking the button is not changing.
Here is my code:
//Android manifest
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.android.pictureapp"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="7"
android:targetSdkVersion="17" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<receiver android:name=".MyWidgetProvider" >
<intent-filter>
<action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
</intent-filter>
<meta-data
android:name="android.appwidget.provider"
android:resource="#xml/widget_info" />
</receiver>
<receiver
android:name="MyWidgetIntentReceiver"
android:exported="false" >
<intent-filter>
<action android:name="com.example.android.intent.action.CHANGE_PICTURE" />
</intent-filter>
<meta-data
android:name="android.appwidget.provider"
android:resource="#xml/widget_info" />
</receiver>
</application>
</manifest>
//MyWidgetProvider.java- this class contains the onUpdate method and has listeners.
package com.example.android.pictureapp;
import android.app.PendingIntent;
import android.appwidget.AppWidgetManager;
import android.appwidget.AppWidgetProvider;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.util.Log;
import android.widget.RemoteViews;
import com.example.android.pictureapp.R;
public class MyWidgetProvider extends AppWidgetProvider {
#Override
public void onUpdate(Context context, AppWidgetManager appWidgetManager,int[] appWidgetIds){
//Log.i("Tag","In onUpdate method");
System.out.println("Tag In onUpdate method");
RemoteViews views=new RemoteViews(context.getPackageName(),R.layout.widget_layout);
views.setOnClickPendingIntent(R.id.widget_button, buildButtonPendingIntent(context));
Log.i("Tag","Context value after setOnClickPI before pushWIDGET:"+context);
pushWidgetUpdate(context,views);
Log.i("Tag","after pushwidget update:"+context);
}
public static PendingIntent buildButtonPendingIntent(Context context){
Intent intent=new Intent();
intent.setAction("com.example.android.intent.action.CHANGE_PICTURE");
Log.i("Tag","intent's action:"+intent);
return PendingIntent.getBroadcast(context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
}
public static void pushWidgetUpdate(Context context,RemoteViews views){
System.out.println("Inside pushwidget");
ComponentName myWidget=new ComponentName(context, MyWidgetProvider.class);
AppWidgetManager manager=AppWidgetManager.getInstance(context);
manager.updateAppWidget(myWidget, views);
}
}
//MywidgetIntentReceiver.java - This class contains onReceive method and performs the function to do after clicking.
package com.example.android.pictureapp;
import com.example.android.pictureapp.R;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.util.Log;
import android.widget.RemoteViews;
public class MyWidgetIntentReceiver extends BroadcastReceiver {
private static int clickCount = 0;
#Override
public void onReceive(Context context, Intent intent) {
// Log.i("Tag1","In onReceive:"+intent);
System.out.println("In onReceive()");
if (intent.getAction().equals(
"com.example.android.intent.action.CHANGE_PICTURE")) {
updateWidgetPictureAndButtonListener(context);
}
}
private void updateWidgetPictureAndButtonListener(Context context) {
RemoteViews views = new RemoteViews(context.getPackageName(),
R.layout.widget_layout);
views.setImageViewResource(R.id.widget_image, getImageToSet());
System.out.println("in updateWidgetPicture method");
// Log.i("Tag","in updaeWIdgetPicture method");
// remember to set ur button click listeners
views.setOnClickPendingIntent(R.id.widget_button,
MyWidgetProvider.buildButtonPendingIntent(context));
MyWidgetProvider.pushWidgetUpdate(context.getApplicationContext(),
views);
}
private int getImageToSet() {
clickCount++;
Log.i("Tag", "in getImageToSet()" + clickCount);
return clickCount % 2 == 0 ? R.drawable.paypal_logo : R.drawable.paypaldonation;
}
}
//layout/widget_layout.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="wrap_content"
android:orientation="vertical"
android:layout_margin="5sp"
>
<ImageView
android:id="#+id/widget_image"
android:layout_width="110dp"
android:layout_height="110dp"
android:layout_gravity="center"
android:src="#drawable/paypal_logo"
/>
<Button
android:id="#+id/widget_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="Change it"
/>
</LinearLayout>
//xml/widget_info.xml
<?xml version="1.0" encoding="utf-8"?>
<appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
android:minWidth="146dp"
android:minHeight="146dp"
android:updatePeriodMillis="5000"
android:initialLayout="#layout/widget_layout"
>
</appwidget-provider>
//MainACtivity
package com.example.android.pictureapp;
import com.example.android.pictureapp.R;
import android.app.Activity;
import android.os.Bundle;
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;
}
}
And these are the changes to the manifest:
<activity
android:name="com.example.android.pictureapp.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>

Starting Android 3.1, your app must have at least one Activity that the user can launch before it will receive any broadcasts etc.
Since you don't have an Activity, your widget's broadcast probably isn't received because the system thinks your app is in a stopped state. Try adding an Activity.

Android Activity Breaking

I'm just trying to come up with a skeleton for an activity that uses a ListView as a news feed for a game my class is making.
In this activity there's simply the news feed, and a Refresh button (to update the ListView with the latest news)
My activity_news.xml:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_gravity="center">
<ListView
android:id="#+id/news"
android:layout_width="match_parent"
android:layout_height="320dp"
>
</ListView>
<Button
android:layout_width="fill_parent"
android:layout_height="45dp"
android:text="Refresh"
android:id="#+id/bRef"
/>
My NewsActivty.java:
package com.example.mynews;
import com.example.mynews.R;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
public class NewsActivity extends Activity {
Button refresh;
String newsfeed [] = {"latest news", "older news"};
Intent ref = new Intent(this, NewsActivity.class);
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_news);
refresh = (Button) findViewById(R.id.bRef);
ListView newsStuff = (ListView) findViewById(R.id.news);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, newsfeed);
newsStuff.setAdapter(adapter);
refresh.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
startActivity(ref);
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.news, menu);
return true;
}
}
And my manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.mynews"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.mynews.NewsActivity"
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>
I built everything up piece by piece and ran it as I finished something new (the layout, the array adapter, etc) and the activity started to break once I added the OnClickListener (emulator tells me "mynews has unfortunately stopped") for my Refresh button. I'm sure there's a better way to accomplish what i'm trying to do, but any assistance with what I have so far would be greatly appreciated.

Did u define a class ref.java?
if yes then you need define that activity(ref) in the manifest file.