Splash screen alpha animation not working - java

So I have an app that currently has two Activities. A SplashScreenActivity and a MainActivity. The transition between the two activities works just fine but the problem lies in the SplashScreenActivity itself. In it, there is a single ImageView that is supposed to be initially invisible and then fade in. But instead the image remains invisible the entire time. Please help. Here's the code:
The SplashScreenActivity:
package com.degioncloud;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.ImageView;
public class SplashScreenActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_splashscreen);
ImageView logo = (ImageView) findViewById(R.id.iv_logo);
logo.setImageAlpha(0);
logo.animate().alpha(1f).setDuration(1200).withEndAction(new Runnable() {
#Override
public void run() {
Intent i = new Intent(SplashScreenActivity.this, MainActivity.class);
startActivity(i);
overridePendingTransition(android.R.anim.fade_in,android.R.anim.fade_out);
finish();
}
});
}
}
The XML of the SplashScreenActivity:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
tools:context=".SplashScreenActivity">
<ImageView
android:id="#+id/iv_logo"
android:layout_width="200dp"
android:layout_height="200dp"
android:src="#mipmap/ic_launcher"
android:layout_centerInParent="true" />
</RelativeLayout>
My Manifest file:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.degioncloud">
<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/Theme.DegionCloud">
<activity android:name=".MainActivity" />
<activity android:name=".SplashScreenActivity"
android:theme="#style/SplashScreenTheme">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
The MainActivty is empty so I don't see a need to share that but if you need any other file then let me know and I will send a copy.

You need to call start() for the animation to begin:
logo.animate().alpha(1f).setDuration(1200).withEndAction(new Runnable() {
#Override
public void run() {
Intent i = new Intent(SplashScreenActivity.this, MainActivity.class);
startActivity(i);
overridePendingTransition(android.R.anim.fade_in,android.R.anim.fade_out);
finish();
}
}).start();

Related

My app keeps force closing when using 2 intents

Why do my android apps keep closing when using 2 intent? when I delete one of them, it's work. especially if I delete the "Reg" Button in the java files.
Thanks
XML Files:
<?xml version="1.0" encoding="utf-8"?>
<ScrollView 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"
tools:context=".LoginAct">
<TextView
android:id="#+id/daftar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:text="#string/daftar"
android:textAlignment="center"
android:textColor="#color/Linktext"
android:clickable="true"
android:focusable="true"
android:layout_marginTop="10dp">
</TextView>
<Button
android:id="#+id/pass"
android:layout_width="wrap_content"
android:layout_height="23dp"
android:layout_gravity="center_horizontal"
android:layout_marginTop="25dp"
android:background="#color/colorPrimaryDark"
android:clickable="true"
android:focusable="true"
android:text="#string/lewat"
android:textColor="#color/textwhite" />
Java Files (If I deleted the "Reg" Button from this file, the app is working, but otherwise it will force close after the splash screen):
package com.soerja.ngalamhistory;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
public class LoginAct extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.act_login);
Button Pass = (Button) findViewById(R.id.pass);
Button Reg = (Button) findViewById(R.id.daftar);
Pass.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent = new Intent(LoginAct.this, MainActivity.class);
startActivity(intent);
}
});
Reg.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent = new Intent(LoginAct.this, RegisAct.class);
startActivity(intent);
}
});
}
}
AndroidManifest Files:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.soerja.ngalamhistory">
<application
android:allowBackup="true"
android:icon="#mipmap/logo"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity
android:name=".SplashAct"
android:theme="#style/SplashTheme">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".LoginAct"
android:label="#string/applogin"
android:theme="#style/LogTheme"></activity>
<activity
android:name=".MainActivity"
android:label="#string/home"
android:theme="#style/AppTheme"></activity>
<activity android:name=".RegisAct"
android:label="#string/appdaftar"
android:theme="#style/LogTheme"></activity>
</application>
</manifest>
I would really appreciate your help because this is my school project :)
You are casting a TextView into a Button. Probably the problem is a invalid cast exception.
In XML, you define the "daftar" as a TextView, but in java you are trying to use it as a Button.
Change it
Button Reg = (Button) findViewById(R.id.daftar);
To it
TextView Reg = (TextView) findViewById(R.id.daftar);
Or change your XML implamentation, defining "daftar" as a Button
here you are using your text view id
android:id="#+id/daftar"
as a reference to declaring button
Button Reg = (Button) findViewById(R.id.daftar);
so i think ,that may be the reason for crash
try this method :
add this in your text xml code:
android:onClick="daftar"
add for java class use this:
public void daftar(View v)
{
Intent intent = new Intent(this, RegisAct.class);
startActivity(intent);
}
and remove the old java code you used for this text view:
i hope this helps.

Exoplayer playing audio even when the PlayerView has been paused

I'm creating an Exoplayer video player which plays a mp4 file containing video and audio from a url. The video and audio plays properly but when the video player is paused, the audio is still being played. I don't know how I can fix this. I'm assuming that the problem occurs due to my android device. I'm leaving my code, app's info, android device info below and a video clip of my problem. If someone can use my code and tell me if they are experiencing the same problem, it will be thankful. Please Help Me.
The app's detail:
Using API 21: Android 5.0 (Lollipop). Contains Internet Permission. Importing implementation 'com.google.android.exoplayer:exoplayer:2.8.1'.
Device detail:
Type: Android Tablet. Android Version : 5.1.1
The MainActivity.java:
import android.content.pm.ActivityInfo;
import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import com.google.android.exoplayer2.C;
import com.google.android.exoplayer2.ExoPlayerFactory;
import com.google.android.exoplayer2.Format;
import com.google.android.exoplayer2.SimpleExoPlayer;
import com.google.android.exoplayer2.source.ConcatenatingMediaSource;
import com.google.android.exoplayer2.source.ExtractorMediaSource;
import com.google.android.exoplayer2.source.MediaSource;
import com.google.android.exoplayer2.source.MergingMediaSource;
import com.google.android.exoplayer2.source.SingleSampleMediaSource;
import com.google.android.exoplayer2.trackselection.AdaptiveTrackSelection;
import com.google.android.exoplayer2.trackselection.DefaultTrackSelector;
import com.google.android.exoplayer2.trackselection.TrackSelection;
import com.google.android.exoplayer2.ui.PlayerView;
import com.google.android.exoplayer2.upstream.DataSource;
import com.google.android.exoplayer2.upstream.DefaultBandwidthMeter;
import com.google.android.exoplayer2.upstream.DefaultDataSourceFactory;
import com.google.android.exoplayer2.util.MimeTypes;
import com.google.android.exoplayer2.util.Util;
import java.util.ArrayList;
public class MainActivity extends AppCompatActivity
{
SimpleExoPlayer video_player;
PlayerView player_screen;
DefaultTrackSelector track_selector;
DefaultBandwidthMeter band_width_meter = new DefaultBandwidthMeter();
MediaSource mediaSource_both;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
player_screen = findViewById (R.id.player_screen);
player_screen.requestFocus();
TrackSelection.Factory video_track_selection_factory = new AdaptiveTrackSelection.Factory(band_width_meter);
track_selector = new DefaultTrackSelector(video_track_selection_factory);
video_player = ExoPlayerFactory.newSimpleInstance(this, track_selector);
player_screen.setPlayer(video_player);
video_player.setPlayWhenReady(true);
DataSource.Factory data_source_factory = new DefaultDataSourceFactory(this, Util.getUserAgent(this, "Application Name"), new DefaultBandwidthMeter());
Uri url = Uri.parse("http://dash.akamaized.net/akamai/bbb/bbb_1280x720_60fps_6000k.mp4");
mediaSource_both = new ExtractorMediaSource.Factory(data_source_factory).createMediaSource(url);
video_player.prepare(mediaSource_both);
}
}
The activity_main.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"
tools:context=".MainActivity">
<com.google.android.exoplayer2.ui.PlayerView
android:id="#+id/player_screen"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_gravity="center"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:use_controller="true" />
</android.support.constraint.ConstraintLayout>
Video Clip of the problem (The video has been uploaded on OpenLoad server):
https://openload.co/embed/NrlMUxUP0C4/problem.mp4
I made a very easy sample app to reproduce the issue
but yet too see any problem neither with the player or video
here is the code:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
SimpleExoPlayerView simpleExoPlayerView = findViewById(R.id.player_view);
SimpleExoPlayer player = ExoPlayerFactory.newSimpleInstance(this, new DefaultTrackSelector(new DefaultBandwidthMeter.Builder().build()));
SimpleCache downloadCache = new SimpleCache(new File(getCacheDir(), "exoCache"), new NoOpCacheEvictor());
String uri = "http://dash.akamaized.net/akamai/bbb/bbb_1280x720_60fps_6000k.mp4";
DataSource.Factory dataSourceFactory = new CacheDataSourceFactory(downloadCache, new DefaultDataSourceFactory(this, "seyed"));
MediaSource mediaSource = new ExtractorMediaSource.Factory(dataSourceFactory).createMediaSource(Uri.parse(uri));
player.addListener(new Player.EventListener() {
#Override
public void onTimelineChanged(Timeline timeline, Object manifest, int reason) {
Log.d("exo", "timeLine Changed");
}
#Override
public void onTracksChanged(TrackGroupArray trackGroups, TrackSelectionArray trackSelections) {
}
#Override
public void onLoadingChanged(boolean isLoading) {
Log.d("exo", "loding changed= " + isLoading);
}
#Override
public void onPlayerStateChanged(boolean playWhenReady, int playbackState) {
Log.d("exo", "state changed");
}
#Override
public void onRepeatModeChanged(int repeatMode) {
}
#Override
public void onShuffleModeEnabledChanged(boolean shuffleModeEnabled) {
}
#Override
public void onPlayerError(ExoPlaybackException error) {
Log.e("exo", "exoplayer error", error);
}
#Override
public void onPositionDiscontinuity(int reason) {
}
#Override
public void onPlaybackParametersChanged(PlaybackParameters playbackParameters) {
}
#Override
public void onSeekProcessed() {
Log.d("exo", "seek processed");
}
});
player.prepare(mediaSource);
simpleExoPlayerView.setPlayer(player);
player.setPlayWhenReady(true);
}
here is the layout:
<android.support.design.widget.CoordinatorLayout 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"
tools:context=".MainActivity">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/AppTheme.AppBarOverlay">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:popupTheme="#style/AppTheme.PopupOverlay" />
</android.support.design.widget.AppBarLayout>
<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"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
tools:context=".MainActivity"
tools:showIn="#layout/activity_main">
<com.google.android.exoplayer2.ui.SimpleExoPlayerView
android:id="#+id/player_view"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</android.support.constraint.ConstraintLayout>
manifest:
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
<uses-permission android:name="android.permission.INTERNET" />
<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=".MainActivity"
android:label="#string/app_name"
android:theme="#style/AppTheme.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<service android:name=".MyDownloadService"
android:exported="false"/>
</application>
and lastly the build gradle file:
dependencies {
implementation 'com.android.support:appcompat-v7:27.0.2'
implementation 'com.android.support.constraint:constraint-layout:1.0.2'
implementation 'com.android.support:design:27.0.2'
implementation 'com.google.android.exoplayer:exoplayer:2.8.2'
}
Update 17/18/2018
Actually the problem you are facing is because of this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE); line.
when you run your activity it starts in portrait mode and everything is fine (without this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);) and one exoplayer is created and starts the playback.
but when you change the orientation during startup of the activity. android trys to destroy the activity and create another one here comes your problem:
first activity does not get destroyed because you forget to realease the ExoPlayer in onDestroy() and when the new activity is created a new exoplayer is also created and both of them keep the playback going. when you pause the playback you actually pausing the second one not the first one. this behavior is called memory leak.
first of all make sure you call .release() in onDestroy() of the activity.
and then for orientation you have couple of options:
1.specify the orientation of the activity in the manifest so android apply it before the creation of the activity
<activity
android:name=".MainActivity"
android:label="#string/app_name"
android:theme="#style/AppTheme.NoActionBar"
android:screenOrientation="sensorLandscape">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
2.prevent android from killing the activity on config changes:
<activity
android:name=".MainActivity"
android:label="#string/app_name"
android:theme="#style/AppTheme.NoActionBar"
android:configChanges="orientation">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
hope it helps you
you can also chek out this sample (with a small and minor difference) on github:

Android Studio can't find class Button

This is AndroidManifest.XML
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="activitytest.example.com.activitytest">
<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=".FirstActivity"
android:label="This is FirstActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>
</application>
This is FirstActivity.java
package activitytest.example.com.activitytest;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;
public class FirstActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.first_layout);
Button button1 = (Button) findViewById(R.id.button_1);
button1.setOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View v){
Toast.makeText(FirstActivity.this,"You clicked Button 1",
Toast.LENGTH_SHORT).show();
}
});
}
}
The error is on this:
Button button1 = (Button) findViewById(R.id.button_1);
can't find Button class ,how can I fix this?
This is fisrt_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<Button
android:id="#+id/button_1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Button_1" />
This is my first time study Android, help me please.Thank you.
You do not have import android.widget.Button in your FirstActivity class.
This happens because you have to add the import line in your Activity class. Add this line:
import android.widget.Button

Splash screen activity not working

Hi have created splash screen as a separate project by using this link : http://www.androidhive.info/2013/07/how-to-implement-android-splash-screen-2/ . And it did worked on my emulator . However, when I implemented this in my app. It did not worked . I don' know whats wrong with my code. My main.java, splash screen.java and splash.xml are the following. Please note that I did define my activity in manifest file. Any help will be greatly appreciated...
MainActivity.Java
import android.app.Activity;
import android.content.Intent;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
public class MainActivity extends Activity implements OnClickListener {
private MediaPlayer mp;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setVolumeControlStream(AudioManager.STREAM_MUSIC);
findViewById(R.id.button_1).setOnClickListener(this);
findViewById(R.id.button_2).setOnClickListener(this);
findViewById(R.id.button_3).setOnClickListener(this);
}
public void onClick(View v) {
int resId=1;
// Release any resources from previous MediaPlayer
if (mp != null) {
mp.release();
}
switch (v.getId()) {
case R.id.button_1: resId = R.raw.button_1; break;
case R.id.button_2: resId = R.raw.button_2; break;
case R.id.button_3:
startActivity(new Intent(MainActivity.this,SecondActivity.class));
return;
}
// Create a new MediaPlayer to play this sound
mp = MediaPlayer.create(this, resId);
mp.start();
}
}
SplashScreen.java
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
public class SplashScreen extends Activity {
// Splash screen timer
private static int SPLASH_TIME_OUT = 3000;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_splash);
new Handler().postDelayed(new Runnable() {
/*
* Showing splash screen with a timer. This will be useful when you
* want to show case your app logo / company
*/
#Override
public void run() {
// This method will be executed once the timer is over
// Start your app main activity
Intent i = new Intent(SplashScreen.this, MainActivity.class);
startActivity(i);
// close this activity
finish();
}
}, SPLASH_TIME_OUT);
}
}
activity_splash.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#drawable/gradient_background" >
<ImageView
android:id="#+id/imgLogo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:adjustViewBounds="true"
android:scaleType="fitXY"
android:src="#drawable/images235" />
</RelativeLayout>
Android Manifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.Smit.yourbollywoodyourplaylist"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="11" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="info.androidhive.androidsplashscreentimer.SplashScreen"
android:label="#string/app_name"
android:screenOrientation="portrait"
android:theme="#android:style/Theme.Black.NoTitleBar" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".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=".SecondActivity"
android:label="#string/app_name"/>
</application>
</manifest>
It's not clear which package your SplashScreen.java lives in, but
android:name="info.androidhive.androidsplashscreentimer.SplashScreen"
might need to be changed to
android:name=".SplashScreen"
You may have just pasted in the manifest definition from the sample project without adjusting the activity name to match your own project.

NullPointerException while creating activity

this is my codes LoginActivity.java file
package com.example.crims;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.View;
import android.widget.TextView;
public class LoginActivity extends Activity {
TextView screen;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
screen = (TextView) findViewById(R.id.link_to_register);
// Listening to register new account link
screen.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// Switching to Register screen
Intent i = new Intent(getApplicationContext(), RegisterActivity.class);
startActivity(i);
}
});
}
}
this is my code for 'activity_login.xml' file
<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=".LoginActivity" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/hello_world" />
</RelativeLayout>`
And Finally this is my menifest file
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.crims"
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.crims.LoginActivity"
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=".RegisterActivity"
android:label="Register New Account">
</activity>
</application>
</manifest>
All of these files are here and i want to find my error as I m new to android app development...
You have NullPointerException(NPE) here:
10-01 21:02:07.580: E/AndroidRuntime(1299):
at com.example.crims.LoginActivity.onCreate(LoginActivity.java:17)
So, check line 17 of LoginActivity.java (you can just double click on this message in the logcat view and you will be navigated to this line).
It seems, line 17 is this:
registerScreen.setOnClickListener(new View.OnClickListener() {
As this is NPE, registerScreen is null. So, you should inspect why it is null. This is because Activity can't find it in line above and it returns null instead:
TextView registerScreen = (TextView) findViewById(R.id.link_to_register);
This can be one of two possibilities: either you do not have widget with id 'link_to_register' in activity_login.xml, or something other is wrong :)
Check this please and show your activity_login.xml file, please.
Listen brother take this code. Change it according to you.
public class MainActivity extends Activity {
TextView screen;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
screen = (TextView) findViewById(R.id.screen);
// Listening to register new account link
screen.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// Switching to Register screen
Intent i = new Intent(getApplicationContext(), Register.class);
startActivity(i);
}
});
}
}
You need to register your activity in manifest.xml file too in case if you don't know about it.

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