Below i have pasted copy of my java,xml and logcat of the application.
Here goes my java code
package my.example.myproject;
import my.example.myproject.util.SystemUiHider;
import android.annotation.TargetApi;
import android.app.Activity;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Button;
/**
* An example full-screen activity that shows and hides the system UI (i.e.
* status bar and navigation/system bar) with user interaction.
*
* @see SystemUiHider
*/
public class FullscreenActivity extends Activity {
/**
* Whether or not the system UI should be auto-hidden after
* {@link #AUTO_HIDE_DELAY_MILLIS} milliseconds.
*/
private static final boolean AUTO_HIDE = true;
/**
* If {@link #AUTO_HIDE} is set, the number of milliseconds to wait after
* user interaction before hiding the system UI.
*/
private static final int AUTO_HIDE_DELAY_MILLIS = 3000;
/**
* If set, will toggle the system UI visibility upon interaction. Otherwise,
* will show the system UI visibility upon interaction.
*/
private static final boolean TOGGLE_ON_CLICK = true;
/**
* The flags to pass to {@link SystemUiHider#getInstance}.
*/
private static final int HIDER_FLAGS = SystemUiHider.FLAG_HIDE_NAVIGATION;
/**
* The instance of the {@link SystemUiHider} for this activity.
*/
private SystemUiHider mSystemUiHider;
Button iol,help,about;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_fullscreen);
final View controlsView = findViewById(R.id.fullscreen_content_controls);
iol = (Button)findViewById(R.id.iolCalculation);
help = (Button)findViewById(R.id.sHelp);
about = (Button)findViewById(R.id.sAbout);
Thread iolthread=new Thread(){
public void run(){
try{
iol.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
setContentView(R.layout.selection);
}
});
Intent iolIntent=new Intent(FullscreenActivity.this,Selection.class);
startActivity(iolIntent);
}
finally{
finish();
}
}
};
iolthread.start();
// Set up an instance of SystemUiHider to control the system UI for
// this activity.
mSystemUiHider = SystemUiHider.getInstance(this, controlsView,
HIDER_FLAGS);
mSystemUiHider.setup();
mSystemUiHider
.setOnVisibilityChangeListener(new SystemUiHider.OnVisibilityChangeListener() {
// Cached values.
int mControlsHeight;
int mShortAnimTime;
@Override
@TargetApi(Build.VERSION_CODES.HONEYCOMB_MR2)
public void onVisibilityChange(boolean visible) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR2) {
// If the ViewPropertyAnimator API is available
// (Honeycomb MR2 and later), use it to animate the
// in-layout UI controls at the bottom of the
// screen.
if (mControlsHeight == 0) {
mControlsHeight = controlsView.getHeight();
}
if (mShortAnimTime == 0) {
mShortAnimTime = getResources().getInteger(
android.R.integer.config_shortAnimTime);
}
controlsView
.animate()
.translationY(visible ? 0 : mControlsHeight)
.setDuration(mShortAnimTime);
} else {
// If the ViewPropertyAnimator APIs aren't
// available, simply show or hide the in-layout UI
// controls.
controlsView.setVisibility(visible ? View.VISIBLE
: View.GONE);
}
if (visible && AUTO_HIDE) {
// Schedule a hide().
delayedHide(AUTO_HIDE_DELAY_MILLIS);
}
}
});
// Set up the user interaction to manually show or hide the system UI.
controlsView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (TOGGLE_ON_CLICK) {
mSystemUiHider.toggle();
} else {
mSystemUiHider.show();
}
}
});
// Upon interacting with UI controls, delay any scheduled hide()
// operations to prevent the jarring behavior of controls going away
// while interacting with the UI.
}
@Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
// Trigger the initial hide() shortly after the activity has been
// created, to briefly hint to the user that UI controls
// are available.
delayedHide(100);
}
/**
* Touch listener to use for in-layout UI controls to delay hiding the
* system UI. This is to prevent the jarring behavior of controls going away
* while interacting with activity UI.
*/
View.OnTouchListener mDelayHideTouchListener = new View.OnTouchListener() {
@Override
public boolean onTouch(View view, MotionEvent motionEvent) {
if (AUTO_HIDE) {
delayedHide(AUTO_HIDE_DELAY_MILLIS);
}
return false;
}
};
Handler mHideHandler = new Handler();
Runnable mHideRunnable = new Runnable() {
@Override
public void run() {
mSystemUiHider.hide();
}
};
/**
* Schedules a call to hide() in [delay] milliseconds, canceling any
* previously scheduled calls.
*/
private void delayedHide(int delayMillis) {
mHideHandler.removeCallbacks(mHideRunnable);
mHideHandler.postDelayed(mHideRunnable, delayMillis);
}
}
XML
<FrameLayout 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:background="@color/black"
tools:context=".FullscreenActivity"
android:id="@+id/frame_layout">
<LinearLayout
android:id="@+id/fullscreen_content_controls"
style="?buttonBarStyle"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom|center_horizontal"
android:background="@color/black_overlay"
android:orientation="horizontal"
tools:ignore="UselessParent" >
</LinearLayout>
<Button
style="@style/ButtonBarButton"
android:layout_width="222dp"
android:layout_height="62dp"
android:layout_marginLeft="45dp"
android:layout_marginTop="75dp"
android:background="@color/black"
android:paddingLeft="20dp"
android:id="@+id/iolCalculation"
android:text="@string/Button"
android:textColor="@color/WhiteSmoke"
android:textStyle="bold" />
<Button
style="@style/ButtonBarButton"
android:layout_width="222dp"
android:layout_height="62dp"
android:layout_marginLeft="45dp"
android:id="@+id/sHelp"
android:layout_marginTop="139dp"
android:background="@color/Black"
android:gravity="center"
android:paddingLeft="10dp"
android:text="@string/Button1"
android:textColor="@color/WhiteSmoke"
android:textStyle="bold" />
<Button
style="@style/ButtonBarButton"
android:layout_width="222dp"
android:layout_height="62dp"
android:id="@+id/sAbout"
android:layout_marginLeft="45dp"
android:layout_marginTop="203dp"
android:background="@color/Black"
android:paddingLeft="10dp"
android:text="@string/Button2"
android:textColor="@color/WhiteSmoke"
android:textStyle="bold" >
</Button>
</FrameLayout>
logcat
12-16 10:48:26.975: E/Trace(767): error opening trace file: No such file or directory (2)
12-16 10:51:38.199: E/AndroidRuntime(767): FATAL EXCEPTION: main
12-16 10:51:38.199: E/AndroidRuntime(767): java.lang.NullPointerException
12-16 10:51:38.199: E/AndroidRuntime(767): at com.android.internal.widget.ActionBarView$3.onClick(ActionBarView.java:168)
12-16 10:51:38.199: E/AndroidRuntime(767): at android.view.View.performClick(View.java:4202)
12-16 10:51:38.199: E/AndroidRuntime(767): at android.view.View$PerformClick.run(View.java:17340)
12-16 10:51:38.199: E/AndroidRuntime(767): at android.os.Handler.handleCallback(Handler.java:725)
12-16 10:51:38.199: E/AndroidRuntime(767): at android.os.Handler.dispatchMessage(Handler.java:92)
12-16 10:51:38.199: E/AndroidRuntime(767): at android.os.Looper.loop(Looper.java:137)
12-16 10:51:38.199: E/AndroidRuntime(767): at android.app.ActivityThread.main(ActivityThread.java:5039)
12-16 10:51:38.199: E/AndroidRuntime(767): at java.lang.reflect.Method.invokeNative(Native Method)
12-16 10:51:38.199: E/AndroidRuntime(767): at java.lang.reflect.Method.invoke(Method.java:511)
12-16 10:51:38.199: E/AndroidRuntime(767): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
12-16 10:51:38.199: E/AndroidRuntime(767): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
12-16 10:51:38.199: E/AndroidRuntime(767): at dalvik.system.NativeStart.main(Native Method)
i have tried every possible solution in stackoverflow but in vain.help me. I think mostly there is a problem in xml to java display content.Also do i need to put in id for every layout in xml and how does the java code detect the layout to be displayed
here goes my selection java code and xml
package com.example.iolcalci;
import android.app.Activity;
import android.os.Bundle;
public class Selection extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.selective);
}
}
<?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="@color/black"
android:orientation="vertical" >
<Spinner
android:id="@+id/formulae"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="50dp"
android:layout_marginRight="50dp"
android:background="@color/LightSkyBlue"
android:prompt="@string/prompt"
android:entries="@array/formulas" />
<TextView
android:id="@+id/k2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignRight="@+id/k1"
android:layout_below="@+id/k1"
android:layout_marginTop="38dp"
android:text="@string/K2"
android:textColor="@color/White"
android:textSize="25sp" />
<TextView
android:id="@+id/al_const"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/al"
android:layout_below="@+id/al"
android:layout_marginTop="44dp"
android:text="@string/Rx"
android:textColor="@color/White"
android:textSize="20sp" />
<TextView
android:id="@+id/al"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignRight="@+id/k2"
android:layout_below="@+id/k2"
android:layout_marginTop="38dp"
android:text="@string/AL"
android:textColor="@color/White"
android:textSize="25sp" />
<EditText
android:id="@+id/k2_editText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="@+id/al"
android:layout_alignRight="@+id/al_editText"
android:layout_alignTop="@+id/k2"
android:layout_marginLeft="120dp"
android:background="@color/black"
android:ems="10"
android:inputType="numberDecimal"
android:textColorLink="@color/white" />
<EditText
android:id="@+id/al_editText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignRight="@+id/formulae"
android:layout_alignTop="@+id/al"
android:layout_marginLeft="120dp"
android:ems="10"
android:inputType="numberDecimal" />
<EditText
android:id="@+id/al_const_editText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/al_const"
android:layout_alignRight="@+id/al_editText"
android:layout_marginLeft="120dp"
android:ems="10"
android:inputType="numberDecimal" />
<Button
android:id="@+id/result"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:background="@color/LightSkyBlue"
android:text="@string/Result" />
<EditText
android:id="@+id/k1_editText"
android:layout_width="wrap_content"
android:layout_height="37dp"
android:layout_alignLeft="@+id/k2_editText"
android:layout_alignRight="@+id/formulae"
android:layout_below="@+id/formulae"
android:layout_marginTop="30dp"
android:background="@color/black"
android:ems="10"
android:inputType="numberDecimal"
android:textColorLink="@color/White" />
<TextView
android:id="@+id/k1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/k1_editText"
android:layout_alignParentLeft="true"
android:layout_marginLeft="27dp"
android:text="@string/K1"
android:textColor="@color/white"
android:textSize="25sp" />
</RelativeLayout>
THE NEW LOGCAT
12-21 10:44:50.419: W/Trace(766): Unexpected value from nativeGetEnabledTags: 0
12-21 10:44:50.573: W/Trace(766): Unexpected value from nativeGetEnabledTags: 0
12-21 10:44:50.573: W/Trace(766): Unexpected value from nativeGetEnabledTags: 0
12-21 10:44:50.923: D/AndroidRuntime(766): Shutting down VM
12-21 10:44:50.923: W/dalvikvm(766): threadid=1: thread exiting with uncaught exception (group=0x40a70930)
12-21 10:44:50.933: E/AndroidRuntime(766): FATAL EXCEPTION: main
12-21 10:44:50.933: E/AndroidRuntime(766): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.iolcalci/com.example.iolcalci.MainActivity}: java.lang.NullPointerException
12-21 10:44:50.933: E/AndroidRuntime(766): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
12-21 10:44:50.933: E/AndroidRuntime(766): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
12-21 10:44:50.933: E/AndroidRuntime(766): at android.app.ActivityThread.access$600(ActivityThread.java:141)
12-21 10:44:50.933: E/AndroidRuntime(766): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
12-21 10:44:50.933: E/AndroidRuntime(766): at android.os.Handler.dispatchMessage(Handler.java:99)
12-21 10:44:50.933: E/AndroidRuntime(766): at android.os.Looper.loop(Looper.java:137)
12-21 10:44:50.933: E/AndroidRuntime(766): at android.app.ActivityThread.main(ActivityThread.java:5039)
12-21 10:44:50.933: E/AndroidRuntime(766): at java.lang.reflect.Method.invokeNative(Native Method)
12-21 10:44:50.933: E/AndroidRuntime(766): at java.lang.reflect.Method.invoke(Method.java:511)
12-21 10:44:50.933: E/AndroidRuntime(766): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
12-21 10:44:50.933: E/AndroidRuntime(766): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
12-21 10:44:50.933: E/AndroidRuntime(766): at dalvik.system.NativeStart.main(Native Method)
12-21 10:44:50.933: E/AndroidRuntime(766): Caused by: java.lang.NullPointerException
12-21 10:44:50.933: E/AndroidRuntime(766): at com.example.iolcalci.MainActivity.onCreate(MainActivity.java:23)
12-21 10:44:50.933: E/AndroidRuntime(766): at android.app.Activity.performCreate(Activity.java:5104)
12-21 10:44:50.933: E/AndroidRuntime(766): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
12-21 10:44:50.933: E/AndroidRuntime(766): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
12-21 10:44:50.933: E/AndroidRuntime(766): ... 11 more
Manifest file
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.iolcalci"
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.iolcalci.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="Selection"
android:exported="false"
android:configChanges="orientation|keyboardHidden|screenSize"
android:label="@string/app_name">
<intent-filter>
<action android:name="com.example.iolcalci.MAIN" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
</application>
</manifest>
