For my project I have to have two .java classes and two .xml files. The first one that I have created is SplashActivity.java. After I have created that class, put some code in there, and worked with my activity_splash.xml. I needed to create the MainActivity.java class. I went into the
AndroidManifest.xml -> Application -> Add -> Actiivity. Name ->
.MainActivity
In my MainActivity.java class I write an onCreate() method to create the activity_main.xml. However, my eclipse emulator underlines the activity_main with a red underline. When I move my mouse to it, it gives me several options "Create filed "activity_main" in type layout", "Create constant "activity_main" in type layout". I am not sure which ones of those are correct way to fix the issue that's why I decided not to mess with R.java. But I am confused why I have that error because as far as I am concerned my code is correct.
The following are the codes:
SplashActivity.java
package com.example.easternmusic;
import java.util.Timer;
import java.util.TimerTask;
import android.app.Activity;
import android.app.ActionBar;
import android.app.Fragment;
import android.content.Intent;
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.os.Build;
public class SplashActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_splash);
TimerTask task = new TimerTask() {
#Override
public void run() {
// TODO Auto-generated method stub
finish();
startActivity(new
Intent(SplashActivity.this,MainActivity.class));
}
};
Timer opening = new Timer ();
opening.schedule(task, 5000);
if (savedInstanceState == null) {
getFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.splash, 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_splash,
container, false);
return rootView;
}
}
}
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.easternmusic"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="19"
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.easternmusic.SplashActivity"
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=".MainActivity"></activity>
</application>
</manifest>
MainActivity.java
package com.example.easternmusic;
import android.app.Activity;
import android.app.ActionBar;
import android.app.Fragment;
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.os.Build;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
}
Each activity consist of a layout(xml file) and a java class. Here you create the class MainActivity but you forget to add layout of the activity i.e xml file.when you write this setContentView(R.layout.activity_main);. its mean you are setting layout here.Activity_main is the name of the layout file.which you dont add in your layout folder. So the answer to this question is go to your layout folder and add xml file with name activity_main. Your problem will be solved.
Related
I am new to android app development. I am practicing some basics with a simple app. I was able to launch an activity from my app's home screen, however, when I try to launch a third
activity from activity2 using the same method, the app fails to work.
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_fish);
Button anthiasButton = (Button)findViewById(R.id.anthiasButton);
anthiasButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0) {
Intent intent = new Intent(FishActivity.this, AnthiasActivity.class);
startActivity(intent);
}
});
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}
}
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.kdc.reeffishguide"
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.kdc.reeffishguide.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="com.kdc.reeffishguide.FishActivity"
android:label="#string/title_activity_fish" >
</activity>
<activity
android:name="com.kdc.reeffishguide.CoralActivity"
android:label="#string/title_activity_coral" >
</activity>
<activity
android:name="com.kdc.reeffishguide.InvertsActivity"
android:label="#string/title_activity_inverts" >
</activity>
<activity
android:name="com.kdc.reeffishguide.AnthiasActivity"
android:label="#string/title_activity_anthias" >
</activity>
</application>
</manifest>
I am trying to open AnthiasActivity from FishActivity. No errors or warnings are given in eclipse, but when I run the app and click on FishActivity the app closes. When I delete the portion of code in fish activity that is responsible for launching anthias Activity, fish activity opens, but obviously I cannot get to Anthias Activity
package com.kdc.reeffishguide;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
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.os.Build;
public class AnthiasActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_anthias);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.anthias, 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_anthias,
container, false);
return rootView;
}
}
}
here are the logcat errors.
04-12 19:24:32.427: E/QcrilMsgTunnelSocket(22517): IOExceptionjava.io.IOException: No such file or directoryReason: No such file or directory
04-12 19:24:36.421: E/QcrilMsgTunnelSocket(22517): IOExceptionjava.io.IOException: No such file or directoryReason: No such file or directory
04-12 19:24:40.425: E/QcrilMsgTunnelSocket(22517): IOExceptionjava.io.IOException: No such file or directoryReason: No such file or directory
my app force closes I do not know why. All it should do is vibrating when it is in the foreground and stop if it is not but when I start it on my phone it force closes. I added lines about vibrator usage into the manifest by hand. Maybe this is the problem. I have to anything else with it to be valid for the app?
My manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.kevinboonemidi"
android:versionCode="1"
android:versionName="1.0" >
<permission android:name="android.permission.VIBRATE" ></permission>
<uses-permission android:name="android.permission.VIBRATE"/>
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="8" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.haptic.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>
My code:
package com.example.haptic_sof;
import java.io.File;
import java.io.FileDescriptor;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import com.example.kevinboonemidi.R;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.os.Vibrator;
import android.app.Activity;
import android.content.Context;
import android.view.Menu;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnTouchListener;
public class MainActivity extends Activity
{
protected Vibrator v = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
long pwmCycles[];
pwmCycles = new long[4];
v = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
long[] pattern = { 0, 200, 10 };
v.vibrate(pattern, 0);
}
#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;
}
protected void onPause(){
super.onPause();
v.cancel();
}
protected void onStop()
{
super.onStop();
v.cancel();
}
}
Your packages are a mess.
You define com.example.kevinboonemidi as your package in the manifest, declare your Activity to be in com.example.haptic and actually put your Activity in com.example.haptic_sof.
Change android:name="com.example.haptic.MainActivity" to android:name="com.example.haptic_sof.MainActivity" and your app should run, though you may need to end up using one package entirely at least to start with.
It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.
Closed 10 years ago.
This is the coding for my application, and I am using Eclipse.
DisplayMessageActivity.java
package com.example.myfirstapp;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.NavUtils;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
#SuppressLint("NewApi") public class DisplayMessageActivity extends Activity
{
#SuppressLint("NewApi") #Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_display_message);
// Show the Up button in the action bar.
getActionBar().setDisplayHomeAsUpEnabled(true);
//Get the message from the intent
Intent intent = getIntent();
String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
//Create the text view
TextView textView = new TextView(this);
textView.setTextSize(40);
textView.setText(message);
//Set the text view
setContentView(textView);
}
// OKAY TO REMOVE
#Override
public boolean onCreateOptionsMenu(Menu menu)
{
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_display_message, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item)
{
switch (item.getItemId())
{
case android.R.id.home:
// This ID represents the Home or Up button. In the case of this
// activity, the Up button is shown. Use NavUtils to allow users
// to navigate up one level in the application structure. For
// more details, see the Navigation pattern on Android Design:
//
// http://developer.android.com/design/patterns/navigation.html#up-vs-back
//
NavUtils.navigateUpFromSameTask(this);
return true;
}
return super.onOptionsItemSelected(item);
}
}
MyFirstAppManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.myfirstapp"
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" android:debuggable="true">
<activity
android:name="com.example.myfirstapp.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="com.example.myfirstapp.DisplayMessageActivity"
android:label="#string/title_activity_display_message"
android:parentActivityName="com.example.myfirstapp.MainActivity" >
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.myfirstapp.MainActivity" />
</activity>
</application>
</manifest>
MainActivity.java
package com.example.myfirstapp;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
public class MainActivity extends Activity
{
public final static String EXTRA_MESSAGE = "com.example.myfirstapp.MESSAGE";
#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.activity_main, menu);
return true;
}
/** Called when the user clicks the Send button */
public void sendMessage (View view)
{
// Do something in response to button
Intent intent = new Intent(this, DisplayMessageActivity.class);
EditText editText = (EditText) findViewById(R.id.edit_message);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE, message);
startActivity(intent);
}
}
If you need more information or debug results, please let me know. I am following the Android Developer Tutorial located here.
Without the LogCat, I can address one problem with your code. #SuppressLint("NewApi"). Lint makes a good point - your target API is 8. Froyo and Gingerbread don't have an Action Bar.
Now, in DisplayMessageActivity make a method like this:
#TargetApi(Build.VERSION_CODES.HONEYCOMB)
private void setupActionBar() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
// Show the Up button in the action bar.
getActionBar().setDisplayHomeAsUpEnabled(true);
}
}
Now take this line out of your code in DisplayMessageActivity
getActionBar().setDisplayHomeAsUpEnabled(true);
and replace it with
setupActionBar();
That way Android checks the API version and if it is below HoneyComb's does not call the getActionBar() method which does not exist on Gingerbread.
I am reading a android book for beginners, and while following on of the chapters I ran into a problem. The chapter is teaching about intents. I right now I have 2 layouts: main.xml, and digital_clock.xml. And in the AndroidManifest I have these lines of code:
<application
android:icon="#drawable/ic_launcher"
android:label="#string/app_name" >
<activity
android:label="#string/app_name"
android:name=".Chapter11Activity" >
<intent-filter >
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".DigitalClockActivity" >
</activity>
</application>
Also I have the two Activity classes that correspond to the layouts:
Chapter11Activity:
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class Chapter11Activity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button a2 = (Button)findViewById(R.id.button1);
a2.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
Intent myIntent = new Intent(v.getContext(), DigitalClockActivity.class);
startActivityForResult(myIntent, 0);
}
});
}
}
DigitalClockActivity:
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class DigitalClockActivity extends Activity {
public void OnCreate(Bundle sIS) {
super.onCreate(sIS);
setContentView(R.layout.digital_clock);
Button a1 = (Button) findViewById(R.id.button01);
a1.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
Intent replyIntent = new Intent();
setResult(RESULT_OK, replyIntent);
finish();
}
});
}
}
When I run the app on my phone and switch to the second activity it shows nothing at all. Am I defining something wrong in the AndroidManifest? The application seems very straight forward, but it is not working. I have check over to make sure I didn't type anything wrong. Is it because I am running a android 2.3.3 phone and using the 1.5 sdk, and something is not backwards compatible? Any answers are appreciated!
~Andrew
Method name in second activity should be onCreate not OnCreate.
To prevent typos like this in the future use #Override on methods that you are overriding:
#Override
public void OnCreate(Bundle sIS) {
// code here
}
Then if you make a typo, the compiler will tell about it.
here
I uploaded my Android project made in Eclipse. The idea is that i have a service, which computes the sum of two random numbers. But when i press the OK Button, i don't see the result in that edit box... why? What i'm doing wrong? Please help
Thanks!
EDIT: The code:
//service class
package service;
import java.util.Random;
import com.android.AplicatieSuma;
import android.widget.EditText;
import android.widget.TextView;
public class ServiciuSuma
{
public ServiciuSuma() { }
public int CalculateSum()
{
Random generator=new Random();
int n=generator.nextInt();
int m=generator.nextInt();
return n+m;
}
}
The Application class:
package com.android;
import android.app.*;
import service.*;
public class ApplicationSum extends Application {
public ServiciuSuma service = new ServiciuSuma();
}
and the main Activity class:
package com.android;
import com.android.R;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Color;
import android.graphics.PorterDuffColorFilter;
import android.graphics.drawable.Drawable;
import android.graphics.PorterDuff;
import android.os.Bundle;
import android.provider.Settings;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.EditText;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
public class Activitate extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
View btn_ok = findViewById(R.id.btn_ok);
btn_ok.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
CalculeazaSuma();
}
});
}
private void CalculeazaSuma()
{
AplicatieSuma appState = ((AplicatieSuma)this.getApplication());
EditText txt_amount = (EditText)findViewById(R.id.txt_amount);
txt_amount.setText(appState.service.CalculateSum());
//BindData();
}
}
So that edit text does not show the sum of the random generated numbers, by the service. What's wrong?
Thanks
EDIT:
the manifest xml file:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.android"
android:versionCode="1"
android:versionName="1.0.1">
<supports-screens
android:largeScreens="true"
android:normalScreens="true"
android:smallScreens="true"
android:anyDensity="true" />
<application android:name="ApplicationSum" android:icon="#drawable/icon" android:label="#string/app_name" android:debuggable="true">
<activity android:label="#string/app_name" android:name=".Activitate">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
<uses-sdk android:minSdkVersion="7" android:targetSdkVersion="7" />
</manifest>
This fix will work:
txt_amount.setText(String.valueOf(appState.service.CalculateSum()));
Without that you pass integer and android thinks it's an id of a resource to display. You should really use DDMS to identify such problems.
Have you specified in manifest that you want ApplicationSum to be used as application class?
<manifest xmlns:android="http://schemas.android.com/apk/res/android">
<application
android:name="com.android.ApplicationSum">
...
</application>
</manifest>
Does this work?
public String CalculateSum()
{
Random generator=new Random();
int n=generator.nextInt();
int m=generator.nextInt();
String sum = Integer.toString(n+m) ;
Log.v("CalculateSum", "N+M = " + sum);
return sum;
}