Develop Reference

Android Menu not Showing

I'd like to make a menu with a delete option. The actual delete functionality isn't made yet because at the moment I can't see the top bar in my app.
Main layout (activity_main.xml):
<?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: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="billy.cs436.placebadgesapp.MainActivity">
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/newPlace"
android:text="#string/newPlaceButton"
/>
</RelativeLayout>
Menu layout (main.xml):
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:id="#+id/deleteMenu"
android:icon="#drawable/clear"
android:title="#string/deleteMenu"
app:showAsAction="ifRoom"
/>
</menu>
Main activity (MainActivity.java):
package billy.cs436.placebadgesapp;
import android.content.Intent;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;
public class MainActivity extends Activity {
Button newPlace;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
newPlace = (Button) findViewById(R.id.newPlace);
newPlace.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent intent = new Intent(getApplicationContext(), setLocation.class);
startActivity(intent);
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the main; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);//Menu Resource, Menu
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if(id == R.id.deleteMenu) {
// if there are no badges, toast message saying so (needs implementing)
Toast.makeText(this, "There are no badges to delete!", Toast.LENGTH_SHORT).show();
//else clear all badges
} else {
Toast.makeText(this, "Badges cleared!", Toast.LENGTH_SHORT).show();
}
return super.onOptionsItemSelected(item);
}
}
Can anyone tell my why the New Place button is the only thing that shows up when this is run?
EDIT:
#T.S has the correct answer. Thank you.

Change your class to extend AppCompatActivity instead of Activity.

Adding more Buttons when a Button in clicked

Please look at the following algorithm and tell me if I can achieve it:
create a main_activity
inside the main_activity, create a simple Button
the Button is labeled as "Add Button"
once the users clicks the Button, an additional Button is created and placed in the Activity.
In other words:
once the user clicks on the add Button, it should create another Button and
place it under the "Add Button" Button.
I apologize in advance as this may be confusing, so please feel free to comment and ask for clarification.
I originally thought about creating a separate method, in which I would create a ButtonView, but I am not sure how I can physically create a Button.
Would I need to apply code to .xml file also?
I am really confused.
Here is my code:
MainActivity.java
package inc.fimp;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button addArm = (Button) findViewById(R.id.btnAddArm);
addArm.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
addButton();
}
});
}
public boolean onCreateOptionsMenu(Menu menu){
MenuInflater menuInflater = getMenuInflater();
menuInflater.inflate(R.menu.menu_main, menu);
return true;
}
public boolean onOptionsItemSelected(MenuItem item){
int res_id = item.getItemId();
if(res_id==R.id.action_contact)
{
Toast.makeText(getApplicationContext(), "You selected Contacted us option", Toast.LENGTH_SHORT).show();
}
if(res_id==R.id.action_settings){
Toast.makeText(getApplicationContext(), "You selected Settings Option", Toast.LENGTH_SHORT).show();
}
return true;
}
public void addButton(){
// create an aditional button
}
}
xml file code
<?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: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="inc.fimp.MainActivity">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/add_arm"
android:textStyle="italic"
android:id="#+id/btnAddArm"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:background="#drawable/addarm"
android:singleLine="false" />
</RelativeLayout>

Start by adding an ID to the parent layout
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/buttonContainer"
Then, get that with findViewById. ViewGroup simply used because that is all you need to get the addView method.
public class MainActivity extends AppCompatActivity {
private ViewGroup rootView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
rootView = (ViewGroup) findViewById(R.id.buttonContainer);
Then, in the addButton,
Button button = new Button(MainActivity.this); // Need to provide the context, the Activity
// button.setText("Added!"); // for example
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
params.addRule(RelativeLayout.ALIGN_PARENT_LEFT, RelativeLayout.TRUE);
params.addRule(RelativeLayout.BELOW, R.id.btnAddArm);
// params.addRule ... (there's a bunch you can add)
rootView.addView(button, params);
Since you have a RelativeLayout, you can also programmatically put LayoutParams to do layout above/below, etc. other views.

How to make two diffrent Activities to use the same layout Android

Below code works fine, but it opens a new layout and shows the toast message. but i wanted it to show toast & popup menus on the current layout. I'm working on popup menu project, i want to show popup menu on same layout. Thanks in Advance.
MainMactivity.java
package com.example.twoact;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class MainActivity extends Activity {
Button b1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
b1 = (Button) findViewById(R.id.button1);
b1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent openpopactivity = new Intent(MainActivity.this,
MainActivity2.class);
startActivity(openpopactivity);
}
});
}
}
MainActivity2.java
package com.example.twoact;
import android.widget.Toast;
import android.os.Bundle;
import android.os.Handler;
public class MainActivity2 extends MainActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
new Handler().postDelayed(new Runnable() {
public void run() {
Toast.makeText(getApplicationContext(), "ya am in",
Toast.LENGTH_SHORT).show();
}
}, 1000);
}
}
activity_main.xml
<RelativeLayout 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.twoact.MainActivity"
tools:ignore="MergeRootFrame" >
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="142dp"
android:text="Button" />
</RelativeLayout>

You can use Popup menu and Popup window. in this you can use your custom layout so you can get your view as window in same activity.
Popup window will be good option because it is since API LEVEL 1
please refer this docs and example 1,example 2
And Popup Menu is since API LEVEL 11. so you have to manage for lower version
docs for Popup Menu and example
popup window

Unfortunately (project name) has stopped working on button click

An area which will present a predefined question
A button which will cause the answer to the question to be shown while leaving the question on the screen
An area which will present the answer
A button which will cause a transition to a screen that is formatted the same as this one, with the next question shown on it
A button which will cause the app to end (a transition to (3))
Only trying to get the transition from screen 1 to screen 2 to work with a different question/answer pair in its place with a button click. If there is anyway to do this other than switching the screens and activities which is the error, please let me know.
package com.example.androidassignment2;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.content.Intent;
public class AndroidAssignment2 extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_android_assignment2_1);
Button next = (Button) findViewById(R.id.QButton);
next.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Intent intent = new Intent();
setResult(RESULT_OK, intent);
finish();
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.android_assignment2_1, menu);
return true;
}
}
layout file
<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/Questions"
android:layout_weight="1"
android:layout_width="wrap_content"
android:layout_height="0dip"
android:text="#string/Q2" />
<Button android:id="#+id/QButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/button_question" />
<Button android:id="#+id/AButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/button_send" />
<TextView android:id="#+id/Answers"
android:layout_weight="1"
android:layout_width="wrap_content"
android:layout_height="0dip"
android:hint="#string/A2" />
<Button android:id="#+id/QuitButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/button_quit" />
</LinearLayout>
activity 1 file (incase needed)
package com.example.androidassignment2;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.content.Intent;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button next = (Button) findViewById(R.id.QButton);
next.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Intent myIntent = new Intent(view.getContext(), AndroidAssignment2_1.class);
startActivityForResult(myIntent, 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;
}
}

Intent myIntent = new Intent(view.getContext(), AndroidAssignment2_1.class);
startActivityForResult(myIntent, 0);
You are starting a new activity, the most likely cause is that this is has not been declared in the Manifest.
In your AndroidManifest.xml`, you will need to add something like this:
<activity
android:name="your.package.name.AndroidAssignment2_1" />
This will reside inside of the <application> tag.

You are using startActivityForResult() but you don't override the onActivityForResult() method in your first Activity. You could change that to just use startActivity() and remove setResult() from your second Activity.
Button next = (Button) findViewById(R.id.QButton);
next.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Intent myIntent = new Intent(view.getContext(), AndroidAssignment2_1.class);
startActivity(myIntent);
}
});
If this isn't your problem then please post logcat (always when you have a crash) and make sure the Activity is decalred.
As far as your other inquiry
If there is anyway to do this other than switching the screens and activities which is the error, please let me know.
If you are simply changing the text then you can stay in the same Activity and change the text of your TextViews. You could store questions and answers in something like Arrays or in a DB if you wish and keep a counter to where you are and change the text with each click.
Another option, which may go along with the first if you want, is to use a ViewPager

Android application restarts when opened by clicking the application icon

I am new to the Android development world and I've built a simple "Hello World" app. First, activity requests a text. When the "Go" button is clicked, the app launches the second activity displaying the input text.
If I click the HOME button and then click the application icon, the app launches the first activity again but if I press-hold the home button and click the icon from the "Recent apps" bar, it resumes the app where I left.
How do I avoid this?
I need my app to resume even if the launcher icon is clicked.
MainActivity.java,
package com.example.myfirstandroidapp;
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.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.txtName);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE, message);
startActivity(intent);
}
}
DisplayActivity.java,
package com.example.myfirstandroidapp;
import android.annotation.TargetApi;
import android.app.Activity;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.support.v4.app.NavUtils;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
public class DisplayMessageActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// 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 as the activity layout
setContentView(textView);
// Show the Up button in the action bar.
setupActionBar();
}
/**
* Set up the {#link android.app.ActionBar}, if the API is available.
*/
#TargetApi(Build.VERSION_CODES.HONEYCOMB)
private void setupActionBar() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
getActionBar().setDisplayHomeAsUpEnabled(true);
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.display_message, menu);
return true;
}
#Override
public void onDestroy(){
super.onDestroy();
}
#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);
}
}
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" >
<EditText
android:id="#+id/txtName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="70dp"
android:ems="10" >
<requestFocus />
</EditText>
<Button
android:id="#+id/btnGo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="#+id/txtName"
android:layout_alignParentRight="true"
android:onClick="sendMessage"
android:text="Go!" />
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/txtName"
android:layout_alignParentTop="true"
android:layout_marginTop="18dp"
android:text="Please input your name:"
android:textAppearance="?android:attr/textAppearanceMedium" />
</RelativeLayout>
activity_display_message.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=".DisplayMessageActivity" >
<TextView
android:id="#+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/hello_world" />
</RelativeLayout>
AndroidManifest.xml,
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.myfirstandroidapp"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="9"
android:targetSdkVersion="10" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.myfirstandroidapp.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.myfirstandroidapp.DisplayMessageActivity"
android:label="#string/title_activity_display_message"
android:parentActivityName="com.example.myfirstandroidapp.MainActivity" >
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.myfirstandroidapp.MainActivity" />
</activity>
</application>
</manifest>

Problem:
I'm not qualified to say this a bug, but there is a behaviour with release builds when starting the application from the launcher. It seems that instead of resuming the previous Activity, it adds a new Activity on top. There is a related bug report on this topic here.
Solution:
I'm working around this this by closing the Launcher Activity if it's not the root of the task, as a result the previous Activity in that task will be resumed.
if (!isTaskRoot()) {
finish();
return;
}

Issue for me was whenever app in installed by an apk with the click on 'Open' option it used to relaunch every time when we minimize it.
resolved it by
SplashActivity.java:
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
if (!isTaskRoot
&& intent.hasCategory(Intent.CATEGORY_LAUNCHER)
&& intent.action != null
&& intent.action.equals(Intent.ACTION_MAIN)) {
finish()
return
}
}