Develop Reference

Passing data between activities for a voting app

I am new to android programming and have ran into a problem. I am trying to create a voting app where when a user opens up the application and the MainActivity is shown, from here they press a button to go into the second Screen (Screen2) which shows images of people and their names as buttons. When a persons name (in a button on Screen2) is pressed , a text field shows the number of times the button is pressed in an another activity (Screen4) . The problem here is that when i try to show this (Screen4), the app crashes. I am quite new to this so if you didn't understand my issue or need more information please let me know. Any help is appreciated. Thank you.
EDIT : After some help I used Intent to try send the data across but now when when the button in screen2 is pressed the app refreshes and then takes me back to the mainActivity and when this process is tried again the app crashes.
This is the new Screen2 :
package com.example.myapplication1;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
public class Screen2 extends AppCompatActivity {
TextView showValue;
int counter = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_screen2);
showValue = findViewById(R.id.VoteCountAnnie);//VoteCountAnnie is the On click for the Textview in a different activity.
}
public void AnCount(View v) {
//increase the count
counter++;
showValue.setText(Integer.toString(counter));
}
public void ButtonToGoToTheOtherActivity(View v) {
Intent intent = new Intent(this, Screen4.class);
intent.putExtra("valueOfCounter", counter); //the code for sending data to the other activity.
startActivity(intent);
}
}
This is the XML for screen 2 :
<?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">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
tools:context=".Screen2">
<Button
android:id="#+id/AnnieBtn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="32dp"
android:layout_marginLeft="32dp"
android:text="#string/annie_liou"
android:onClick="AnCount"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/imageView5"
/>
This is my Screen4:
package com.example.myapplication1;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class Screen4 extends AppCompatActivity {
private Button Button3;
int counter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_screen4);
Button3 = (Button) findViewById(R.id.Button3);
Button3.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) { openActivity4();
}
}
);
counter = getIntent().getIntExtra("valueOfCounter", 0); // 0 is default value
}
public void openActivity4() {
Intent intent = new Intent(Screen4.this, MainActivity.class);
startActivity(intent);
}
}
Here is the XML for screen4:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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:id="#+id/MainScreen"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".Screen4">
<TextView
android:id="#+id/textView5"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="193dp"
android:layout_marginLeft="193dp"
android:layout_marginEnd="109dp"
android:layout_marginRight="109dp"
android:layout_marginBottom="660dp"
android:text="This is 4th screen"
android:textSize="32sp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.664"
app:layout_constraintStart_toStartOf="parent" />
<Button
android:id="#+id/Button3" // return to main screen
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="532dp"
android:text="Return"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.498"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/textView5" />
<TextView
android:id="#+id/VoteCountAnnie" // textview where i want the increment to show
android:layout_width="121dp"
android:gravity="center"
android:layout_height="52dp"
android:layout_marginStart="116dp"
android:layout_marginLeft="116dp"
android:layout_marginTop="82dp"
android:layout_marginEnd="174dp"
android:layout_marginRight="174dp"
android:text="0"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/textView5" />
</androidx.constraintlayout.widget.ConstraintLayout>
This is my main Activity Screen (not used for the clicking but if there is something wrong in this that could affect the other Screens please let me know) :
package com.example.myapplication1;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
private Button button;
private Button button2;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = (Button) findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
openActivity2();
}
});
button2 = (Button) findViewById(R.id.button2);
button2.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
openActivity3();
}
}
);
}
public void openActivity2() {
Intent intent = new Intent(this, Screen2.class);
startActivity(intent);
}
public void openActivity3() {
Intent intent = new Intent(this, Screen3.class);
startActivity(intent);
}
}
Here is the XML for screen 4:

This works same using intent .
Main Class :
package com.example.cameraone;
import android.content.Intent;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class MainActivity extends AppCompatActivity {
public static String EXTRA_VOTE_KEY = "com.example.cameraone.EXTRA_VOTE_KEY";
private Button counter,show;
private int count = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if(savedInstanceState != null){
count = savedInstanceState.getInt(EXTRA_VOTE_KEY);
}
counter = findViewById(R.id.bt_counter);
show = findViewById(R.id.bt_show);
counter.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
count++;
}
});
show.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
go();
}
});
/* Intent intent = new Intent(this,DisplayCount.class);
//intent.putExtras(intent);
startActivity(intent,bundle);*/
}
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt(EXTRA_VOTE_KEY,count);
}
public void go(){
Intent intent = new Intent(this,DisplayCount.class);
intent.putExtra(EXTRA_VOTE_KEY,count);
startActivity(intent);
}
}
Activity of Main Class :
<?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="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
tools:context=".MainActivity">
<Button
android:id="#+id/bt_counter"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="16dp"
android:text="PressMe"
/>
<Button
android:id="#+id/bt_show"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/bt_counter"
android:text="Done"
/>
</RelativeLayout
Display Class :
package com.example.cameraone;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.widget.Button;
import android.widget.TextView;
import org.w3c.dom.Text;
public class DisplayCount extends AppCompatActivity{
private TextView textView;
private int count;
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.display_count_activity);
textView = findViewById(R.id.tv_vote_count);
Intent intent = getIntent();
count = intent.getIntExtra(MainActivity.EXTRA_VOTE_KEY,0);
textView.setText(Integer.toString(count));
}
}
Activity of display class :
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content" android:layout_height="wrap_content"
android:layout_gravity="center">
<TextView
android:id="#+id/tv_vote_count"
android:layout_width="wrap_content"
android:inputType="number"
android:layout_height="wrap_content"
android:textStyle="bold"
android:maxLength="10"/>
</RelativeLayout>
Manifest :
include following in your manifest file :
<activity android: name =".DisplayCount"></activity>

add following to manifest :
// Main Activity //
- List item
package com.example.cameraone;
import android.content.Intent;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class MainActivity extends AppCompatActivity {
public static String EXTRA_VOTE_KEY = "com.example.cameraone.EXTRA_VOTE_KEY";
private Button counter,show;
private int count = 0;
#Override
protected void onCreate(#Nullable final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
counter = findViewById(R.id.bt_counter);
show = findViewById(R.id.bt_show);
counter.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
count++;
}
});
show.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
go();
}
});
}
public void go(){
DisplayCount.setVoteCount(count);
Intent intent = new Intent(this, DisplayCount.class);
startActivity(intent);
}
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt(EXTRA_VOTE_KEY,count);
}
}
/** Class to display: **/
- List item
package com.example.cameraone;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.widget.Button;
import android.widget.TextView;
import org.w3c.dom.Text;
public class DisplayCount extends AppCompatActivity{
private TextView textView ;
private static int count ;
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.display_count_activity);
textView = findViewById(R.id.tv_vote_count);
textView.setText(Integer.toString(count));`enter code here`
}
public static void setVoteCount(int c){
count = c;
}
}
/***** Activity files *****/
- List item
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content" android:layout_height="wrap_content"
android:layout_gravity="center">
<TextView
android:id="#+id/tv_vote_count"
android:layout_width="wrap_content"
android:inputType="number"
android:layout_height="wrap_content"
android:textStyle="bold"
android:maxLength="10"/>
</RelativeLayout>
/**** Activity That display's ****/
-List item
<?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="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
tools:context=".MainActivity">
<Button
android:id="#+id/bt_counter"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="16dp"
android:text="PressMe"
/>
<Button
android:id="#+id/bt_show"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/bt_counter"
android:text="Done"
/>
</RelativeLayout>

As Mike M. said you are using id of a textview which is in a different activity. In android we cannot access ids of views in a different activity. We can only access ids of view in the same activity in which we are.
So that is for the error you are getting.
For accessing Data from another activity you can pass the data like this:
public class Screen2 extends AppCompatActivity {
int counter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_screen1);
showValue = (TextView) findViewById(R.id.VoteCountAnnie);//VoteCountAnnie is the Id for the Textview in a different activity.
}
public void AnnieCountInc (View view) {
//increase the count
counter++;
showValue.setText(Integer.toString(counter));
}
//make another button with a method like
public void ButtonToGoToTheOtherActivity(View view){
Intent intent =new Intent(this,Screen4.class);
intent.putExtra("valueOfCounter",counter); //the code for sending data to the other activity.
startActivity(intent);
}
Then in your Screen4 activity you can get the value of "counter" in the onCreate method by:
counter = getIntent().getIntExtra("valueOfCounter",0); // 0 is default value
This is one method.
You can also use a static variable to pass on data easily by defining your counter varaible as
public static int counter;
Then you can access it directly and it will show you the value.

Android dynamic listview

I want to make a ListView that gets its elements(strings) from user input. I have a button that directs the user to another activity and while in it, the user enters a name and presses another button to come back to the original activity. The same button gets and adds a string to the ArrayAdapter that the ListView uses and displays it as an element in the ListView. It doesn't seem to work and I know it's a stupid mistake, but I'm fresh to android development and this in particular I haven't done before.
Here's all the code:
the MainActivity
import android.content.Intent;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;
import java.util.ArrayList;
public class MainActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ArrayList<String> simpleArray =new ArrayList<String>();
ListAdapter simpleAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,
simpleArray);
ListView lv = (ListView) findViewById(R.id.lv);
lv.setAdapter(simpleAdapter);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
public void enterActivity(View view) {
Intent toEnterSecond = new Intent(this, SecondActivity.class);
startActivity(toEnterSecond);
}
}
The second acitivity
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import java.util.ArrayList;
public class SecondActivity extends Activity{
private EditText projectName;
ArrayList simpleArray;
ArrayAdapter simpleAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.second);
projectName = (EditText) findViewById(R.id.eTxt);
}
public void getBack(View view) {
String projectCalling = String.valueOf(projectName.getText());
simpleArray.add(projectCalling);
simpleAdapter.notifyDataSetChanged();
Intent comeBack = new Intent(this, MainActivity.class);
startActivity(comeBack);
}
}
And the layouts
<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"
tools:context=".MainActivity">
<Button
android:layout_width="match_parent"
android:layout_height="80dp"
android:id="#+id/simpleButton"
android:text="click me plox"
android:onClick="enterActivity"/>
<ListView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/simpleButton"
android:id="#+id/lv">
</ListView>
</RelativeLayout>
//
<?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">
<TextView
android:layout_width="wrap_content"
android:layout_height="20dp"
android:text="Enter the name of your project:"
android:id="#+id/txt"/>
<EditText
android:layout_width="200dp"
android:layout_height="40dp"
android:layout_below="#+id/txt"
android:id="#+id/eTxt"/>
<Button
android:layout_width="100dp"
android:layout_height="60dp"
android:layout_below="#+id/eTxt"
android:text="click"
android:onClick="getBack"/>
</RelativeLayout>

Explanation:
You can start SecondActivity with startActivityForResult() instead of startActivity as answered here and in onResultActivity method you can call simpleAdapter.notifyDataSetChanged();. Don't call simpleAdapter.notifyDataSetChanged(); in SecondActivity.
To learn how to use startActivityForResult check this.
Also use finish() instead of
Intent comeBack = new Intent(this, MainActivity.class);
startActivity(comeBack);
in SecondActivity to go back to MainActivity.
Solution:
Change MainActivity enterActivity method to this:
...
public void enterActivity(View view) {
Intent toEnterSecond = new Intent(this, SecondActivity.class);
startActivityForResult(toEnterSecond,1);
}
Add this to end of SecondActivity getBack method:
MainActivity.simpleArray.add(projectCalling);
Intent returnIntent = new Intent();
setResult(RESULT_OK,returnIntent);
finish();
Finally add this new method to MainActivity:
protected void onActivityResult(int requestCode, int resultCode, Intent data{
if (requestCode == 1) {
if(resultCode == RESULT_OK){
((ArrayAdapter) simpleAdapter).notifyDataSetChanged();
}
}
}
To be able to access simpleAdapter, you need to define it outside of onCreate:
public class MainActivity extends ActionBarActivity {
private ListAdapter simpleAdapter;
public static ArrayList<String> simpleArray;
#Override
protected void onCreate(Bundle savedInstanceState) {
...
simpleArray =new ArrayList<String>();
simpleAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,
simpleArray);
...
}

Buttons and TextView in Android

I'm trying to learn the ins and outs of Android and I'm finding some real challenges. I am trying to link a Button to a TextView, when you click the Button the value in the TextView changes. I've tried to use some of the sample code I've found online but I get a lot of errors and I'm not sure what to do with them. I'd appreciate any help you could offer.
Thanks so much for your help!
at line 25:
Multiple markers at this line
- main cannot be resolved or is not a field
- R cannot be resolved to a variable
at line 29:
btn1 cannot be resolved or is not a field
at line 32:
Syntax error on token(s), misplaced construct(s)
at line 34:
Multiple markers at this line
- Syntax error on token ")", ; expected
- Syntax error on token "(", ; expected
- void is an invalid type for the variable onClick
at line 36:
txtVw1 cannot be resolved or is not a field
and then here is my code:
package com.demuro1.views;
import android.R;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list_item);
}
#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;
}
Button aBut = (Button) findViewById(R.id.btn1);
public void changeText(){
mButton.setOnClickListener(new View.OnClickListener {
public void onClick(View v) {
final TextView mTextView = (TextView) findViewById(R.id.txtVw1);
mTextView.setText("Some Text");
}
};
}
}
and then the xml from the view
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
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" >
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<LinearLayout
android:layout_width="129dp"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:orientation="vertical" >
<TextView
android:id="#+id/txtVw1"
android:textSize="25sp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="press button 1" />
<Button
android:id="#+id/btn1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:text="Button 1"
android:onClick="activateBtn1"/>
</LinearLayout>
<LinearLayout
android:layout_width="140dp"
android:layout_height="fill_parent"
android:layout_gravity="center_vertical"
android:orientation="vertical" >
<TextView
android:id="#+id/txtVw2"
android:textSize="25sp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="press button 2" />
<Button
android:id="#+id/btn2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button 2"
android:onClick="activateBtn2"/>
/>
</LinearLayout>
</LinearLayout>
</LinearLayout>

Use The following code
package com.demuro1.views;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final Button aBut = (Button)findViewById(R.id.btn1);
Button bBut = (Button)findViewById(R.id.btn2);
final TextView aText = (TextView)findViewById(R.id.txtVw1);
final TextView bText = (TextView)findViewById(R.id.txtVw2);
aBut.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
aText.setText("You Clicked Button 1");
}
});
bBut.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
bText.setText("You Clicked Button 2");
}
});
}
#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;
}
}

You don't need to import android.R
main cannot be resolved or is not a field: make sure that in res/menu folder there is a file called main.xml
btn1 cannot be resolved or is not a field: initialize btn1 in onCreate() after setting the content
Syntax error on token(s), misplaced construct(s): set the button's click listener inside onCreate
txtVw1 cannot be resolved or is not a field: same as in 3
Change your MainActivity.java like this:
package com.demuro1.views;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends Activity {
TextView mTextView;
Button aBut;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mTextView = (TextView) findViewById(R.id.txtVw1);
aBut = (Button) findViewById(R.id.btn1);
aBut.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
mTextView.setText("Some Text");
}
});
// Do similar thing with TextView (R.id.txtVw2) and Button (R.id.btn2) here
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}

Can't get text from editText Android Eclipse

I'm having some issues with my school project. I can't get the text from the textbox. I searched for a solution but nothing found.. I'll be grateful if somebody help me :)
So here is my Java code:
package com.src.vicnote;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.content.Context;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.os.Build;
public class NewNoteActivity extends ActionBarActivity {
Button saveButton;
EditText textData;
Context context;
String text;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_new_note);
saveButton = (Button) this.findViewById(R.id.buttonSave);
saveButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
textData = (EditText) findViewById(R.id.editText);
text = textData.getText().toString();
//text = "this is sparta!";
Log.d("ADebugTag", "string: \"" + text + "\" end of note text");
new SaveClass(text/*, context.getApplicationContext()*/);
}
});
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.new_note, 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_new_note,
container, false);
return rootView;
}
}
}
And my 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.src.vicnote.NewNoteActivity"
tools:ignore="MergeRootFrame" >
<Button
android:id="#+id/buttonSave"
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:text="Save" />
<EditText
android:id="#+id/editText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_alignParentRight="true"
android:layout_below="#+id/buttonSave"
android:ems="10"
android:gravity="top"
android:inputType="textMultiLine" >
<requestFocus />
</EditText>
</RelativeLayout>
Also I want to ask you what will happen if the text is cyrillic? Will be there any problem?

Try initializing textData outside of your OnClickListener:
textData = (EditText) findViewById(R.id.editText);
saveButton = (Button) this.findViewById(R.id.buttonSave);
saveButton.setOnClickListener(new View.OnClickListener() { //...

I was also stuck at finding method to get text from edittext. I got resolved this issue by doing the below,
String selQuantity = (((TextView)findViewById(R.id.etxtQuantity)).getText()).toString();
Try this. It works.

App crashes when changing intent

I'm new to android and the problem feels simple, but I can't place it. I tried to look in logcat, but I can't follow.
Here is the main activity which loads just fine.
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
public class MainActivity extends Activity {
Intent intent;
Button newsButton;
#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;
}
public void sendMessage(View view) {
Intent intent = new Intent(this, NewsActivity.class);
startActivity(intent);
}
}
Here is the corresponding xml:
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:orientation="vertical" >
<Button
android:id="#+id/newsButton"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="104dp"
android:onClick="#layout/news_activity"
android:text="News" />
<Button
android:id="#+id/contactButton"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Contact Us"
android:onClick="#layout/contact_activity" />
<Button
android:id="#+id/findUs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Social Media"
android:onClick="#layout/social_activity" />
<Button
android:id="#+id/fundButton"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Fundraising" />
</LinearLayout>
<TextView
android:id="#+id/titleName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="24dp"
android:text="Send the Scots to Scotland"
android:textSize="24sp" />
</RelativeLayout>
The crash happens on the API 14 device I debug with. After clicking any one of my buttons to change to a new activity that looks like this :(which are all essentially the same as the one below)
package com.gconcode.scotstoscotland;
import android.app.Activity;
import android.os.Bundle;
import android.support.v4.app.NavUtils;
import android.view.Menu;
import android.view.MenuItem;
public class NewsActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.news_activity);
}
#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;
}
#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);
}
}
Sorry I removed the logcat, I wasn't sure if I posted it right. Didn't want too cause the post to be inconvenient thanks for the help!

I think you misunderstand android:onClick. It looks like you are expecting it to load a certain layout file when you click the Button but that is not how it works. The name you give android:onClick should be the name of a function which doesn't return anything and accepts a View as its one and only parameter. It looks like you pulled that from the example in the docs with
public void sendMessage(View view) {
Intent intent = new Intent(this, NewsActivity.class);
startActivity(intent);
}
There are different ways you could do this. Since you already have the android:onClick and you have a method in your Activity, you could change that to look like
android:onClick="sendMessage"
then add a switch statement to that method to open the correct Activity. So something like
public void sendMessage(View view)
{
switch (view.getId()) // get the id of the View clicked
{
case (R.id.newsButton):
Intent intent = new Intent(this, NewsActivity.class);
startActivity(intent);
break;
case (R.id.contactButton):
// assuming ContactActivity.java is an Activity name
Intent intent = new Intent(view.getContext(), ContactActivity.class);
startActivity(intent);
break;
...
}
}
This answer shows a little different way to do the Intent so you cut down on some of the reusable code. If it looks too complicated then don't worry about it until you have a better understanding but just an idea.