intent not working when swiching from one activity to another

intent not working when swiching from one activity to another - android

I have made a simple android program with two activities,in that 1st activity contains an edittext and a button,and second activity contain a textview.Now when the button in 1st activity pressed the text from Edittext should go to 2nd activity's textView.I have tried code as below,but it's not working:
MainActivity.java
package com.example.myweb;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
public class MainActivity extends Activity {
public final static String EXTRA_MESSAGE = "com.example.myweb";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button b =(Button)findViewById(R.id.button1);
b.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
EditText ed = (EditText)findViewById(R.id.edit_msg);
Intent i = new Intent(getApplicationContext(),Act2.class);
String s= ed.getText().toString();
i.putExtra("EXTRA_MESSAGE", s);
startActivity(i);
}
});
}
}
Act2.java
package com.example.myweb;
import org.w3c.dom.Text;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class Act2 extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.act2);
Button b1=(Button)findViewById(R.id.button1);
b1.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
TextView tv = (TextView)findViewById(R.id.tv1);
Intent i =getIntent();
String msg = i.getStringExtra(MainActivity.EXTRA_MESSAGE);
tv.setText(msg);
setContentView(tv);
}
});
}
}
please help me.thank you

Just try this:
In MainActivity.java:
declare Button b and EditText ed as a class field (i.e. keep it outside onCreate())
class MainActivity.java
{
Button b;
EditText ed;
...
onCreate() {
...
b =(Button)findViewById(R.id.button1);
ed = (EditText)findViewById(R.id.edit_msg);
b.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent i = new Intent(MainActivity.this,Act2.class);
String s= ed.getText().toString();
i.putExtra("EXTRA_MESSAGE", s);
startActivity(i);
}
});
...
In Act2.java:
...
Intent i = getIntent();
String msg = i.getStringExtra("EXTRA_MESSAGE");
TextView tv = (TextView)findViewById(R.id.tv1);
tv.setText(msg);
Button b1=(Button)findViewById(R.id.button1);
b1.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
}
});
...

You are using
Intent intent = getIntent();
String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
So, in MainActivity
i.putExtra(EXTRA_MESSAGE, s);
startActivity(i);
(OR)
String message = intent.getStringExtra("EXTRA_MESSAGE");
also,
i.putExtra("EXTRA_MESSAGE", s);

Change
String msg = i.getStringExtra(MainActivity.EXTRA_MESSAGE);
to
String msg = i.getStringExtra("EXTRA_MESSAGE");
MainActivity.EXTRA_MESSAGE would mean a static variable of MainActivity.java class. Hope you get the difference. You need the variable EXTRA_MESSAGE which you had put in intent i
Edit: For your crash, we need a logcat o/p and activity, manifest code. But possible reasons:
Activity Act2.java is not declared in manifest file.
You said you have only a textview in second activity. But you are trying to get button1 from act2.xml. So you are getting Force close.
Change Act2.java 's onCreate() as
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.act2);
TextView tv = (TextView)findViewById(R.id.tv1);
Intent i =getIntent();
String msg = i.getStringExtra("EXTRA_MESSAGE");
tv.setText(msg);
}
You don't need to call setContentView(tv); as it is already there in act2.xml and you are using setContentView(R.layout.act2);
Hope your problem gets solved.

Use this code
**MainActivity.java**
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button button = (Button)findViewById(R.id.button1);
final EditText editText = (EditText)findViewById(R.id.editText1);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent = new Intent(getApplicationContext(), SecondActivity.class);
intent.putExtra("EXTRA_MESSAGE", editText.getText().toString());
startActivity(intent);
}
});
}
}
**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/editText1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="74dp"
android:layout_marginTop="26dp"
android:ems="10" >
<requestFocus />
</EditText>
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="#+id/editText1"
android:layout_marginLeft="69dp"
android:layout_marginTop="47dp"
android:text="Button" />
</RelativeLayout>
**SecondActivity.java**
public class SecondActivity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// TODO Auto-generated method stub
setContentView(R.layout.second);
Intent intent = getIntent();
final String message = intent.getStringExtra("EXTRA_MESSAGE");
Button button = (Button)findViewById(R.id.button1);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
TextView textView = new TextView(SecondActivity.this);
textView.setText(message);
setContentView(textView);
}
});
}
}
**second.xml**
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button" />
</LinearLayout>
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.tester"
android:versionCode="1"
android:versionName="1.0" >
<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.tester.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".SecondActivity"></activity>
</application>
</manifest>

Try
Intent i = new Intent(MainActivity.this,Act2.class);

You are using
Intent intent = getIntent();
String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
So, in MainActivity
i.putExtra(EXTRA_MESSAGE, s);
startActivity(i);

please review and change your code its works
package com.example.activityact;
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;
import android.widget.EditText;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button b =(Button)findViewById(R.id.button1);
b.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
EditText ed = (EditText)findViewById(R.id.editText1);
Intent i = new Intent(getApplicationContext(),Act2.class);
String s= ed.getText().toString();
i.putExtra("EXTRA_MESSAGE", s);
startActivity(i);
}
});
}
}
Act2.java
package com.example.activityact;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;
public class Act2 extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.act2);
// TODO Auto-generated method stub
TextView tv = (TextView) findViewById(R.id.textView1);
Intent i =getIntent();
// String msg = i.getStringExtra(EXTRA_MESSAGE);
//String receiver = getIntent().getStringExtra(EXTRA_MESSAGE);
String message = i.getStringExtra("EXTRA_MESSAGE");
tv.setText(message);
}
}

Value of the EXTRA_MESSAGE variable in MainActivity.java is different then the key value that you are putting message in to intent.
MainActivity.java:
public final static String EXTRA_MESSAGE = "com.example.myweb";
i.put("EXTRA_MESSAGE",s);
Act2.java: (you are accessing by extra_message variable which is not correct)
Intent i = getIntent();
String text = i.getStringExtra(MainActivity.EXTRA_MESSAGE); //WHICH IS DIFFER FROM THE KEY VALUE
So key value should be the same at the time of setting and getting the value. here while setting the value key is "EXTRA_MESSAGE" and while getting "com.example.myweb" so you will get null pointer exception.
SOLUTION:
just change the line in Act2.java
Intent i = getIntent();
String text = i.getStringExtra("EXTRA_MESSAGE");
Also check your menifest file for the activities declaration.
Hope it may help you.

Did you remember to correctly define your second activity in the manifest XML?
Check out this great guide for anything else you might have missed: http://developer.android.com/training/basics/firstapp/starting-activity.html

Related

change the text in another activity

I have a button in Activity A, which changes the text in it when clicked. There is an Activity B in which I need the TextView to become visible and its text to be the same as the text in the button on the Activity A. Please help.
Activity A
package com.example.myapplication;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import androidx.annotation.Nullable;
public class SmActivity extends Activity {
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sm);
Button btn_apple = (Button) findViewById(R.id.button_apple);
Button btn_cherry = (Button) findViewById(R.id.button_cherry);
Button btn_orange = (Button) findViewById(R.id.button_orange);
Button btn_waterLemon = (Button) findViewById(R.id.button_waterlemon);
View.OnClickListener appleListener = new View.OnClickListener() {
boolean action = false;
#Override
public void onClick(View v) {
if (!action) {
action = true;
btn_apple.setText("1");
}
else {
int i = Integer.parseInt(btn_apple.getText().toString());
btn_apple.setText(String.valueOf(i + 1));
i = i;
}
}
};
View.OnClickListener cherryListener = new View.OnClickListener() {
boolean action = false;
#Override
public void onClick(View v) {
if (!action) {
action = true;
btn_cherry.setText("1");
}
else {
int j = Integer.parseInt(btn_cherry.getText().toString());
btn_cherry.setText(String.valueOf(j + 1));
j = j;
}
}
};
View.OnClickListener orangeListener = new View.OnClickListener() {
boolean action = false;
#Override
public void onClick(View v) {
if (!action) {
action = true;
btn_orange.setText("1");
}
else {
int k = Integer.parseInt(btn_orange.getText().toString());
btn_orange.setText(String.valueOf(k + 1));
k = k;
}
}
};
View.OnClickListener waterListener = new View.OnClickListener() {
boolean action = false;
#Override
public void onClick(View v) {
if (!action) {
action = true;
btn_waterLemon.setText("1");
} else {
int q = Integer.parseInt(btn_waterLemon.getText().toString());
btn_waterLemon.setText(String.valueOf(q + 1));
q = q;
}
}
};
btn_apple.setOnClickListener(appleListener);
btn_cherry.setOnClickListener(cherryListener);
btn_orange.setOnClickListener(orangeListener);
btn_waterLemon.setOnClickListener(waterListener);
}
public void OnClickBsk(View view){
Intent intent = new Intent(SmActivity.this, BasketActivity.class);
startActivity(intent);
}
public void OnClickProfile(View view){
Intent intent = new Intent(SmActivity.this, ProfileActivity.class);
startActivity(intent);
}
}

Do this In Activity A when you click button to go to next Activity B
btn.setOnClickListener(v -> {
Intent i = new Intent(AActivity.this,BActivity.class);
// This below line sends Key- btnText and Value- Apple
i.putExtra("btnText","Apple");
startActivity(i);
});
In BActivity do this to button
// Here you receives data from activity a with the help of Key- btnText
btn.setText(getIntent().getStringExtra("btnText"));
This is a simple way to do this.

I Have Solved the answer for you,
Minor Explanations is in the comments in code.
Use this code as a concept and apply changes to yours based on your requirement.
XML of Activity A:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".ActivityA">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Text Before Button Click"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:id="#+id/text_to_change"
android:textSize="20sp"
/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#id/text_to_change"
android:id="#+id/change_text_btn"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:layout_margin="20dp"
android:text="Change Text and Start Activity B"
/>
</RelativeLayout>
Java of Activity A
package com.example.text_to_speech;
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;
import org.w3c.dom.Text;
public class ActivityA extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_activity);
TextView textView;
Button button;
textView=findViewById(R.id.text_to_change);
button=findViewById(R.id.change_text_btn);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String newtext="New Text From Activity A";
textView.setText(newtext);
Intent intent=new Intent(ActivityA.this,ActivityB.class);
intent.putExtra("Change", newtext);//this string will be
//accessed by activityB
startActivity(intent);
}
});
}
}
XML of Activity B:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".ActivityB">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Waiting for New Text"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:id="#+id/new_textview"
android:textSize="20sp"
android:visibility="gone"
/>
</RelativeLayout>
Java of Activity B:
package com.example.text_to_speech;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;
public class ActivityB extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_b);
TextView textView;
textView=findViewById(R.id.new_textview);
// Below if block is looking for an intent, if it gets it and
// there is content in the extras with key "Change",
// it will make the textview in xml visible and update its string
// based on value set by Activity A
if(savedInstanceState == null) {
Bundle extras = getIntent().getExtras();
if (extras == null) {
Toast.makeText(ActivityB.this, "Can't Get the Intent", Toast.LENGTH_LONG).show();
} else {
String get_String = extras.getString("Change");
textView.setVisibility(View.VISIBLE);// be default i have set the visibility to gone in xml
//here it will get visible and then filled with the string sent by the intent in activity A
textView.setText(get_String);
}
}
}
}

Display User Input from one activity to another in a textView

I tried to display User Input from my main activity to my second activity, but when I typed in and click the send button on the main activity the whole app just crashes. Please help!
crash solved! Thanks a lot!
However, I can't get the message to display on the second activity.
MainActivity.java
package com.example.dell_inspiron.sendmessage;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import static android.R.id.message;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final String message = getResources().getString(R.string.UserInput);
final Button send = (Button) findViewById(R.id.send);
send.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v) {
Intent sendMessage = new Intent(MainActivity.this, DisplayMessageActivity.class);
sendMessage.putExtra("UserInput", message);
startActivity(sendMessage);
}
});
}
}
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:id="#+id/activity_main"
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="com.example.dell_inspiron.sendmessage.MainActivity">
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:inputType="textPersonName"
android:text="#string/edit"
android:ems="10"
android:layout_below="#+id/textView"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_marginTop="15dp"
android:id="#+id/UserInput" />
<Button
android:text="#string/send"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/UserInput"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_marginTop="14dp"
android:id="#+id/send"
android:onClick="sendMessage" />
<TextView
android:text="#string/text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/textView"
android:textSize="18sp"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
</RelativeLayout>
DisplayMessageActivity.java
package com.example.dell_inspiron.sendmessage;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class DisplayMessageActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_display_message);
Intent Extra = getIntent();
String textView = Extra.getStringExtra("UserInput");
TextView UserInput = (TextView) findViewById(R.id.UserOutput);
UserInput.setText(textView);
final Button button = (Button) findViewById(R.id.button2);
button.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v) {
launchActivity();
}
});
}
private void launchActivity() {
Intent intent = new Intent(this, MainActivity.class);
startActivity(intent);
}
}
activity_display_message.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:id="#+id/activity_display_message"
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="com.example.dell_inspiron.sendmessage.DisplayMessageActivity">
<Button
android:text="#string/Button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="51dp"
android:id="#+id/button2" />
<TextView
android:text="#string/UserOutput"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="91dp"
android:id="#+id/UserOutput" />
<TextView
android:text="#string/enter"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:id="#+id/enter"
android:textSize="18sp"
android:textColor="#android:color/holo_purple" />
</RelativeLayout>

You are passing int, but receive it in String, so your app crashed.
MainActivity
int message = R.string.UserInput;
Intent sendMessage = new Intent(MainActivity.this, DisplayMessageActivity.class);
sendMessage.putExtra("UserInput", message);
DisplayMessageActivity
Bundle Extra = getIntent().getExtras();
String textView = Extra.getString("UserInput");
You should also add
intent.putExtra("UserInput", message);
into launchActivity method.
Solution 1
Change String textView = Extra.getString("UserInput"); to int textView= Extra.getIntExtra("UserInput", 0);
Solution 2
To send the message to your second Activity, you need to use intent inside your MainActivity button click. Modify your code as below.
package com.example.dell_inspiron.sendmessage;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import static android.R.id.message;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String message = getResources().getString(R.string.UserInput);
final Button send = (Button) findViewById(R.id.send);
send.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v) {
Intent sendMessage = new Intent(MainActivity.this,DisplayMessageActivity.class);
sendMessage.putExtra("UserInput", message);
startActivity(sendMessage);
}
});
}
}
Solution 3
This line look wrong to me
final String message = getResources().getString(R.string.UserInput);
If you want to get the editText string, this is the way to go
EditText input = (EditText)findViewById(R.id.UserInput); // declare your editText
final String message = input.getText().toString(); // get your input type

You mentioned that you are getting the user input from the MainActivity but i don't see anything like that in your code but you can do the below to pass some value from one activity to another...
Change your second activity like this
Bundle Extra = getIntent().getExtras();
String textView = Extra.getString("UserInput");
to
Intent Extra = getIntent();
String textView = Extra.getStringExtra("UserInput");
and change your MainActivity like this
int message = R.string.UserInput;
to
String message= getResources().getString(R.string.UserInput);
and
final Button send = (Button) findViewById(R.id.send);
send.setOnClickListener(new View.OnClickListener(){
public void onClick(View v) {
launchActivity();
}
});
to
Button send = (Button) findViewById(R.id.send);
send.setOnClickListener(new View.OnClickListener(){
public void onClick(View v) {
startActivity(sendMessage);
}
});

There is issue with your second Activity.You are passing int value in Intents but trying to get String value.
Change it as below:
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;
public class DisplayMessageActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_display_message);
Bundle Extra = getIntent().getExtras();
int textView = Extra.getInt("UserInput");
TextView UserInput = (TextView) findViewById(R.id.UserInput2);
UserInput.setText(textView);
final Button button = (Button) findViewById(R.id.button2);
button.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v) {
launchActivity();
}
});
}
private void launchActivity() {
Intent intent = new Intent(this, MainActivity.class);
startActivity(intent);
}
}

How to make visible and invisible an image by clicking a button in android studio?

i have two activities in android studio.act1 with a button and act2 with an imageView. i want to click the button in act1 and make the image in act2 visible. and when i click button for second time, this time make the image invisible and do it again and again and again. how can i do that?

you must create this class;
public class PublicSharedPreferences {
public static void setDefaults(String key, String value, Context context) {
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
SharedPreferences.Editor editor = prefs.edit();
editor.putString(key, value);
editor.commit();
}
public static String getDefaults(String key, Context context) {
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
return preferences.getString(key, null);
}
}
and then learn sharedpreferences enter link description here
Activity1;
public class Activity1 extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.layout1);
Button btn1 = (Button) findViewById(R.id.btn1);
btn1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String visibilityStr = PublicSharedPreferences.getDefaults("keyVisibility", getApplicationContext());
if (visibilityStr != null) {
if (visibilityStr.equals("0")) {
Toast.makeText(Activity1.this, "it visibled", Toast.LENGTH_SHORT).show();
visibilityStr = "1";
} else {
visibilityStr = "0";
Toast.makeText(Activity1.this, "it invisibled", Toast.LENGTH_SHORT).show();
}
} else {
visibilityStr = "1";
Toast.makeText(Activity1.this, "it visibled", Toast.LENGTH_SHORT).show();
}
PublicSharedPreferences.setDefaults("keyVisibility", visibilityStr, getApplicationContext());
Intent intent = new Intent(Activity1.this, Activity2.class);
Activity1.this.startActivity(intent);
}
});
}
}
Activity2;
public class Activity2 extends AppCompatActivity {
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.layout2);
ImageView imgView = (ImageView) findViewById(R.id.imgView1);
String visibilityStr = PublicSharedPreferences.getDefaults("keyVisibility", getApplicationContext());
if (visibilityStr.equals("0"))
imgView.setVisibility(View.INVISIBLE);
else
imgView.setVisibility(View.VISIBLE);
}
}
Layout1;
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.c.a.myapplication.Activity1">
<Button
android:id="#+id/btn1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button1"/>
</LinearLayout>
Layout2;
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ImageView
android:id="#+id/imgView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#android:drawable/ic_menu_camera"
android:visibility="invisible"/>
</LinearLayout>
Its work.

Try this code....
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;
import android.widget.ImageView;
public class Sample extends Activity {
ImageView img;
Button btn;
boolean clicked = true;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.sample);
btn = (Button) findViewById(R.id.t1);
btn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
clicked = true;
Intent intent = new Intent(Sample.this, Dample.class);
intent.putExtra("value", true);
startActivity(intent);
}
});
}
}
//Dample.class In second activity
import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.widget.Button;
public class Dample extends Activity {
ImageView img;//use image view
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.pimple);
img= (ImageView) findViewById(R.id.t1);
Boolean yourBool = getIntent().getExtras().getBoolean("value");
if (yourBool == true) {
img.setVisibility(View.VISIBLE);///use visibility code for imageview as mentioned above
}
}
}

button settext to next class

I have two classes; the first.class and second.class. On my first.class there is a button and on my second.class there is no button. I need it so when the button from the first.class is clicked there will be a text that will appear on the second.class with an option to save it.
first.class
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
}
});

public class first{
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
second.setText(text);
}
});
}
public class second{
private static String textFromFirst;
public static void setText(String text){
second.textFromFirst = text;
}
}

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" >
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="57dp"
android:layout_marginTop="23dp"
android:text="Click" />
</RelativeLayout>
MainActivity.java
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MainActivity extends Activity {
Button btn;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn = (Button) findViewById(R.id.button1);
btn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent in = new Intent(getBaseContext(), Second.class);
startActivity(in);
}
});
}
}
second.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text=""
android:textAppearance="?android:attr/textAppearanceLarge" />
</LinearLayout>
Second.java
import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
public class Second extends Activity {
TextView tv;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.second);
tv = (TextView)findViewById(R.id.textView1);
}
#Override
public void onResume()
{
super.onResume();
tv.setText("Hello");
}
}
manifest
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.f"
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.f.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=".Second" />
</application>
</manifest>

do this:
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent p = new Intent(first.this,
second.class);
startActivity(p);
}
});
and then in second class load a xml file containing textview
package ......;
import java.io.File;
import java.io.IOException;
import dolphin.devlopers.com.R;
import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
public class gmail1 extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.second); //the file which contains textview and ui
TextView tv = (TextView)findViewById(R.id.textView1);
}
Manifest file:
<Activity
android:name="first">
</Activity>
<Activity
android:name="second">
</Activity>
second.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="hi"
/>
</RelativeLayout >

Your question is a bit unclear.
When you say first.class and second.class, do you mean they both extends Activity?
Meaning, they are two different "Screens" in your app, and clicking the button on the first activity would launch the second and change its text? if so, You can use intents to pass info between activities. Something like this:
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(first.this, second.class);
// NOW COMES THE IMPORTANT PART, Put the text you want to be passed
intent.putExtra("text_identifier", "The text to show");
startActivity(intent);
}
});
and in Second.java:
private TextView tv;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.second);
tv = (TextView) findViewById(R.id.textView);
// Retreive the text you sent eralier
String theText = getIntent().getStringExtra("text_identifier");
tv.setText(theText);
// Do any extra onCreate things
}
If it's not what you're after, let me know and I'll see what I can think off, but please try to explain a bit better
Good luck!

Android app hangs when referencing the back button on Secondary screen

I have a small app that when button presses navigates when moving from main screen to next screen this works fine, but when I added a button on the next page (to go back) it breaks.
Fun.java
package com.forcetechnology.OptusApp;
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 Fun extends Activity {
OnClickListener backListener;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fun);
Button backButtonf = (Button)findViewById(com.forcetechnology.OptusApp.R.id.backtoMainf);
backListener = new OnClickListener()
{
public void onClick(View v)
{
Intent i = new Intent();
i.setClassName("com.forcetechnology.OptusApp", "com.forcetechnology.OptusApp.OptusAppMain");
startActivity(i);
}
};
backButtonf.setOnClickListener(backListener);
}
}
Fun.Xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<ImageButton
android:id="#+id/backtoMainf"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/val5" />
</LinearLayout>
Main.xml
<ImageButton
android:id="#+id/funbutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:background="#drawable/val5"
android:src="#drawable/val5" />
<ImageButton
android:id="#+id/executionbutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="#+id/funbutton"
android:layout_alignParentRight="true"
android:background="#drawable/val2"
android:src="#drawable/val2" />
<ImageButton
android:id="#+id/performancebutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/executionbutton"
android:layout_toLeftOf="#+id/funbutton"
android:background="#drawable/val3"
android:src="#drawable/val4" />
<ImageButton
android:id="#+id/innovationbutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="#+id/executionbutton"
android:layout_alignParentLeft="true"
android:background="#drawable/val3"
android:src="#drawable/val3" />
<ImageButton
android:id="#+id/peoplebutton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="#+id/innovationbutton"
android:layout_toLeftOf="#+id/executionbutton"
android:background="#drawable/val1"
android:src="#drawable/val1" />
</RelativeLayout>
OPtusAppMain.java
package com.forcetechnology.OptusApp;
import android.R;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ImageButton;
import android.widget.TextView;
import android.widget.Toast;
public class OptusAppMain extends Activity
{
OnClickListener funListener,executionListener,innovationListener,peopleListener,performanceListener;;
TextView testView;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(com.forcetechnology.OptusApp.R.layout.main);
ImageButton funButton = (ImageButton)findViewById(com.forcetechnology.OptusApp.R.id.funbutton);
ImageButton executionButton = (ImageButton)findViewById(com.forcetechnology.OptusApp.R.id.executionbutton);
ImageButton innovationButton = (ImageButton)findViewById(com.forcetechnology.OptusApp.R.id.innovationbutton);
ImageButton peopleButton = (ImageButton)findViewById(com.forcetechnology.OptusApp.R.id.peoplebutton);
ImageButton performanceButton = (ImageButton)findViewById(com.forcetechnology.OptusApp.R.id.performancebutton);
funListener = new OnClickListener()
{
public void onClick(View v)
{
Intent i = new Intent();
i.setClassName("com.forcetechnology.OptusApp", "com.forcetechnology.OptusApp.Fun");
startActivity(i);
}
};
executionListener = new OnClickListener()
{
public void onClick(View v)
{
Intent i = new Intent();
i.setClassName("com.forcetechnology.OptusApp", "com.forcetechnology.OptusApp.Execution");
startActivity(i);
}
};
innovationListener = new OnClickListener()
{
public void onClick(View v)
{
Intent i = new Intent();
i.setClassName("com.forcetechnology.OptusApp", "com.forcetechnology.OptusApp.Innovation");
startActivity(i);
}
};
peopleListener = new OnClickListener()
{
public void onClick(View v)
{
Intent i = new Intent();
i.setClassName("com.forcetechnology.OptusApp", "com.forcetechnology.OptusApp.People");
startActivity(i);
}
};
performanceListener = new OnClickListener()
{
public void onClick(View v)
{
Intent i = new Intent();
i.setClassName("com.forcetechnology.OptusApp", "com.forcetechnology.OptusApp.Performance");
startActivity(i);
}
};
funButton.setOnClickListener(funListener);
executionButton.setOnClickListener(executionListener);
innovationButton.setOnClickListener(innovationListener);
peopleButton.setOnClickListener(peopleListener);
performanceButton.setOnClickListener(performanceListener);
}
}
Edit: I have traced the error to this line Button backButtonf = (Button)findViewById(com.forcetechnology.OptusApp.R.id.backtoMainf); in fun.java.

In the onClick() of backListener, just call finish() to go back to the previous activity.

Lets take an example: You have two activities "A" & "B", You start your "B" activity from "A" that means your "A" activity is in stack so there is no need to start it again, just finish your "B" activity with "finish()" method.
public class A extends Activity{
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
public void onAbuttonClick()
{
startActivity(new Intent(A.this,B.class));
}
}
}
public class B extends Activity
{
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.second);
}
public onBbuttonclick(View v)
{
finish();
}
}
}

Develop Reference

The Android operating system is a mobile operating system that was developed by Google (GOOGL?) to be primarily used for touchscreen devices, cell phones, and tablets.

intent not working when swiching from one activity to another - android

You are using Intent intent = getIntent(); String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE); So, in MainActivity i.putExtra(EXTRA_MESSAGE, s); startActivity(i); (OR) String message = intent.getStringExtra("EXTRA_MESSAGE"); also, i.putExtra("EXTRA_MESSAGE", s);

Try Intent i = new Intent(MainActivity.this,Act2.class);

You are using Intent intent = getIntent(); String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE); So, in MainActivity i.putExtra(EXTRA_MESSAGE, s); startActivity(i);

Did you remember to correctly define your second activity in the manifest XML? Check out this great guide for anything else you might have missed: http://developer.android.com/training/basics/firstapp/starting-activity.html

Related

change the text in another activity

Display User Input from one activity to another in a textView

How to make visible and invisible an image by clicking a button in android studio?

button settext to next class

Android app hangs when referencing the back button on Secondary screen

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