Develop Reference

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);
}
}
}
}

probleme with android.text.Editable android.widget.EditText.getText() on a null object reference [duplicate]

This question already has answers here:
What is a NullPointerException, and how do I fix it?
(12 answers)
Closed 3 years ago.
I'm a new in programming,
I want to search in a TextView. I have this code for searching in my TextView. I am using a custom toolbar
package com.example.mohsin.customlistview;
import android.graphics.Typeface;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.text.ParcelableSpan;
import android.text.Spannable;
import android.text.SpannableString;
import android.text.style.StyleSpan;
import android.view.View;
import android.widget.EditText;
import android.widget.ScrollView;
import android.widget.TextView;
import android.support.v7.widget.Toolbar;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
public class loi52055 extends AppCompatActivity {
TextView textloi2;
ScrollView textViewWrapper;
EditText texttoolbar;
String target;
int selected;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_loi52055);
Toolbar toolbar = findViewById(R.id.toolbark);
setSupportActionBar(toolbar);
textloi2 = findViewById(R.id.textloi52055);
textViewWrapper = findViewById(R.id.textViewWrapper);
// textloi.setMovementMethod(new ScrollingMovementMethod());
String data = "";
StringBuffer dahirbuffer = new StringBuffer();
InputStream is = this.getResources().openRawResource(R.raw.loi5205);
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
if(is != null){
try {
while((data=reader.readLine())!= null){
dahirbuffer.append(data + "\n");
}
textloi2.setText(dahirbuffer);
is.close();
}catch(Exception e){
e.printStackTrace();
}
}
textloi2.setMovementMethod(new CustomMovementMethod());
textloi2.setTextIsSelectable(true);
texttoolbar = findViewById(R.id.edittexttoolbar1);
target = texttoolbar.getText().toString();
selected = changeTextView(textloi2, target, selected);
findViewById(R.id.next).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
selected++;
}
});
findViewById(R.id.previous).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
selected--;
}
});
}
private int changeTextView(TextView tv, String target, int selected) {
if (selected < 0) {
selected = 0;
}
String bString = tv.getText().toString();
int startSpan = 0, endSpan = 0;
Spannable spanRange = new SpannableString(bString);
int currentIndex = 0;
while (true) {
startSpan = bString.indexOf(target, endSpan);
endSpan = startSpan + target.length();
boolean isLast = bString.indexOf(target, endSpan) < 0;
if (startSpan < 0)
break;
ParcelableSpan span;
if (currentIndex == selected || isLast && selected > currentIndex) {
// selected span
span = new StyleSpan(Typeface.BOLD_ITALIC);
if (isLast && selected > currentIndex) {
// normalize if selected out of bounds
selected = currentIndex;
}
} else {
// deselected span
span = new StyleSpan(Typeface.BOLD);
}
currentIndex++;
spanRange.setSpan(
span,
startSpan,
endSpan,
Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
}
tv.setText(spanRange);
if (currentIndex == 0) {
// text not found
return -1;
} else {
return selected;
}
}
}
But when I run it I have this :
java.lang.NullPointerException: Attempt to invoke virtual method'android.text.Editable android.widget.EditText.getText()' on a null object reference
layout :
<?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"
android:orientation="vertical"
tools:context=".loi52055"
>
<ScrollView
android:id="#+id/scrollview1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
>
<TextView
android:id="#+id/textloi52055"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="4dp"
android:focusable="true"
android:longClickable="true"
android:scrollbars="vertical"
android:textColor="#000000"
android:textIsSelectable="true" />
</ScrollView>
</RelativeLayout>

Your problem is not with the TextView but with the EditText
texttoolbar = findViewById(R.id.edittexttoolbar1);
You have to add an EditText with id edittexttoolbar1 in your activity_loi52055 layout or include the layout inside the one that contains edittexttoolbar1

Modify ListView based on user entry

I am trying to modify the contents of a ListView as the user types into an EditText. It is working mostly but the strange thing is that it does not restore the list when characters are deleted. when going through debugger mode I see two things happening and I don't know why.
jobs which containes the original list is modified, even though I am not modifying it in my code as far as I know.
In the getNewArray method,
if(newArray.size() == 0) {
return jobs;
}
is never executed even when newArray.size() is 0 (checked in debugger mode)
here is the activity:
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.Arrays;
public class MainActivity extends AppCompatActivity {
String[] stringArray = {"557K", "559B", "601A", "357K", "459B", "501A", "657K", "759B", "801A"};
private ArrayList<String> jobs;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
jobs = new ArrayList<String>(Arrays.asList(stringArray));
setContentView(R.layout.activity_main);
ListView listView = (ListView)findViewById(R.id.listView);
final ArrayAdapter adapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, jobs);
listView.setAdapter(adapter);
final EditText editText = (EditText) findViewById(R.id.editText);
// set listener for list view. clicked item populates the EditText
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
String text = ((TextView) view).getText().toString();
String[] subStrings = text.split(" :", 2);
editText.setText(subStrings[0]);
}
});
// set text watcher to modify content in list as user types into EditText
TextWatcher textWatcher = new TextWatcher() {
#Override
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
#Override
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
#Override
public void afterTextChanged(Editable editable) {
// get modified array
ArrayList<String> newList = StringMatcher.getNewArray(jobs, editable.toString());
// refresh viewList
adapter.clear();
adapter.addAll(newList);
adapter.notifyDataSetChanged();
}
};
editText.addTextChangedListener(textWatcher);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, 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();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
Layout:
<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"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin" tools:context=".MainActivity">
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/editText" />
<ListView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/listView" />
StringMatcher class:
import java.util.ArrayList;
public class StringMatcher {
private StringMatcher(){}
/**
* Taken from András Belicza
* http://stackoverflow.com/questions/86780/is-the-contains-method-in-java-lang-string-case-sensitive
* On 29/10/2015
* #param src
* #param what
* #return
*/
private static boolean containsIgnoreCase(String src, String what) {
final int length = what.length();
if (length == 0)
return true; // Empty string is contained
final char firstLo = Character.toLowerCase(what.charAt(0));
final char firstUp = Character.toUpperCase(what.charAt(0));
for (int i = src.length() - length; i >= 0; i--) {
// Quick check before calling the more expensive regionMatches() method:
final char ch = src.charAt(i);
if (ch != firstLo && ch != firstUp)
continue;
if (src.regionMatches(true, i, what, 0, length))
return true;
}
return false;
}
public static ArrayList<String> getNewArray(ArrayList<String> jobs, String newString) {
ArrayList<String> newArray = new ArrayList<String>();
for(String job: jobs){
if(containsIgnoreCase(job,newString))
newArray.add(job);
}
if(newArray.size() == 0) {
return jobs;
}
else {
return newArray;
}
}
}

How to pass value from a method to another method

import android.support.v4.app.Fragment;
import android.app.Activity;
import android.app.Dialog;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.view.inputmethod.InputMethodManager;
import android.widget.*;
import android.widget.NumberPicker.OnValueChangeListener;
public class MainActivity extends Activity implements OnValueChangeListener {
EditText push_ups, sit_ups;
NumberPicker np;
Button calculate;
final Context context = this;
CheckBox checkbox;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
calculate = (Button)findViewById(R.id.calculate);
push_ups = (EditText)findViewById(R.id.pushups);
sit_ups = (EditText)findViewById(R.id.situps);
np = (NumberPicker)findViewById(R.id.np1);
checkbox = (CheckBox)findViewById(R.id.checkbox);
String[] values = {"some array"};
np.setMaxValue(values.length-1);
np.setMinValue(0);
np.setDisplayedValues(values);
np.setWrapSelectorWheel(false);
//calculateButton runs when I click the "calculate" Button
calculateButton();
LinearLayout layout = (LinearLayout)findViewById(R.id.linearLayout1);
layout.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
hideKeyboard();
return false;
}
});
}
#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;
}
#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_main, container,
false);
return rootView;
}
}
#Override
public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
}
private void hideKeyboard() {
InputMethodManager imm = (InputMethodManager)context.getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(push_ups.getWindowToken(), 0);
}
public int calculatePushups() {
int pushupScore = 0;
int ageGroup = Integer.parseInt(null, np.getValue());
int pushupReps = Integer.parseInt(push_ups.getText().toString());
final int [][] pushupTable = {"some 2D array"};
if (pushupReps<= 60) {
pushupScore = pushupTable[pushupReps][ageGroup];
} else {
pushupScore = 60;
}
return pushupScore;
}
public int calculateSitups() {
final int [][] situpTable = {"some 2D array"};
return 0;
}
private void normalRun() {
}
private void specialRun() {
}
private void calculateRun() {
if (checkbox.isChecked()) {
specialRun();
}
else {
normalRun();
}
}
private void calculateScore() {
calculatePushups();
calculateSitups();
calculateRun();
}
public void calculateButton() {
final TextView pus = (TextView)findViewById(R.id.pushup_score);
calculate.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// custom dialog
final Dialog dialog = new Dialog(context);
dialog.setContentView(R.layout.dialog_custom);
dialog.setTitle("Score");
I am trying to set the TextView to display the pushupScore here but it seems I am trying to pass a result from another method to this. I have no idea how to get it around still new with android,
//pus.setText(pushupScore);
pus.setText(String.valueOf(calculatePushups()));
Button dialogButton = (Button) dialog.findViewById(R.id.dialog_ok);
// if button is clicked, close the custom dialog
dialogButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
dialog.dismiss();
}
});
dialog.show();
}
});
}
}
Here's my dialog XML code:
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:lineSpacingExtra="5dp"
android:text="Push-ups: "
android:textAppearance="?android:attr/textAppearanceMedium" />
<TextView
android:id="#+id/pushup_score"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="4.97"
android:textAppearance="?android:attr/textAppearanceMedium" />
</LinearLayout>
<TextView
android:id="#+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:lineSpacingExtra="5dp"
android:text="Sit-ups: "
android:textAppearance="?android:attr/textAppearanceMedium" />
<TextView
android:id="#+id/textView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:lineSpacingExtra="5dp"
android:text="2.4km Run: "
android:textAppearance="?android:attr/textAppearanceMedium" />
<TextView
android:id="#+id/textView4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:lineSpacingExtra="5dp"
android:text="Award: "
android:textAppearance="?android:attr/textAppearanceLarge" />
<Button
android:id="#+id/dialog_ok"
style="#style/AppTheme"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:lineSpacingExtra="5dp"
android:text="Ok" />
</LinearLayout>

you are returning the pushupScore in calculatePushups so just write:
pus.setText(String.valueOf(calculatePushups()));
And btw this is not a android mechanism, this is simple java return usage:
http://docs.oracle.com/javase/tutorial/java/javaOO/returnvalue.html

You left out quite a bit of your code so I'm not sure where your problem is, but if you could follow these steps and let me know if you're getting any errors etc? Anyway, here is what you need to have:
Make sure your Activity implements OnClickListener:
public class MainActivity extends Activity implements OnClickListener, OnValueChangeListener {
//...
}
Within the activity's overridden onCreate() method, register the activity as the handler:
calculate = (Button)v.findViewById(R.id.dialog_ok);
calculate.setOnClickListener(this);
Within MainActivity, have the handler like so:
public void onClick(View v){
switch(v.getId(){
case R.id.dialog_ok:
push_ups.setText("" + calculatePushups());
break;
}
// ...
}
Perhaps you should change your EditText into a TextView, the EditText isn't necessary and might be causing problems?
Is this what you were after?

Add and Remove Views in Android Dynamically?

How do I add and remove views such as TextViews from Android app like on the original stock Android contacts screen where you press a small icon on the right side of a field and it adds or deletes a field which consists of a TextView and an editTextView (from what I can see).
Any examples on how to achieve this?

ViewParents in general can't remove views, but ViewGroups can. You need to cast your parent to a ViewGroup (if it is a ViewGroup) to accomplish what you want.
For example:
View namebar = View.findViewById(R.id.namebar);
((ViewGroup) namebar.getParent()).removeView(namebar);
Note that all Layouts are ViewGroups.

I need the exact same feature described in this question. Here is my solution and source code: https://github.com/laoyang/android-dynamic-views. And you can see the video demo in action here: http://www.youtube.com/watch?v=4HeqyG6FDhQ
Layout
Basically you'll two xml layout files:
A horizontal LinearLayout row view with a TextEdit, a Spinner and an ImageButton for deletion.
A vertical LinearLayout container view with just a Add new button.
Control
In the Java code, you'll add and remove row views into the container dynamically, using inflate, addView, removeView, etc. There are some visibility control for better UX in the stock Android app. You need add a TextWatcher for the EditText view in each row: when the text is empty you need to hide the Add new button and the delete button. In my code, I wrote a void inflateEditRow(String) helper function for all the logic.
Other tricks
Set android:animateLayoutChanges="true" in xml to enable animation
Use custom transparent background with pressed selector to make the buttons visually the same as the ones in the stock Android app.
Source code
The Java code of the main activity ( This explains all the logic, but quite a few properties are set in xml layout files, please refer to the Github source for complete solution):
public class MainActivity extends Activity {
// Parent view for all rows and the add button.
private LinearLayout mContainerView;
// The "Add new" button
private Button mAddButton;
// There always should be only one empty row, other empty rows will
// be removed.
private View mExclusiveEmptyView;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.row_container);
mContainerView = (LinearLayout) findViewById(R.id.parentView);
mAddButton = (Button) findViewById(R.id.btnAddNewItem);
// Add some examples
inflateEditRow("Xiaochao");
inflateEditRow("Yang");
}
// onClick handler for the "Add new" button;
public void onAddNewClicked(View v) {
// Inflate a new row and hide the button self.
inflateEditRow(null);
v.setVisibility(View.GONE);
}
// onClick handler for the "X" button of each row
public void onDeleteClicked(View v) {
// remove the row by calling the getParent on button
mContainerView.removeView((View) v.getParent());
}
// Helper for inflating a row
private void inflateEditRow(String name) {
LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
final View rowView = inflater.inflate(R.layout.row, null);
final ImageButton deleteButton = (ImageButton) rowView
.findViewById(R.id.buttonDelete);
final EditText editText = (EditText) rowView
.findViewById(R.id.editText);
if (name != null && !name.isEmpty()) {
editText.setText(name);
} else {
mExclusiveEmptyView = rowView;
deleteButton.setVisibility(View.INVISIBLE);
}
// A TextWatcher to control the visibility of the "Add new" button and
// handle the exclusive empty view.
editText.addTextChangedListener(new TextWatcher() {
#Override
public void afterTextChanged(Editable s) {
// Some visibility logic control here:
if (s.toString().isEmpty()) {
mAddButton.setVisibility(View.GONE);
deleteButton.setVisibility(View.INVISIBLE);
if (mExclusiveEmptyView != null
&& mExclusiveEmptyView != rowView) {
mContainerView.removeView(mExclusiveEmptyView);
}
mExclusiveEmptyView = rowView;
} else {
if (mExclusiveEmptyView == rowView) {
mExclusiveEmptyView = null;
}
mAddButton.setVisibility(View.VISIBLE);
deleteButton.setVisibility(View.VISIBLE);
}
}
#Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
}
#Override
public void onTextChanged(CharSequence s, int start, int before,
int count) {
}
});
// Inflate at the end of all rows but before the "Add new" button
mContainerView.addView(rowView, mContainerView.getChildCount() - 1);
}

This is my general way:
View namebar = view.findViewById(R.id.namebar);
ViewGroup parent = (ViewGroup) namebar.getParent();
if (parent != null) {
parent.removeView(namebar);
}

Hi You can try this way by adding relative layout and than add textview in that.
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
(LayoutParams.WRAP_CONTENT), (LayoutParams.WRAP_CONTENT));
RelativeLayout relative = new RelativeLayout(getApplicationContext());
relative.setLayoutParams(lp);
TextView tv = new TextView(getApplicationContext());
tv.setLayoutParams(lp);
EditText edittv = new EditText(getApplicationContext());
edittv.setLayoutParams(lp);
relative.addView(tv);
relative.addView(edittv);

Just use myView.setVisibility(View.GONE); to remove it completely.
But if you want to reserve the occupied space inside its parent use myView.setVisibility(View.INVISIBLE);

Kotlin Extension Solution
Add removeSelf to directly call on a view. If attached to a parent, it will be removed. This makes your code more declarative, and thus readable.
myView.removeSelf()
fun View?.removeSelf() {
this ?: return
val parent = parent as? ViewGroup ?: return
parent.removeView(this)
}
Here are 3 options for how to programmatically add a view to a ViewGroup.
// Built-in
myViewGroup.addView(myView)
// Reverse addition
myView.addTo(myViewGroup)
fun View?.addTo(parent: ViewGroup?) {
this ?: return
parent ?: return
parent.addView(this)
}
// Null-safe extension
fun ViewGroup?.addView(view: View?) {
this ?: return
view ?: return
addView(view)
}

ViewGroup class provides API for child views management in run-time, allowing to add/remove views as well.
Some other links on the subject:
Android, add new view without XML Layout
Android Runtime Layout Tutorial
http://developer.android.com/reference/android/view/View.html
http://developer.android.com/reference/android/widget/LinearLayout.html

For Adding the Button
LinearLayout dynamicview = (LinearLayout)findViewById(R.id.buttonlayout);
LinearLayout.LayoutParams lprams = new LinearLayout.LayoutParams( LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
Button btn = new Button(this);
btn.setId(count);
final int id_ = btn.getId();
btn.setText("Capture Image" + id_);
btn.setTextColor(Color.WHITE);
btn.setBackgroundColor(Color.rgb(70, 80, 90));
dynamicview.addView(btn, lprams);
btn = ((Button) findViewById(id_));
btn.setOnClickListener(this);
For removing the button
ViewGroup layout = (ViewGroup) findViewById(R.id.buttonlayout);
View command = layout.findViewById(count);
layout.removeView(command);

Hi First write the Activity class. The following class have a Name of category and small add button. When you press on add (+) button it adds the new row which contains an EditText and an ImageButton which performs the delete of the row.
package com.blmsr.manager;
import android.app.Activity;
import android.app.ListActivity;
import android.content.Intent;
import android.graphics.Color;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.LinearLayout;
import android.widget.ScrollView;
import android.widget.TableLayout;
import android.widget.TableRow;
import android.widget.TextView;
import com.blmsr.manager.R;
import com.blmsr.manager.dao.CategoryService;
import com.blmsr.manager.models.CategoryModel;
import com.blmsr.manager.service.DatabaseService;
public class CategoryEditorActivity extends Activity {
private final String CLASSNAME = "CategoryEditorActivity";
LinearLayout itsLinearLayout;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_category_editor);
itsLinearLayout = (LinearLayout)findViewById(R.id.linearLayout2);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_category_editor, 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.
switch (item.getItemId()) {
case R.id.action_delete:
deleteCategory();
return true;
case R.id.action_save:
saveCategory();
return true;
case R.id.action_settings:
return true;
default:
return super.onOptionsItemSelected(item);
}
}
/**
* Adds a new row which contains the EditText and a delete button.
* #param theView
*/
public void addField(View theView)
{
itsLinearLayout.addView(tableLayout(), itsLinearLayout.getChildCount()-1);
}
// Using a TableLayout as it provides you with a neat ordering structure
private TableLayout tableLayout() {
TableLayout tableLayout = new TableLayout(this);
tableLayout.addView(createRowView());
return tableLayout;
}
private TableRow createRowView() {
TableRow tableRow = new TableRow(this);
tableRow.setPadding(0, 10, 0, 0);
EditText editText = new EditText(this);
editText.setWidth(600);
editText.requestFocus();
tableRow.addView(editText);
ImageButton btnGreen = new ImageButton(this);
btnGreen.setImageResource(R.drawable.ic_delete);
btnGreen.setBackgroundColor(Color.TRANSPARENT);
btnGreen.setOnClickListener(anImageButtonListener);
tableRow.addView(btnGreen);
return tableRow;
}
/**
* Delete the row when clicked on the remove button.
*/
private View.OnClickListener anImageButtonListener = new View.OnClickListener() {
#Override
public void onClick(View v) {
TableRow anTableRow = (TableRow)v.getParent();
TableLayout anTable = (TableLayout) anTableRow.getParent();
itsLinearLayout.removeView(anTable);
}
};
/**
* Save the values to db.
*/
private void saveCategory()
{
CategoryService aCategoryService = DatabaseService.getInstance(this).getCategoryService();
aCategoryService.save(getModel());
Log.d(CLASSNAME, "successfully saved model");
Intent anIntent = new Intent(this, CategoriesListActivity.class);
startActivity(anIntent);
}
/**
* performs the delete.
*/
private void deleteCategory()
{
}
/**
* Returns the model object. It gets the values from the EditText views and sets to the model.
* #return
*/
private CategoryModel getModel()
{
CategoryModel aCategoryModel = new CategoryModel();
try
{
EditText anCategoryNameEditText = (EditText) findViewById(R.id.categoryNameEditText);
aCategoryModel.setCategoryName(anCategoryNameEditText.getText().toString());
for(int i= 0; i< itsLinearLayout.getChildCount(); i++)
{
View aTableLayOutView = itsLinearLayout.getChildAt(i);
if(aTableLayOutView instanceof TableLayout)
{
for(int j= 0; j< ((TableLayout) aTableLayOutView).getChildCount() ; j++ );
{
TableRow anTableRow = (TableRow) ((TableLayout) aTableLayOutView).getChildAt(i);
EditText anEditText = (EditText) anTableRow.getChildAt(0);
if(StringUtils.isNullOrEmpty(anEditText.getText().toString()))
{
// show a validation message.
//return aCategoryModel;
}
setValuesToModel(aCategoryModel, i + 1, anEditText.getText().toString());
}
}
}
}
catch (Exception anException)
{
Log.d(CLASSNAME, "Exception occured"+anException);
}
return aCategoryModel;
}
/**
* Sets the value to model.
* #param theModel
* #param theFieldIndexNumber
* #param theFieldValue
*/
private void setValuesToModel(CategoryModel theModel, int theFieldIndexNumber, String theFieldValue)
{
switch (theFieldIndexNumber)
{
case 1 :
theModel.setField1(theFieldValue);
break;
case 2 :
theModel.setField2(theFieldValue);
break;
case 3 :
theModel.setField3(theFieldValue);
break;
case 4 :
theModel.setField4(theFieldValue);
break;
case 5 :
theModel.setField5(theFieldValue);
break;
case 6 :
theModel.setField6(theFieldValue);
break;
case 7 :
theModel.setField7(theFieldValue);
break;
case 8 :
theModel.setField8(theFieldValue);
break;
case 9 :
theModel.setField9(theFieldValue);
break;
case 10 :
theModel.setField10(theFieldValue);
break;
case 11 :
theModel.setField11(theFieldValue);
break;
case 12 :
theModel.setField12(theFieldValue);
break;
case 13 :
theModel.setField13(theFieldValue);
break;
case 14 :
theModel.setField14(theFieldValue);
break;
case 15 :
theModel.setField15(theFieldValue);
break;
}
}
}
2. Write the Layout xml as given below.
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:background="#006699"
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.blmsr.manager.CategoryEditorActivity">
<LinearLayout
android:id="#+id/addCategiryNameItem"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal">
<TextView
android:id="#+id/categoryNameTextView"
android:layout_width="200dp"
android:layout_height="wrap_content"
android:text="#string/lbl_category_name"
android:textStyle="bold"
/>
<TextView
android:id="#+id/categoryIconName"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:text="#string/lbl_category_icon_name"
android:textStyle="bold"
/>
</LinearLayout>
<LinearLayout
android:id="#+id/linearLayout1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<EditText
android:id="#+id/categoryNameEditText"
android:layout_width="200dp"
android:layout_height="wrap_content"
android:hint="#string/lbl_category_name"
android:inputType="textAutoComplete" />
<ScrollView
android:id="#+id/scrollView1"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<LinearLayout
android:id="#+id/linearLayout2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<LinearLayout
android:id="#+id/linearLayout3"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
</LinearLayout>
<ImageButton
android:id="#+id/addField"
android:layout_width="50dp"
android:layout_height="50dp"
android:layout_below="#+id/addCategoryLayout"
android:src="#drawable/ic_input_add"
android:onClick="addField"
/>
</LinearLayout>
</ScrollView>
</LinearLayout>
Once you finished your view will as shown below

//MainActivity :
package com.edittext.demo;
import android.app.Activity;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.Toast;
public class MainActivity extends Activity {
private EditText edtText;
private LinearLayout LinearMain;
private Button btnAdd, btnClear;
private int no;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
edtText = (EditText)findViewById(R.id.edtMain);
btnAdd = (Button)findViewById(R.id.btnAdd);
btnClear = (Button)findViewById(R.id.btnClear);
LinearMain = (LinearLayout)findViewById(R.id.LinearMain);
btnAdd.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
if (!TextUtils.isEmpty(edtText.getText().toString().trim())) {
no = Integer.parseInt(edtText.getText().toString());
CreateEdittext();
}else {
Toast.makeText(MainActivity.this, "Please entere value", Toast.LENGTH_SHORT).show();
}
}
});
btnClear.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
LinearMain.removeAllViews();
edtText.setText("");
}
});
/*edtText.addTextChangedListener(new TextWatcher() {
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
}
#Override
public void beforeTextChanged(CharSequence s, int start, int count,int after) {
}
#Override
public void afterTextChanged(Editable s) {
}
});*/
}
protected void CreateEdittext() {
final EditText[] text = new EditText[no];
final Button[] add = new Button[no];
final LinearLayout[] LinearChild = new LinearLayout[no];
LinearMain.removeAllViews();
for (int i = 0; i < no; i++){
View view = getLayoutInflater().inflate(R.layout.edit_text, LinearMain,false);
text[i] = (EditText)view.findViewById(R.id.edtText);
text[i].setId(i);
text[i].setTag(""+i);
add[i] = (Button)view.findViewById(R.id.btnAdd);
add[i].setId(i);
add[i].setTag(""+i);
LinearChild[i] = (LinearLayout)view.findViewById(R.id.child_linear);
LinearChild[i].setId(i);
LinearChild[i].setTag(""+i);
LinearMain.addView(view);
add[i].setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
//Toast.makeText(MainActivity.this, "add text "+v.getTag(), Toast.LENGTH_SHORT).show();
int a = Integer.parseInt(text[v.getId()].getText().toString());
LinearChild[v.getId()].removeAllViews();
for (int k = 0; k < a; k++){
EditText text = (EditText) new EditText(MainActivity.this);
text.setId(k);
text.setTag(""+k);
LinearChild[v.getId()].addView(text);
}
}
});
}
}
#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;
}
}
// Now add xml main
<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"
tools:context=".MainActivity" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:orientation="horizontal" >
<EditText
android:id="#+id/edtMain"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:layout_weight="1"
android:ems="10"
android:hint="Enter value" >
<requestFocus />
</EditText>
<Button
android:id="#+id/btnAdd"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="10dp"
android:text="Add" />
<Button
android:id="#+id/btnClear"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="5dp"
android:layout_marginRight="5dp"
android:text="Clear" />
</LinearLayout>
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="10dp" >
<LinearLayout
android:id="#+id/LinearMain"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
</LinearLayout>
</ScrollView>
// now add view xml file..
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:orientation="horizontal" >
<EditText
android:id="#+id/edtText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:ems="10" />
<Button
android:id="#+id/btnAdd"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="10dp"
android:text="Add" />
</LinearLayout>
<LinearLayout
android:id="#+id/child_linear"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="30dp"
android:layout_marginRight="10dp"
android:layout_marginTop="5dp"
android:orientation="vertical" >
</LinearLayout>