Develop Reference

I want to add the same cardView of my xml underneath the first one when i clic on the add Button and that can be maked endlessly

Hello i'm stcuk by a little problem,
I want to add a new CardView with same set of the first CardView underneath the first Cardview only when i click on my button and this action can be repetable endlessly.
Because i'm beginner in android and i have litterally no idea how to make that.
If anyone can Copy Past this code and help me i will be very happy.
I know the spinner is void but its for after i just want to duplicate this.
my activity :
package com.example.lif.test;
public class testActivity extends AppCompatActivity {
Spinner idSpinnerLance;
EditText idEdtTempsLance;
TextView idTextViewPuissance, textViewTitre;
Button idButtonAdd;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_test);
idSpinnerLance = findViewById(R.id.idSpinnerLance);
idEdtTempsLance = findViewById(R.id.idEdtTempsLance);
textViewTitre = findViewById(R.id.textViewTitre);
idTextViewPuissance = findViewById(R.id.idTextViewPuissance);
idButtonAdd = findViewById(R.id.idButtonAdd);
idButtonAdd.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
}
});
}
}
and my xml code :
<?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">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".test.testActivity">
<androidx.cardview.widget.CardView
android:layout_width="match_parent"
android:layout_height="match_parent"
app:cardCornerRadius="10dp"
android:layout_margin="2dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Ajouter une lance :"
android:textColor="?android:textColorPrimary"
android:textSize="15dp"
android:textStyle="bold" />
<Spinner
android:id="#+id/idSpinnerLance"
android:layout_width="150dp"
android:layout_height="47dp" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Temps :"
android:textColor="?android:textColorPrimary"
android:textSize="15dp"
android:textStyle="bold" />
<EditText
android:id="#+id/idEdtTempsLance"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="phone" />
</LinearLayout>
</androidx.cardview.widget.CardView>
<Button
android:id="#+id/idButtonAdd"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="add" />
</LinearLayout>
</ScrollView>
thank you

If those CardView will contain different data you can use a RecyclerView and on button click you can add an item in the list and notify the adapter this will add a new item(here item is your CardView created in a different XML file) on screen.
This could be helpful
and this too

Make a normal layout look like a PreferenceScreen

The PreferenceScreen isn't good enough for me, since I've to add items to a Spinner. Those items need to come from a data list.
I've got a custom ArrayAdapter that returns the name of the item, and when I click it. It returns the data that is contained within the item.
I want to use that same ArrayAdapter in a ListPreference (that's the spinner in the PreferenceScreen) but the ListPreference doesn't allow me to use a Adapter.
So, I want to recreate the look of the PreferenceScreen (with the PreferenceCategory's) without the use of the actual PreferenceScreen (and PreferenceCategory's)
Is this possible with a library? I haven't found one.
Thanks,
Tim

I tried to collect my first method - I hope I didn't forget to include some parts (aapart color definitions or statelist drawables, which is a trivial task to make your own)
Customizing the standard Preferences
/res/xml/prefs.xml
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
>
<!-- ... -->
<PreferenceCategory android:title="#string/pref_vibrate_cat">
<CheckBoxPreference
android:persistent="true"
android:key="vibrate"
android:title="#string/pref_vibrate_title"
android:summary="#string/pref_vibrate_summ"
android:defaultValue="true"
android:layout="#layout/prefs"
/>
</PreferenceCategory>
<!-- ... -->
<!-- Just to show how to use a custom preference (you must have the corresponding java Class in your project) -->
<PreferenceCategory android:title="#string/pref_tts_cat">
<com.dergolem.abc.CLS_Prefs_Multi
android:persistent="true"
android:key="tts"
android:title="#string/pref_tts_title"
android:summary="#string/nothing"
android:dialogTitle="#string/pref_tts_dlg"
android:dialogIcon="#android:drawable/sym_action_chat"
android:entries="#array/prefs_tts_titles"
android:entryValues="#array/prefs_tts_values"
android:defaultValue="#array/prefs_tts_defaults"
android:layout="#layout/prefs"
android:widgetLayout="#layout/arr_dn"
/>
</PreferenceCategory>
<!-- ... -->
</PreferenceScreen>
/res/layout/prefs.xml
<?xml version="1.0" encoding="utf-8"?>
<!-- Layout for a visually child-like Preference in a PreferenceActivity. -->
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:baselineAligned="false"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:minHeight="?android:attr/listPreferredItemHeight"
android:gravity="center_vertical"
android:paddingStart="16dp"
android:paddingEnd="?android:attr/scrollbarSize"
>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:minWidth="16dp"
android:gravity="center"
android:orientation="horizontal"
>
<ImageView
android:id="#+android:id/icon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
/>
</LinearLayout>
<RelativeLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
android:layout_marginTop="8dp"
android:layout_marginBottom="8dp"
android:layout_weight="1"
>
<TextView
android:id="#+android:id/displayTitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:singleLine="true"
android:textAppearance="?android:attr/textAppearanceMedium"
android:textStyle="bold"
android:ellipsize="marquee"
android:fadingEdge="horizontal"
/>
<TextView
android:id="#+android:id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:singleLine="true"
android:textAppearance="?android:attr/textAppearanceMedium"
android:textStyle="bold"
android:ellipsize="marquee"
android:fadingEdge="horizontal"
/>
<TextView
android:id="#+android:id/summary"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#android:id/title"
android:layout_alignStart="#android:id/title"
android:textAppearance="?android:attr/textAppearanceSmall"
android:textColor="?android:attr/textColorSecondary"
android:shadowColor="#color/white"
android:shadowDx="1"
android:shadowDy="1"
android:shadowRadius="1"
android:maxLines="4"
/>
</RelativeLayout>
<!-- Preference should place its actual preference widget here. -->
<LinearLayout
android:id="#+android:id/widget_frame"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:minWidth="48dp"
android:gravity="center"
android:orientation="vertical"
/>
</LinearLayout>
/src/ACT_Prefs
package com.dergolem.abc;
/* ---------------------------------- Imports ------------------------------- */
import android.annotation.SuppressLint;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
import android.content.res.Configuration;
import android.graphics.PixelFormat;
import android.os.Bundle;
import android.preference.PreferenceActivity;
import android.preference.PreferenceManager;
import android.widget.ListView;
public final class ACT_Prefs // NO_UCD (use default)
extends PreferenceActivity
implements OnSharedPreferenceChangeListener
{
/* ------------------------------ Objects ------------------------------- */
private Context ctx = null;
/* ----------------------------- Overrides ------------------------------ */
// Reload the Activity on rotation.
#Override
public final void onConfigurationChanged(final Configuration cfg)
{
super.onConfigurationChanged(cfg);
reStart();
}
/*
Load the Preference Activity if the API LEvel is less than 11 or else load
the PreferenceFragment.
Needed workaround, since unfortunately Google didn't include the
PreferenceFragment in the support library
*/
#Override
public final void onCreate(final Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
ctx = getApplicationContext();
if (Build.VERSION.SDK_INT < 11)
{
createPreference_Activity();
}
else
{
createPreference_Fragment();
}
}
#Override
protected void onPause()
{
// Unregister OnSharedPreferenceChangeListener
PreferenceManager.getDefaultSharedPreferences(ctx).
unregisterOnSharedPreferenceChangeListener(this);
// Call the base method
super.onPause();
}
#Override
protected void onResume()
{
// Register OnSharedPreferenceChangeListener
PreferenceManager.getDefaultSharedPreferences(ctx).
registerOnSharedPreferenceChangeListener(this);
// Fire the base method
super.onResume();
}
/* ------------------------------ Methods ------------------------------- */
#SuppressWarnings("deprecation")
private final void createPreference_Activity()
{
// Set the Activity layout
addPreferencesFromResource(R.xml.prefs);
// Get the PreferenceScreen ListView
final ListView lvw = getListView();
// Set the horizontal separator
lvw.setDivider(getResources().getDrawable(R.drawable.list_divider));
lvw.setDividerHeight((1));
// Set the statelist selector
lvw.setSelector(R.drawable.list_item_colors);
// Remove the top and bottom fadings
lvw.setVerticalFadingEdgeEnabled(false);
}
#SuppressLint("NewApi")
private final void createPreference_Fragment()
{
// Create the fragment.
getFragmentManager().beginTransaction().replace
(android.R.id.content, new FRG_Prefs()).commit();
getFragmentManager().executePendingTransactions();
}
}
/src/FRG_Prefs
package com.dergolem.abc;
/* ---------------------------------- Imports ------------------------------- */
import android.annotation.SuppressLint;
import android.graphics.PixelFormat;
import android.preference.PreferenceFragment;
import android.view.View;
import android.widget.ListView;
#SuppressLint("NewApi")
public final class FRG_Prefs
extends PreferenceFragment
{
/* ----------------------------- Overrides ------------------------------ */
#Override
public final void onResume()
{
super.onResume();
addPreferencesFromResource(R.xml.prefs);
init();
}
#Override
public final void onStop()
{
super.onStop();
// Kill the prefence screen, so that it won't be recreated DUPLICATE.
// HORRIBLE, but it's the only way to avoid the PreferenceScreen copycat.
getActivity().finish();
}
/* ------------------------------ Methods ------------------------------- */
private final void init()
{
final View v = getView();
v.setPadding(paddingSize, 0, paddingSize, 0);
// Get the PreferenceScreen ListView
final ListView lvw = (ListView) v.findViewById(android.R.id.list);
// Set the horizontal separator
lvw.setDivider(getResources().getDrawable(R.drawable.list_divider));
lvw.setDividerHeight((1));
// Set the state selector
lvw.setSelector(R.drawable.list_item_colors);
// Remove top and bottom fading
lvw.setVerticalFadingEdgeEnabled(false);
}
}
To show my Preferences:
startActivity(new Intent(ctx, ACT_Prefs.class));
ctx is defined as
Context ctx = getApplicationContext();
since I use it a lot, I define it once and for all.
[EDIT]
By request, I could add a method to make a Fake PreferenceScreen.

The answer above is to difficult to implement, so I've designed my own version.
The layout xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:ads="http://schemas.android.com/apk/res-auto"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:minHeight="?android:attr/listPreferredItemHeight"
android:gravity="center_vertical">
<include layout="#layout/toolbar"/> <!-- This is a custom toolbar (or actionbar), and not necessary -->
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_below="#+id/toolbar"
android:paddingRight="?android:attr/scrollbarSize">
<ScrollView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_below="#layout/toolbar"
android:id="#+id/scrollView" >
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceSmall"
android:text="#string/category_battery"
android:id="#+id/category_misc"
android:layout_marginLeft="#dimen/activity_settings_header_margin" />
<ImageView
android:layout_width="fill_parent"
android:layout_height="2dp"
android:id="#+id/divider"
android:layout_marginLeft="#dimen/activity_settings_margin"
android:layout_below="#+id/category_misc"
android:contentDescription="divider"
android:scaleType="matrix"
android:background="#android:drawable/divider_horizontal_bright"
android:src="#android:drawable/divider_horizontal_bright" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:padding="#dimen/activity_settings_margin">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/textView"/>
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/textView"/>
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/textView"/>
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/textView"/>
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/textView"/>
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/textView"/>
</LinearLayout>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/category_calibration"
android:textAppearance="?android:attr/textAppearanceSmall"
android:id="#+id/category_subjects"
android:layout_marginLeft="#dimen/activity_settings_header_margin"
android:layout_below="#+id/batteryChargeState" />
<ImageView
android:layout_width="fill_parent"
android:layout_height="2dp"
android:id="#+id/divider2"
android:layout_marginLeft="#dimen/activity_settings_margin"
android:layout_below="#+id/category_subjects"
android:contentDescription="divider"
android:scaleType="matrix"
android:background="#android:drawable/divider_horizontal_bright"
android:src="#android:drawable/divider_horizontal_bright" />
<LinearLayout android:layout_width="match_parent"
android:layout_below="#+id/category_subjects"
android:layout_centerVertical="true"
android:layout_height="match_parent"
android:padding="#dimen/activity_settings_margin"
android:orientation="vertical"
android:id="#+id/nextLayout">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/textView"/>
</LinearLayout>
</LinearLayout>
</ScrollView>
</RelativeLayout>
</RelativeLayout>
Toolbar xml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/toolbar"
app:theme="#style/ThemeOverlay.AppCompat.ActionBar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:minHeight="?attr/actionBarSize"
android:background="?attr/colorPrimary"/>
Dimens xml:
<resources>
<!-- Default screen margins, per the Android Design guidelines. -->
<dimen name="activity_horizontal_margin">16dp</dimen>
<dimen name="activity_vertical_margin">16dp</dimen>
<dimen name="activity_settings_margin">24dp</dimen>
<dimen name="activity_settings_header_margin">18dp</dimen>
</resources>
Colors xml:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<color name="orange">#FDA432</color>
<color name="orange_dark">#ffd17731</color>
</resources>
Just use the your way to store the Preferences. I've created a custom preference class that contains private keys so I can't post the code here without breaking it.
The advantage of using a custom layout like this is that you can add your own toolbar with this line as the first element of the first RelativeLayout.
To use the custom toolbar use this piece of code in your onCreate()
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mTitle = mDrawerTitle = getTitle(); // This is for the title when you use a drawer
mToolbar = (Toolbar) findViewById(R.id.toolbar); // This finds the toolbar you've specified using the <include> in the xml
setSupportActionBar(mToolbar); // This sets the toolbar to be used
mToolbar.setBackgroundColor(getResources().getColor(R.color.orange)); // This sets the color of the toolbar
if (Build.VERSION.SDK_INT >= 21) {
getWindow().setStatusBarColor(getResources().getColor(R.color.orange_dark)); // This sets the color of the navigation bar to a darker orange as used for the toolbar, only when this is supported!
}
mToolbar.setNavigationIcon(R.mipmap.ic_launcher); // This makes the icon clickable, to open and close a drawer if you have one
}

Android TextView doesn't show affected text

Ok so... I've been trying to affect text to TextView (because it's meant to show text, right?)
But for some unknown to me reason it refuses to print whatever I put into it.
My application has two activities, the MainAcivity, or a welcoming screen, per se, and a GameActivity (the project is a Domino game).
I create my previously written java objects at the beginning of the GameActivity class, trying then to show player's name within a TextView.
Player player1 = new Player("Hulk");
creates a player with name Hulk, as you can imagine. I have a method within Player.java to return player's name:
player1.getName()
returns string "Hulk"
I then try to set my TextView's text to hulk, first off by creating a handle to it with:
TextView p1v = (TextView) findViewById(R.textviews.p1view);
then doing the following:
p1v.setText("Player 1 : " + player1.toString());
the p1view is defined as follows within game.xml layout:
<LinearLayout
...
<LinearLayout
...
<TextView
android:id="#+textviews/p1view"
android:text="Board"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
</LinearLayout>
</LinearLayout>
I tried p1view.textAppend, tried using android:editable="true". Nothing seems to work.
Funnily enough though, when I try doing the same thing, within MainActivity, it works, as so:
public class
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
with the TextView defined within main.xml as follows:
<TextView
android:id="#+textviews/mainview_player"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
Following are the full codes of the files, just to avoid answers like: Give us the full code D:
GameActivity.java:
package domino.asd;
import LI260.*; import android.app.Activity; import android.os.Bundle;
import android.widget.TextView;
public class GameActivity extends Activity {
private Player player1 = new Player("HULK");
private Player player2 = new Player("CPU");
private Pioche bag = new Pioche();
private Plateau board = new Plateau();
private Game game1 = new Game(bag, board, player1, player2);
TextView p1name = null;
TextView p2name = null;
/**
* Called when the activity is first created.
*
* #param savedInstanceState
*/
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.game);
TextView tv = (TextView) findViewById(R.textviews.p1view);
tv.setText(player1.getName());
} }
game.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:weightSum="10"
>
<!-- Played layout -->
<LinearLayout
android:id="#+drawable/gameview_Scores"
android:layout_width="fill_parent"
android:layout_height="0px"
android:layout_gravity="top"
android:layout_weight="2"
android:layout_marginBottom="10px"
android:orientation="horizontal"
android:background="#ff0000"
android:gravity="center"
>
<Button
android:id="#+buttons/exitButton"
android:text="Exit"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
/>
<Button
android:id="#+buttons/drawButton"
android:text="Draw"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
<Button
android:id="#+buttons/scoresButton"
android:text="Show scores"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
</LinearLayout>
<!-- Board layout -->
<LinearLayout
android:id="#+textviews/gameview_Table"
android:layout_width="fill_parent"
android:layout_height="0px"
android:layout_gravity="center"
android:layout_weight="6"
android:layout_marginBottom="10px"
android:background="#ffff00"
>
<TextView
android:id="#+textviews/p1view"
android:text="Board"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
</LinearLayout>
<!-- At hand layout -->
<LinearLayout
android:id="#+drawable/gameview_Playable"
android:layout_width="fill_parent"
android:layout_height="0px"
android:layout_weight="2"
android:layout_gravity="bottom"
android:background="#ff00ff"
>
<TextView
android:id="#+textviews/gameview_AtHandText"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
</LinearLayout>
</LinearLayout>
MainActivity.java:
package domino.asd;
import LI260.*;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity {
Player p1 = new Player("Hulk");
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
TextView p1view = (TextView) findViewById(R.textviews.mainview_player);
p1view.setText(p1.getName());
}
public void btnClick_Name(View view) {
if (view.getId() == R.buttons.B_EnterName) {
EditText playersname = (EditText) findViewById(R.string.playerNameInput);
Toast.makeText(this, "Your name: " + playersname.getText().toString(), Toast.LENGTH_SHORT).show();
}
setContentView(R.layout.game);
}
}
and lastly main.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center"
>
<EditText
android:id="#+string/playerNameInput"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:inputType="textMultiLine"
android:lines="1"
/>
<TextView
android:id="#+textviews/mainview_player"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
<Button
android:id="#+buttons/B_EnterName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
android:text="Save name and start game."
android:onClick="btnClick_Name"
/>
</LinearLayout>

When you are first loading the activity, you are calling this code:
setContentView(R.layout.main);
TextView p1view = (TextView) findViewById(R.textviews.mainview_player);
p1view.setText(p1.getName());
Yet when the user click's the button you are only calling this code:
setContentView(R.layout.game);
Because you have reset the main content view the child view mainview_player has been destroyed and replaced with a new one when inflated from R.layout.game.
You would need to call this code again to find the new view in the game layout and populate it with your player name:
TextView p1view = (TextView) findViewById(R.textviews.mainview_player);
p1view.setText(p1.getName());
You would be better to look into how activities relate to one another and start a new activity for R.layout.game

myView.setLayoutParams(otherView.getLayoutParams()); Not working, why?

Got my TextView in the xml:
<TextView
android:id="#+id/myTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_weight="1"
android:gravity="left"
android:text="TextView"/>
I want to create multiple TextViews but i want to look them the same as this.
So I tried:
TextView newTextView = new TextView(this);
newTextView.setLayoutParams(myTextView.getLayoutParams());
I think this should get all the layout parameters from myTextView straigthlghly(?) from the xml, and pass them to newTextView to set them.
My problem is: Nothing happens. It does not take effect, why?

here's a sample project which shows that it works.
you can see that it works by looking at the preview of the visual editor , which looks different than what is shown at runtime.
i think that your mistake was that you didn't set 0px (or 0dp, zero is still zero) for the weighted views.
main.xml (layout) :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent" android:id="#+id/container">
<TextView android:id="#+id/textView1" android:layout_width="wrap_content"
android:layout_height="0px" android:text="TextView1"
android:layout_weight="1" android:background="#ffff0000" />
<TextView android:id="#+id/textView2" android:layout_width="wrap_content"
android:layout_height="wrap_content" android:text="TextView2"
android:background="#ff00ff00" />
</LinearLayout>
TestActivity.java :
public class TestActivity extends Activity
{
/** Called when the activity is first created. */
#Override
public void onCreate(final Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final TextView tv1=(TextView)findViewById(R.id.textView1);
final TextView tv2=(TextView)findViewById(R.id.textView2);
final LayoutParams layoutParams=tv1.getLayoutParams();
tv2.setLayoutParams(layoutParams);
// adding textView programatically:
final TextView tv3=new TextView(this);
tv3.setText("textView3");
tv3.setBackgroundColor(0xff0000ff);
tv3.setLayoutParams(layoutParams);
final ViewGroup root=(ViewGroup)findViewById(R.id.container);
root.addView(tv3);
}
}

Android App Null Pointer on Specific Textview

Normally null pointer exceptions seem to be view related - where the wrong layout is targeted.
This is different I reckon. I have four textviews in a layout and one returns a null, the rest work fine. Here is the layout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/text"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="hello" />
<TextView
android:id="#+id/text2"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="stringello2" />
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="ip"
android.id="#+id/iptest"
/>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="hostname"
android:id="#+id/hostname"
/>
</LinearLayout>
And here is the test code:
public class MainActivity extends Activity
{
/** Called when the activity is first created. */
protected TextView text;
protected TextView ip;
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
text = (TextView) findViewById(R.id.text);
text.setText("goodbye");
text = (TextView) findViewById(R.id.hostname);
text.setText("hostname flibble");
// text = (TextView) findViewById(R.id.text2);
text = (TextView) findViewById(R.id.iptest);
text.setText("ip flibble");
}
}
If I switch the comment to the other textview, it works fine. If I target iptest it returns null and raises an exception.
Any ideas why? All four appear in gen and they all reappear if I delete gen and recompile.

in your TextView Tag
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="ip"
android.id="#+id/iptest"
/>
you had taken a .(dot) instead of :(colon)
android.id="#+id/iptest"
shoulb de like this
android:id="#+id/iptest"
Moreover please clean your project regularly.

your R class is not holding iptest reference . android.id="#+id/iptest" is wrong . It should be android:id