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How to avoid crashing for an listview android app [closed]

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I build an android app with the help of an tutorial.
This is the MainActivity.java:-
package com.example.listdisplay;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.ArrayAdapter;
import android.widget.ListView;
public class MainActivity extends Activity {
// Array of strings...
String[] mobileArray = {"Android","IPhone","WindowsMobile","Blackberry",
"WebOS","Ubuntu","Windows7","Max OS X", "PHP", "Java", "HTML", "CSS", "JavaScript","MySQL"};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ArrayAdapter adapter = new ArrayAdapter<String>(this,
R.layout.activity_listview, mobileArray);
ListView listView = (ListView) findViewById(R.id.mobile_list);
listView.setAdapter(adapter);
}
}
This is the activity_main.xml:-
<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">
<ListView
android:id="#+id/mobile_list"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</ListView>
</LinearLayout>
This is the activity_listview.xml:-
<?xml version="1.0" encoding="utf-8"?>
<!-- Single List Item Design -->
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/label"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="20dip"
android:textSize="16dip"
android:textStyle="bold"
android:orientation="horizontal">
</TextView>
When I change the textview to any other view like cardview and more things. The app is going to crashed.
I want to do more styling with cardview and layout. Like i also tried with the linearlayout.I inserted this textview with an button in linear layout. But, it is still going to crash.
Please help me.

You can't change the TextView from activity_listview.xml because ArrayAdapterconstructor expects a Layout with an only EditText.
If you want to modify that, you have to implement a custom ArrayAdaptermaking a class that extends from it.
You can follow next Medium tutorial to achieve this.
https://medium.com/mindorks/custom-array-adapters-made-easy-b6c4930560dd
If you want to add a Button or something else, you need the custom ArrayAdapter.

If you want to do more styling with card view so you don't need change text view to card view just simply write your code like below code...
<androidx.cardview.widget.CardView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="5dp"
app:cardCornerRadius="5dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="5dp">
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/label"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="5dip"
android:textSize="16dip"
android:textStyle="bold"
android:orientation="horizontal">
</TextView>
</LinearLayout>
</androidx.cardview.widget.CardView>

Create your custom xml file:
<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView 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:orientation="vertical"
android:padding="8dp">
<TextView
android:id="#+id/label"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:text="This is just text" />
</LinearLayout>
</androidx.cardview.widget.CardView>
Important part is android:id="#+id/label" in TextView.
And add the R.id.label to third parameter of ArrayAdapter, like that:
ArrayAdapter adapter = new ArrayAdapter<String>(this,
R.layout.activity_listview, R.id.label, mobileArray);

Android Screen Slide action

I am just starting to learn android java in Android Studio.
And I have bum into a question related to screen slide action.
I wanted to create a screen slide action that allow me to have additional options beside my basic layout's option, after the chose of the additional option I will return to my basic layout.
The perfect example that could represent my idea would be the Google Calculator, when user need advance Math symbol, it has a green layout that show up while user sliding the right's edge to the left, and after user choose one Math Symbol, it will return to its basic layout.
This is the screen shot of the calculator,photo belong to the internet
I am not very good at explaining, I hope you guys understand what I am trying to approach.

I have it working using SlidingPaneLayout. Let me know if this works.
XML
<android.support.v4.widget.SlidingPaneLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/SlidingPanel"
android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
android:id="#+id/base"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#2196F3"
android:orientation="vertical">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:text="Hello SlidingPaneLayout!" />
</RelativeLayout>
<RelativeLayout
android:id="#+id/slider"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginLeft="20dp"
android:background="#F44336"
android:elevation="50dp">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:text="Hello SlidingPaneLayout!" />
</RelativeLayout>
</android.support.v4.widget.SlidingPaneLayout>
Activity
import android.os.Bundle;
import android.support.v4.content.ContextCompat;
import android.support.v4.widget.SlidingPaneLayout;
import android.support.v7.app.AppCompatActivity;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
SlidingPaneLayout slidingPaneLayout = (SlidingPaneLayout) findViewById(R.id.SlidingPanel);
slidingPaneLayout.setSliderFadeColor(ContextCompat.getColor(this, android.R.color.transparent));
slidingPaneLayout.openPane();
}
}

Android. How to add transparent image over another image

I know how to do this via a surfaceView and I'm wondering if I should go down that rout.
I'm simply trying to create a splashscreen that has a fullscreen image with an opaque image laid over the top (after a short delay). I can't work out how this is done in XML code.
This is what I have......
<?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"
>
<ImageView
android:id="#+id/lightDot"
android:src="#drawable/splashlight"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#null"
/>
<ImageView
android:id="#+id/bGround"
android:src="#drawable/splash"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
So my 'lightDot' object is semi-transparent and I want to overlay this on top of my bGround resource after a short delay.
This is my code:
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
public class SplashAct extends Activity implements OnClickListener{
Button mainButton;
Button lightDot;
ImageView background;
ImageView light;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.splashscreen);
background = (ImageView)findViewById(R.id.bGround);
light = (ImageView)findViewById(R.id.lightDot);
background.setOnClickListener(this);
}
#Override
public void onClick(View arg0) {
//finish();
Intent toMainGame = new Intent(this, ActOptions.class);
startActivity(toMainGame);
}
}
Thank you.

What you want is a FrameLayout.
Child views are drawn in a stack, with the most recently added child on top.
You can get more fancy with where the overlays go using layout_gravity, but it sounds like this is all you need.
<FrameLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<ImageView
android:id="#+id/image"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="#drawable/image" >
</ImageView>
<ImageView
android:id="#+id/overlay"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="#drawable/overlay"/>
</FrameLayout>

Use Relative layout not linear layout.
This allows you to place views ontop of one another, as opposed to in a linear list.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<ImageView
android:id="#+id/lightDot"
android:src="#drawable/splashlight"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#null"
/>
<ImageView
android:id="#+id/bGround"
android:src="#drawable/splash"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
</RelativeLayout>
To make the Dot appear after time, use android:visiblity="INVISIBLE" in the xml. (so it starts invisible)
then use light.setVisiblity(View.VISIBLE); in your code.

You could use a LayerDrawable
Define a simple LinearLayout
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/splash_layout"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
In your Activity class:
LinearLayout layout = (LinearLayout) findViewById(R.id.splash_layout);
Drawable drawableLayers[] = new Drawable[] {getResources().getDrawable(R.drawable.splash), getResources().getDrawable(R.drawable.splashlight)};
// ^ The order of drawables is important: The above line overlays splashlight on top of splash.
LayerDrawable layerDrawable = new LayerDrawable(drawableLayers);
layout.setBackgroundDrawable(layerDrawable);

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:id="#+id/ll"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
***android:background="#drawable/splash"*** >
// Try this for invisible
iv.getBackground().setAlpha(0);
//Try this for visible
iv.getBackground().setAlpha(255);
//What great about this is that you could create a loop
//to slowly increment the alpha, creating a fade effect instead of
//invisible to visible.

Opening a new window from within tabhost

Hey im developing my first proper app for android and have run into 2 small hickups and was hoping for some help basicaly the main problem is that i cant seem to change to a new view from within tabhost. I have 4 tabs 2 just show a simple xml file the 3rd shows a series of pictures which i want to make clickable so that they expand out into player bio's. atm im attempting to do this in the following way but it just causes my application to crash
package com.BPRUFC;
import android.app.TabActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.TabHost;
public class BPRUFCAppActivity extends TabActivity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
TabHost mTabHost = getTabHost();
mTabHost.addTab(mTabHost.newTabSpec("tab_test1").setIndicator("Fixtures").setContent(R.id.fixtures));
mTabHost.addTab(mTabHost.newTabSpec("tab_test2").setIndicator("Results").setContent(R.id.results));
mTabHost.addTab(mTabHost.newTabSpec("tab_test3").setIndicator("Players").setContent(R.id.bio));
mTabHost.addTab(mTabHost.newTabSpec("tab_test4").setIndicator("Tour").setContent(R.id.tour));
mTabHost.setCurrentTab(0);
int days = 184;
String tour2 = getString(R.string.tour, days);
}
public void clicked(View view)
{
Intent myIntent = new Intent(BPRUFCAppActivity.this, PlayerBio.class);
BPRUFCAppActivity.this.startActivity(myIntent);
}
}
main Xml stopped after first pic as its quite long
<?xml version="1.0" encoding="utf-8"?>
<TabHost xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#android:id/tabhost"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TabWidget
android:id="#android:id/tabs"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
<FrameLayout
android:id="#android:id/tabcontent"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ScrollView
android:id="#+id/ScrollView01"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<TextView
android:id="#+id/fixtures"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:text="#string/fixtures" />
</ScrollView>
<TextView
android:id="#+id/results"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:text="Results go here" />
<ScrollView
android:id="#+id/ScrollView02"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<RelativeLayout
android:id="#+id/bio"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ImageView android:layout_width="90dip"
android:layout_height="90dip"
android:id="#+id/imageView1"
android:src="#drawable/forrest"
android:onClick="clicked"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_marginLeft="10dp"
android:layout_marginTop="10dp">
</ImageView>
Thanks in advance and im sure its a noob mistake

I fixed this myself. I was going about it the wrong way nesting too many layouts. I changed it all so that each tab has 1 frame layout and this is then modified accordingly it now behaves properly.

Showing empty view when ListView is empty

For some reason the empty view, a TextView in this case, always appears even when the ListView is not empty. I thought the ListView would automatically detect when to show the empty view.
<RelativeLayout android:id="#+id/LinearLayoutAR"
android:layout_height="fill_parent"
android:layout_width="fill_parent">
<ListView android:id="#+id/ARListView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"></ListView>
<ProgressBar android:id="#+id/arProgressBar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"></ProgressBar>
<!-- Here is the view to show if the list is emtpy -->
<TextView android:id="#id/android:empty"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="No Results" />
</RelativeLayout>
How can I hook up the empty view properly?

When you extend FragmentActivity or Activity and not ListActivity, you'll want to take a look at:
ListView.setEmptyView()

It should be like this:
<TextView android:id="#android:id/empty"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="No Results" />
Note the id attribute.

As appsthatmatter says, in the layout something like:
<ListView android:id="#+id/listView" ... />
<TextView android:id="#+id/emptyElement" ... />
and in the linked Activity:
this.listView = (ListView) findViewById(R.id.listView);
this.listView.setEmptyView(findViewById(R.id.emptyElement));
Does also work with a GridView...

I tried all the above solutions.I came up solving the issue.Here I am posting the full solution.
The xml file:
<RelativeLayout
android:id="#+id/header_main_page_clist1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="20dp"
android:paddingBottom="10dp"
android:background="#ffffff" >
<ListView
android:id="#+id/lv_msglist"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:divider="#color/divider_color"
android:dividerHeight="1dp" />
<TextView
android:id="#+id/emptyElement"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:text="NO MESSAGES AVAILABLE!"
android:textColor="#525252"
android:textSize="19.0sp"
android:visibility="gone" />
</RelativeLayout>
The textView ("#+id/emptyElement") is the placeholder for the empty listview.
Here is the code for java page:
lvmessage=(ListView)findViewById(R.id.lv_msglist);
lvmessage.setAdapter(adapter);
lvmessage.setEmptyView(findViewById(R.id.emptyElement));
Remember to place the emptyView after binding the adapter to listview.Mine was not working for first time and after I moved the setEmptyView after the setAdapter it is now working.
Output:

I highly recommend you to use ViewStubs like this
<FrameLayout
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="1" >
<ListView
android:id="#android:id/list"
android:layout_width="fill_parent"
android:layout_height="fill_parent" />
<ViewStub
android:id="#android:id/empty"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout="#layout/empty" />
</FrameLayout>
See the full example from Cyril Mottier

<ListView android:id="#+id/listView" ... />
<TextView android:id="#+id/empty" ... />
and in the linked Activity:
this.listView = (ListView) findViewById(R.id.listView);
this.listView.setEmptyView(findViewById(R.id.empty));
This works clearly with FragmentActivity if you are using the support library. Tested this by building for API 17 i.e. 4.2.2 image.

Activity code, its important to extend ListActivity.
package com.example.mylistactivity;
import android.app.ListActivity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import com.example.mylistactivity.R;
// It's important to extend ListActivity rather than Activity
public class MyListActivity extends ListActivity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.mylist);
// shows list view
String[] values = new String[] { "foo", "bar" };
// shows empty view
values = new String[] { };
setListAdapter(new ArrayAdapter<String>(
this,
android.R.layout.simple_list_item_1,
android.R.id.text1,
values));
}
}
Layout xml, the id in both views are important.
<?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">
<!-- the android:id is important -->
<ListView
android:id="#android:id/list"
android:layout_width="fill_parent"
android:layout_height="fill_parent"/>
<!-- the android:id is important -->
<TextView
android:id="#android:id/empty"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:text="i am empty"/>
</LinearLayout>

Just to add that you don't really need to create new IDs, something like the following will work.
In the layout:
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#android:id/list"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#android:id/empty"
android:text="Empty"/>
Then in the activity:
ListView listView = (ListView) findViewById(android.R.id.list);
listView.setEmptyView(findViewById(android.R.id.empty));

I had this problem. I had to make my class extend ListActivity rather than Activity, and rename my list in the XML to android:id="#android:id/list"

A programmatically solution will be:
TextView textView = new TextView(context);
textView.setId(android.R.id.empty);
textView.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
textView.setText("No result found");
listView.setEmptyView(textView);

First check the list contains some values:
if (list.isEmpty()) {
listview.setVisibility(View.GONE);
}
If it is then OK, otherwise use:
else {
listview.setVisibility(View.VISIBLE);
}