Develop Reference

Dynamically populated spinner is not returning a view and I am unable to select items

This is the Select.java file that populates the spinners
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
public class select extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_select);
final Spinner s1 = (Spinner) findViewById(R.id.s1);
ArrayAdapter s1adapter = ArrayAdapter.createFromResource(this, R.array.s1,R.layout.spin);
s1adapter.setDropDownViewResource(R.layout.spin);
s1.setAdapter(s1adapter);
final ArrayList<String> array = new ArrayList<>();
s1.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
array.add("1");
long iid = parent.getSelectedItemId();
if (iid == 0) {
array.clear();
array.add("id 1");
} else if (iid == 1) {
array.clear();
array.add("id 2");
array.add("id 3");
}
}
#Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
Spinner s2 = (Spinner) findViewById(R.id.s2);
Adapter s2adapter = new Adapter(this,R.layout.spin,array);
s2.setAdapter(s2adapter);
final String l = null;
s2.setSelection(0);
s2.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
Intent less = new Intent(getBaseContext(),less.class);
Toast.makeText(getBaseContext(),"in",Toast.LENGTH_SHORT);
if (parent.getItemAtPosition(position).equals("id 1")) {
less.putExtra("lesson_1", l);
Toast.makeText(getBaseContext(),"in",Toast.LENGTH_SHORT);
} else if (parent.getItemAtPosition(position).equals("id 2")) {
less.putExtra("lesson_2", l);
} else if (parent.getItemAtPosition(position).equals("id 3")) {
less.putExtra("lesson_3", l);
}
startActivity(less);
}
#Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
}
}
The following is spin.xml the custom view for spinner
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/testing"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="top"
android:singleLine="true"
android:textSize="20sp"
android:typeface="sans"
android:textStyle="bold"
android:textColor="#android:color/white"
android:background="#android:color/black"/>
The following is the adapter to inflate the view in the spinner
import android.content.Context;
import android.text.Layout;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;
import java.util.ArrayList;
public class Adapter extends ArrayAdapter<String> {
Context c;
ArrayList<String> list;
public Adapter(Context context, int resource, ArrayList<String> list) {
super(context,R.layout.spin, list);
this.c=context;
this.list=list;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
if(convertView==null)
{
LayoutInflater inf =(LayoutInflater) c.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView=inf.inflate(R.layout.spin,null);}
TextView a =(TextView)convertView.findViewById(R.id.testing);
a.setText(list.get(position));
return convertView;
}
#Override
public View getDropDownView(int position, View convertView, ViewGroup parent) {
if(convertView==null)
{
LayoutInflater inf =(LayoutInflater) c.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView=inf.inflate(R.layout.spin,null);}
TextView a =(TextView)convertView.findViewById(R.id.testing);
a.setText(list.get(position));
return convertView;
}
}
The spinner doesn't show any items initially but does on click. Items are not getting selected. Proof is the makeToast isn't working.
Kindly suggest something.

try this
allusers.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
// clicked item will be shown as spinner
Toast.makeText(getApplicationContext(),""+parent.getItemAtPosition(position).toString(),Toast.LENGTH_SHORT).show();
}
#Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
Refer here:-
http://coderzpassion.com/android-spinner-get-data-from-sqlite-database/

How to select item in the list view programmatically

I have an ArrayList<String> List which contains some items from the listview all_list. How can I select these items in the list view all_list programmatically by checking the ArrayList<String> List contents?
for e.g., listview all_list contains [0] apple
[1] orange
[2] banana
In ArrayList<String> List, I have orange so I want item on position 1 on the listview all_list to be selected (highlighted) automatically.
I have tried using all_list.setItemChecked(), but it does nothing and shuts down the application. I am performing the operation after listing the adapter.

set an onItemClickListener to the listview such that on click, you set a boolean flag that sets the checkbox in each row to selected. then call notifyDataSetChanged()

Try this
MainActivity.java
package com.example.multiseekbar;
import java.util.ArrayList;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;
public class MainActivity extends Activity {
ListView listView1;
ArrayList<ModelClass> modelClass = new ArrayList<ModelClass>();
FruitSelectAdapter adapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
modelClass.add(new ModelClass("Orange", true));
modelClass.add(new ModelClass("Apple", false));
modelClass.add(new ModelClass("Banana", false));
modelClass.add(new ModelClass("Grapes", false));
listView1 = (ListView) findViewById(R.id.listView1);
adapter = new FruitSelectAdapter(MainActivity.this, modelClass);
listView1.setAdapter(adapter);
listView1.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
// TODO Auto-generated method stub
if(modelClass.get(arg2).isSelected()){
modelClass.get(arg2).setSelected(false);
}else{
modelClass.get(arg2).setSelected(true);
}
adapter.notifyDataSetChanged();
}
});
}
}
activity_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.multiseekbar.MainActivity" >
<ListView
android:id="#+id/listView1"
android:layout_width="match_parent"
android:layout_height="fill_parent"
>
</ListView>
</RelativeLayout>
FruitSelectAdapter.java
package com.example.multiseekbar;
import java.util.ArrayList;
import android.app.Activity;
import android.content.Context;
import android.graphics.Color;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.CheckBox;
import android.widget.LinearLayout;
import android.widget.TextView;
public class FruitSelectAdapter extends BaseAdapter
{
private Activity activity;
private LayoutInflater inflater;
private ArrayList<ModelClass> modelClass=null;
public FruitSelectAdapter(Activity activity, ArrayList<ModelClass> modelClass) {
this.activity = activity;
this.modelClass = modelClass;
}
#Override
public int getCount() {
// TODO Auto-generated method stub
return modelClass.size();
}
#Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return modelClass.get(position);
}
#Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
final ViewHolder holder;
if (inflater == null)
inflater = (LayoutInflater) activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if (convertView == null) {
holder =new ViewHolder();
convertView = inflater.inflate(R.layout.row1, null);
holder.txtFruitName = (TextView)convertView.findViewById(R.id.txtFruitName);
holder.cbFruitSelectStatus = (CheckBox)convertView.findViewById(R.id.cbFruitSelectStatus);
holder.linLayBackground = (LinearLayout) convertView.findViewById(R.id.linLayBackground);
convertView.setTag(holder);
}else{
holder = (ViewHolder)convertView.getTag();
}
holder.txtFruitName.setText(modelClass.get(position).getFruitName());
holder.cbFruitSelectStatus.setChecked(modelClass.get(position).isSelected());
if(modelClass.get(position).isSelected()){
holder.linLayBackground.setBackgroundColor(Color.parseColor("#80ccff"));
}else{
holder.linLayBackground.setBackgroundColor(Color.parseColor("#FFFFFF"));
}
return convertView;
}
class ViewHolder{
TextView txtFruitName;
CheckBox cbFruitSelectStatus;
LinearLayout linLayBackground;
}
}
row1.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:id="#+id/linLayBackground"
android:layout_height="70dp"
android:orientation="horizontal"
>
<TextView
android:id="#+id/txtFruitName"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="Fruit name"
android:layout_weight="1"
android:textSize="16sp"
android:textColor="#000000" />
<CheckBox
android:id="#+id/cbFruitSelectStatus"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:clickable="false"
android:focusable="false"
android:focusableInTouchMode="false" />
</LinearLayout>
ModelClass.java
package com.example.multiseekbar;
public class ModelClass {
String fruitName;
boolean isSelected=false;
public ModelClass(String fruitName, boolean isSelected) {
this.fruitName = fruitName;
this.isSelected = isSelected;
}
public String getFruitName() {
return fruitName;
}
public void setFruitName(String fruitName) {
this.fruitName = fruitName;
}
public boolean isSelected() {
return isSelected;
}
public void setSelected(boolean isSelected) {
this.isSelected = isSelected;
}
}

Not able to detect the button clicked on gridview

I am developing a simple calculator android app that will evaluate the expression and display the result in a textbox.But i am not able to detect the button clicks.I dont want to define my own Adapter.Check out my codes :
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"
android:padding="30dp"
>
<EditText
android:id="#+id/text"
android:layout_width="match_parent"
android:layout_height="60dp"
android:hint="#string/expression"
/>
<GridView
android:id="#+id/grid"
android:numColumns="4"
android:columnWidth="20dp"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:paddingTop="100dp"
></GridView>
</LinearLayout>
gridcontent.xml :
<?xml version="1.0" encoding="utf-8"?>
<Button
android:layout_width="70dp"
android:layout_height="70dp"
android:clickable="true"
xmlns:android="http://schemas.android.com/apk/res/android"/>
MainActivity.java :
package com.example.calculator;
import java.util.ArrayList;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.GridView;
import android.widget.Toast;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ArrayList<Character> arr = new ArrayList<Character>();
String str = "789/456*123-.0=+";
for(int i = 0;i<str.length();i++)
arr.add(str.charAt(i));
ArrayAdapter<Character> adapter = new ArrayAdapter<>(this, R.layout.gridcontent, arr);
GridView grid = (GridView) findViewById(R.id.grid);
grid.setAdapter(adapter);
grid.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// TODO Auto-generated method stub
Toast.makeText(MainActivity.this, position + "done", Toast.LENGTH_SHORT).show();
}
});
}
}
Note : I am new to android and playing around with stuff :)
Thanks for your help in advance

Create Adapter for grid like
Class Gridlistadapter extends ArrayAdapter<Character>
{
public Gridlistadapter (Context context, int resource,
List<Character> objects) {
super(context, resource, objects);
// TODO Auto-generated constructor stub
this.context = context;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
View view = convertView;
if (view == null) {
LayoutInflater inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
view = inflater.inflate(R.layout.gridcontent, null);
}
Character data = getItem(position);
Button button1= (Button) view.findViewById(R.id.button1);
button1.setText(""+data);
button1.setOnClickListener(new Listener(position));
return view;
}
class listener implements OnClickListener {
private int position;
listener(int position) {
this.position = position;
}
#SuppressLint("UseValueOf")
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
Toast.makeText(context, position + "done", Toast.LENGTH_SHORT).show();
}
}
}
}
package com.example.calculator;
import java.util.ArrayList;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.GridView;
import android.widget.Toast;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ArrayList<Character> arr = new ArrayList<Character>();
String str = "789/456*123-.0=+";
for(int i = 0;i<str.length();i++)
arr.add(str.charAt(i));
Gridlistadapter adapter = new Gridlistadapter (this, R.layout.gridcontent, arr);
GridView grid = (GridView) findViewById(R.id.grid);
grid.setAdapter(adapter);
grid.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// TODO Auto-generated method stub
Toast.makeText(MainActivity.this, position + "done", Toast.LENGTH_SHORT).show();
}
});
}
}

Custom ListView not showing any items

I am trying to display a custom listview but nothing appears.
My activity:
import java.util.ArrayList;
import org.json.JSONArray;
import org.json.JSONException;
import com.example.elnoorgeh.ServerAPI;
import android.app.Fragment;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.webkit.WebView.FindListener;
import android.widget.AdapterView;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;
public class BlogFragment extends Fragment {
JSONArray jArray;
TextView title;
RelativeLayout layout;
int previousID = 0;
int currentID = 0;
ArrayList<String> titles;
ArrayList<String> contents;
ListView list;
public BlogFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_blog, container,
false);
new AsyncFetch().execute();
return rootView;
}
private class AsyncFetch extends AsyncTask<Object, Object, Object> {
#Override
protected Object doInBackground(Object... params) {
// TODO Auto-generated method stub
jArray = new JSONArray();
jArray = ServerAPI.getData();
titles = new ArrayList<String>();
contents = new ArrayList<String>();
for (int i = 0; i < jArray.length(); i++) {
String blogTitle = null;
String content = null;
try {
blogTitle = jArray.getJSONObject(i).getString("title");
content = jArray.getJSONObject(i).getString("content");
titles.add(blogTitle);
contents.add(content);
} catch (JSONException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
System.out.println(blogTitle);
System.out.println(content);
}
// display(titles, contents);
return null;
}
protected void onPostExecute(Object result) {
layout = (RelativeLayout) getView().findViewById(R.id.blogPage);
layout.removeAllViews();
CustomList adapter = new CustomList(getActivity(), titles);
list = new ListView(getActivity());
System.out.println("list done");
list.setAdapter(adapter);
list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
Toast.makeText(getActivity(),
"You Clicked at " + titles.get(position),
Toast.LENGTH_SHORT).show();
}
});
}
}
public void display(ArrayList<String> t, ArrayList<String> c) {
}
}
Custom ListView class:
import java.util.ArrayList;
import android.app.Activity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;
public class CustomList extends ArrayAdapter<String> {
private final Activity context;
private final ArrayList<String> web;
// private final Integer[] imageId;
public CustomList(Activity context, ArrayList<String>web) {
super(context, R.layout.fragment_listview);
this.context = context;
this.web = web;
// this.imageId = imageId;
}
#Override
public View getView(int position, View view, ViewGroup parent) {
LayoutInflater inflater = context.getLayoutInflater();
View rowView = inflater.inflate(R.layout.fragment_listview, null, true);
TextView txtTitle = (TextView) rowView.findViewById(R.id.txt);
ImageView imageView = (ImageView) rowView.findViewById(R.id.img);
txtTitle.setText((CharSequence) web.get(position));
// imageView.setImageResource(imageId[position]);
return rowView;
}
}
fragment_blog:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/blogPage"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<ListView
android:id="#+id/list"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</ListView>
<TextView
android:id="#+id/txtLabel"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:maxLines="20"
android:singleLine="false"
android:textSize="16dp" />
</RelativeLayout>
fragment_listview:
<?xml version="1.0" encoding="utf-8"?>
<TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<TableRow>
<ImageView
android:id="#+id/img"
android:layout_width="50dp"
android:layout_height="50dp" />
<TextView
android:id="#+id/txt"
android:layout_width="wrap_content"
android:layout_height="50dp" />
</TableRow>
</TableLayout>
I can't find any errors or notice something irregular, so why is that happening?

you should extend BaseAdapter and implement abstract methods
#Override
public int getCount() {
return web.size();
}
#Override
public Object getItem(int position) {
return web.get(position);
}
#Override
public long getItemId(int position) {
return 0;
}
also you might change
txtTitle.setText((CharSequence) web.get(position));
to
txtTitle.setText((CharSequence) getItem(position));
now your adapter don't know size of web array
edit:
you can get one inflater in constructor and keep in class, no need to getting inflater each time (little bit better for perfomance)
LayoutInflater inflater = context.getLayoutInflater();
edit 2:
localhost put proper comment - you are removing all Views from RelativeLayout, also ListView, and creating new ListView without adding to Relative. keeping reference will not auto-add View
protected void onPostExecute(Object result) {
layout = (RelativeLayout) getView().findViewById(R.id.blogPage);
layout.removeView(getView().findViewById(R.id.txtLabel);
//assuming you need to remove only txtLabel
CustomList adapter = new CustomList(getActivity(), titles);
list.setAdapter(adapter);
list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
Toast.makeText(getActivity(),
"You Clicked at " + titles.get(position),
Toast.LENGTH_SHORT).show();
}
});
}

Android gallery get image name

In the below code i have created a gallery object and also have included a image view,on click of image how to get the image name and load it in image view.I have also included main.xml
package HelloGallery.com;
import android.app.Activity;
import android.content.Context;
import android.content.res.TypedArray;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageView;
import android.widget.Toast;
public class HelloGalleryActivity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final ImageView iv=(ImageView) findViewById(R.id.imageView1);
iv.setVisibility(View.INVISIBLE);
Gallery g = (Gallery) findViewById(R.id.gallery);
g.setAdapter(new ImageAdapter(this));
g.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView parent, View v, int position, long id) {
Toast.makeText(HelloGalleryActivity.this, "" + position, Toast.LENGTH_SHORT).show();
iv.setVisibility(View.VISIBLE);
iv.setsource("android:src="#drawable/"+imagename); //how to do this
}
});
}
public class ImageAdapter extends BaseAdapter {
int mGalleryItemBackground;
private Context mContext;
private Integer[] mImageIds = {
R.drawable.sample_1,
R.drawable.sample_2,
R.drawable.sample_3
};
public ImageAdapter(Context c) {
mContext = c;
TypedArray a = obtainStyledAttributes(R.styleable.HelloGallery);
mGalleryItemBackground = a.getResourceId(
R.styleable.HelloGallery_android_galleryItemBackground, 0);
a.recycle();
}
public int getCount() {
return mImageIds.length;
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ImageView i = new ImageView(mContext);
i.setImageResource(mImageIds[position]);
i.setLayoutParams(new Gallery.LayoutParams(150, 100));
i.setScaleType(ImageView.ScaleType.FIT_XY);
i.setBackgroundResource(mGalleryItemBackground);
return i;
}
/* public View getView(int arg0, View arg1, ViewGroup arg2) {
// TODO Auto-generated method stub
return null;
}*/
}
}
Main.mxml
<?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"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/hello"
/>
<Gallery xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/gallery"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
<ImageView android:layout_width="wrap_content" android:id="#+id/imageView1" android:layout_height="wrap_content" ></ImageView>
</LinearLayout>

Try this,
Drawable d=getResources().getDrawable(R.drawable.icon);
iv.setImageDrawable(d);