I am studying ApiDemos sample in SDK
and trying to separate Menu example(App/Menu/Inflate from Menu-MenuInflateFromXml.java).
package my.android.Menu;
import my.android.Menu.R;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.ArrayAdapter;
import android.widget.LinearLayout;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;
public class MyMenu extends Activity {
/**
* Different example menu resources.
*/
private static final int sMenuExampleResources[] = {
R.menu.title_only, R.menu.title_icon, R.menu.submenu, R.menu.groups,
R.menu.checkable, R.menu.shortcuts, R.menu.order, R.menu.category_order,
R.menu.visible, R.menu.disabled
};
/**
* Names corresponding to the different example menu resources.
*/
private static final String sMenuExampleNames[] = {
"Title only", "Title and Icon", "Submenu", "Groups",
"Checkable", "Shortcuts", "Order", "Category and Order",
"Visible", "Disabled"
};
/**
* Lets the user choose a menu resource.
*/
private Spinner mSpinner;
/**
* Shown as instructions.
*/
private TextView mInstructionsText;
/**
* Safe to hold on to this.
*/
private Menu mMenu;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Create a simple layout
LinearLayout layout = new LinearLayout(this);
layout.setOrientation(LinearLayout.VERTICAL);
// Create the spinner to allow the user to choose a menu XML
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_spinner_item, sMenuExampleNames);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
mSpinner = new Spinner(this);
// When programmatically creating views, make sure to set an ID
// so it will automatically save its instance state
mSpinner.setId(R.id.spinner);//Error Line
mSpinner.setAdapter(adapter);
setContentView(R.layout.main);
}
}
IDE show this error "spinner cannot be resolved or is not a field", i can't go head.
i did't see any XML file which include "spinner".
As per Tim's comment above:
put this line in your onCreate()
mSpinner = (Spinner) findViewById(R.id.spinner);
You should move your setContentView(R.layout.main); right below of the super.onCreate(savedInstanceState); It's necessary to set the content of your activity before using its Views and you don't need to instanciate the spinner View programmatically. Simply use the Spinner defined at the main.xml file (I Assume you have a Spinner inside this file).
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// Create a simple layout
LinearLayout layout = new LinearLayout(this);
layout.setOrientation(LinearLayout.VERTICAL);
// Create the spinner to allow the user to choose a menu XML
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_spinner_item, sMenuExampleNames);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
//mSpinner = new Spinner(this);
// When programmatically creating views, make sure to set an ID
// so it will automatically save its instance state
// mSpinner.setId(R.id.spinner);//Error Line
mSpinner = (Spinner) findViewById(R.id.you_spinner_id); //you_spinner_id must be defined at main.xml
mSpinner.setAdapter(adapter);
}
Related
The title of this post says it all.
This code works without any problems:
package abc.AvailableCars;
import android.graphics.Color;
import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public class carListActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.car_list_layout);
final ListView carListview = (ListView) findViewById(R.id.list_view);
final Button dButton = (Button) findViewById(R.id.disable_button);
String[] cars = {"Maxima GXE", "Passat", "Focus SE", "Mazda6", "Avalon", :Sentra GXE"};
final List<String> list_of_cars = new ArrayList<String>(Arrays.asList(cars));
final ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>
(this, android.R.layout.simple_list_item_1, list_of_cars);
carListview.setAdapter(arrayAdapter);
dButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int chosenRow = 3;
carListview.getChildAt(3).setEnabled(false);
carListview.getChildAt(3).setBackgroundColor(Color.parseColor("#3f51b5"));
}
});
}
}
This is in my listview .xml file:
<Button
android:id="#+id/disable_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Disable A Row"
/>
But, when I comment-out everything that belongs to the button, like below, and the Car List class is called, the app crashes with the error in the Logcat:
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.view.View.setEnabled(boolean)' on a null object reference:
final ListView carListview = (ListView) findViewById(R.id.list_view);
//final Button dButton = (Button) findViewById(R.id.disable_button);
String[] cars = {"Maxima GXE", "Passat", "Focus SE", "Mazda6", "Avalon"};
final List<String> list_of_cars = new ArrayList<String>(Arrays.asList(cars));
final ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>
(this, android.R.layout.simple_list_item_1, list_of_cars);
carListview.setAdapter(arrayAdapter);
//dButton.setOnClickListener(new View.OnClickListener() {
//#Override
//public void onClick(View v) {
int chosenRow = 3;
carListview.getChildAt(chosenRow).setEnabled(false);
carListview.getChildAt(chosenRow).setBackgroundColor(Color.parseColor("#3f51b5"));
}
//});
}
//}
I'm not an Android newbie anymore, but this is eluding me.
I want the chosen row to be disabled and the color set as soon as the listview is shown.
How can I do this programmatically without a button?
I have tried every variation I can think of, getView(), even a fake click.
Just in case it makes a difference, this code is in a separate class and file than the MainActivity.java file, and is called in that file.
There has to be a simple answer. What do I need to change?
Please be verbose.
Thank you.
You are calling carListview.getChildAt(chosenRow) when you set up your list view, in onCreate. Your list view is not ready yet. Try moving this code to your onResume - should look something like this:
#Override
public void onResume(){
super.onResume();
arrayAdapter.notifyDataSetChanged();
int chosenRow = 3;
carListview.getChildAt(chosenRow).setEnabled(false);
carListview.getChildAt(chosenRow).setBackgroundColor(Color.parseColor("#3f51b5"));
}
This is a pretty simple case - your chosenRow number is generated by you. You might need a custom Adapter if you need it to be algorithmic or user-driven. Have a look at this tutorial.
From my understanding, since listViews are views, they have to be Overridden for some things to be changed in them.
I chose not to disable the required rows, but check for them in code.
The complete code that works is below.
Some credit goes to Raghunandan for his/her answer at-
Android - Change background color of specific item of ListView
Again, sorry, but the indentation of the code wouldn't work correctly for some reason.
import android.graphics.Color;
import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public class CarListActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.car_list_layout);
final ListView carListview = (ListView) findViewById(R.id.list_view);
String[] cars = {"European Cars:", "Mercedes", "Passat", "Bently", "Porsche", "BMW", "Yugo","Land Rover",
"Japanese Cars:", "Maxima GXE", "Mazda6", "Avalon", "Toyota", "Honda", ""};
final List<String> list_of_cars = new ArrayList<String>(Arrays.asList(cars));
final ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>
(this, android.R.layout.simple_list_item_1, list_of_cars);
//------------------------------------------
carListview.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, list_of_cars) {
// Since listViews are views, they have to be Overrdden for some things to be changed in them.
#Override
public View getView(int rowPosition, View convertView, ViewGroup parent) {
View row = super.getView(rowPosition, convertView, parent);
//------------------------------------------
// This works. I have only tried this for two rows, the two I wanted. I expected this line to crash the app, but it didn't.
if(getItem(rowPosition).equals("European Cars:") || getItem(rowPosition).equals("Japanese Cars:")) {
// Make the two rows have a white background color.
row.setBackgroundColor(Color.WHITE); // this command WORKS fine by itself.
// row.setEnabled(false); this command caused "bleeding" over into other rows, so I will check for the rows in a condition.
} // both of the getItems end here.
else {
// All of the other rows should have this color.
row.setBackgroundColor(Color.parseColor("#EEE8AA"));
// the default color
} // else ends here.
//------------------------------------------
return row;
//------------------------------------------
} // getView ends here.
}); // carListview.setAdapter ends here.
} // onCreate ends here.
} // CarListActivity ends here.
Thanks, and I hope this helps others.
Hi I'm new to Android i want to create application similar to app given in this link
http://www.androiddom.com/2011/02/android-shopping-cart-tutorial.html?m=1
Only difference is that instead of list view in catalog activity I have image buttons.so wen I click any image button it goes to product details activity(same as example in link).Other activities are same as example in link.
Only thing I want is how to add item to list view by using button add to cart if there are image buttons in catalog activity.
Please do provide me help how to go about.
Main Layout File
<?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">
<ListView android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="#+id/mainListView">
</ListView>
Activity File
package com.example.android;
import java.util.ArrayList;
import java.util.Arrays;
import android.app.Activity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;
public class SimpleListViewActivity extends Activity {
private ListView mainListView ;
private ArrayAdapter<String> listAdapter ;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// Find the ListView resource.
mainListView = (ListView) findViewById( R.id.mainListView );
// Create and populate a List of context names.
String[] context = new String[] { "context1", "context2", "context3", "context4","context5"};
ArrayList<String> context = new ArrayList<String>();
contextList.addAll( Arrays.asList(context) );
// Create ArrayAdapter using the context list.
listAdapter = new ArrayAdapter<String>(this, R.layout.simplerow, contextList);
// Add more contexts. If you passed a String[] instead of a List<String>
// into the ArrayAdapter constructor, you must not add more items.
// Otherwise an exception will occur.
listAdapter.add( "context8" );
listAdapter.add( "context9" );
listAdapter.add( "context10" );
// Set the ArrayAdapter as the ListView's adapter.
mainListView.setAdapter( listAdapter );
}
}
I am having problem with the auto complete text view, when I type the drop down does not show suggestion as I type in.
What I used:
added app compact activity
created another project in android studio to see what was the problem;
I used API 2.3 and when i run the application as I type the suggestion drops down
package com.busticketing.stallionexpress;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;
public class AutoCompletetab_1 extends AppCompatActivity {
//auto complete text view
AutoCompleteTextView autoCompleteTextView;
String[] city = {"Nairobi", "Mombasa", "Lamu", "Malindi"};
//** end of auto complete text view
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.tab_1);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,android.R.layout.simple_dropdown_item_1line,city);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,android.R.layout.simple_dropdown_item_1line,city);
AutoCompleteTextView acTextView = (AutoCompleteTextView)findViewById(R.id.Android);
autoCompleteTextView.setThreshold(3);
autoCompleteTextView.setAdapter(adapter);
}
}
First of all you don't have to declare adapter two times.
You are declaring variable named as acTextView and setting adapter to autoCompleteTextView which seems undefined as your codes given above.
Give the proper id using camel case and pascal case not like Android you are giving to AutoCompleteTextView.
Your corrected code as it is
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,android.R.layout.simple_dropdown_item_1line,city);
AutoCompleteTextView acTextView = (AutoCompleteTextView)findViewById(R.id.Android);
acTextView.setThreshold(3);
acTextView.setAdapter(adapter);
I have a main activity and sliding menu beneath it I want to add a list items to the sliding menu I think my code is right but the list still not showing in the sliding section:
package com.example.example;
import java.util.ArrayList;
import java.util.Arrays;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import com.jeremyfeinstein.slidingmenu.lib.SlidingMenu;
import com.jeremyfeinstein.slidingmenu.lib.app.SlidingActivity;
public class ExampleActivity extends Activity {
private ListView mainMenu ;
private ArrayAdapter<String> listAdapter ;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// set the content view
setContentView(R.layout.activity_example);
View v = getLayoutInflater().inflate(R.layout.sliding_menu, null,true);
// setBehindContentView(v);
// Find the ListView resource.
mainMenu = (ListView) v.findViewById( R.id.exampleMenu );
// Create and populate a List of menu items names.
String[] menuText = new String[] { "Top 20", "League"};
ArrayList<String> menuList = new ArrayList<String>();
menuList.addAll( Arrays.asList(menuText) );
// Create ArrayAdapter using the menu list.
listAdapter = new ArrayAdapter<String>(this, R.layout.menu_item, menuList);
// Set the ArrayAdapter as the ListView's adapter.
mainMenu.setAdapter( listAdapter );
// configure the SlidingMenu
SlidingMenu menu = new SlidingMenu(this);
menu.setMode(SlidingMenu.LEFT);
menu.setTouchModeAbove(SlidingMenu.TOUCHMODE_FULLSCREEN);
menu.setShadowWidthRes(R.dimen.shadow_width);
menu.setShadowDrawable(R.drawable.shadow);
menu.setBehindOffsetRes(R.dimen.slidingmenu_offset);
menu.setFadeDegree(0.35f);
menu.attachToActivity(this, SlidingMenu.SLIDING_CONTENT);
menu.setMenu(R.layout.sliding_menu);
}
}
I am new to android I just want to know do I miss something here ? because the app is working but the menu is not showing . Should I add something to the code?
Edit: the setMenu as it described in the SlidingMenu.java of the sliding menu lib :
/**
* Set the behind view (menu) content from a layout resource. The resource will be inflated, adding all top-level views
* to the behind view.
*
* #param res the new content
*/
public void setMenu(int res) {
setMenu(LayoutInflater.from(getContext()).inflate(res, null));
}
/**
* Set the behind view (menu) content to the given View.
*
* #param view The desired content to display.
*/
public void setMenu(View v) {
mViewBehind.setContent(v);
}
/**
I am not familiar with Sliding menu library , but what I can see from the code is that these two lines are reason for your issue
setBehindContentView(R.layout.sliding_menu);
View v = getLayoutInflater().inflate(R.layout.sliding_menu, null);
they create two different views one goes to the actulay layout rendering and one you are creating and taking listview to set data but never added to the activity content.
I hope if you change those two lines some thing like this might work
View v = getLayoutInflater().inflate(R.layout.sliding_menu, null);
//set this v to setMenu instead of R.layout.sliding_menu
//your codes......
//
//
//menu.setMenu(R.layout.sliding_menu);
menu.setMenu(v);
I have a doubt.I have an activity which contains an autocompletetextview.The contents for autocompletetextview have been declared in strings.xml file as a string array.I hav one more string array in my strings.xml file.What i want is that when i select an item from autocompletetextview it should display a value from the second string array in the form of a toast.Is it possible.Plz help me
For Array::
String[] myarray =getResources().getStringArray(R.array.array);
For String::
String myString =getResources().getString(R.string.str);
Check with this,
package mytest.projects;
import android.app.ListActivity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
public class example extends ListActivity {
String[] mTestArray;
/** Called when the activity is first created. */
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Create an ArrayAdapter that will contain all list items
ArrayAdapter<String> adapter;
mTestArray = = getResources().getStringArray(R.array.testArray);
/* Assign the name array to that adapter and
also choose a simple layout for the list items */
adapter = new ArrayAdapter<String>(
this,
android.R.layout.simple_list_item_1,
mTestArray);
// Assign the adapter to this ListActivity
setListAdapter(adapter);
}
}