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Android - Check checkbox in 'Custom ListView' using Boolean

I have a custom listview in my C# Android app, each row contains a textview, ImageView and a checkbox. When a Listview item is clicked, I want to check the row's item checkbox using bool value.
MainActivity.cs
List<TableList> list = = new List<TableList>();
list.Add(new TableList("Germany"));
list.Add(new TableList("France"));
list.Add(new TableList("Finland"));
listView.ItemClick += delegate (object sender, AdapterView.ItemClickEventArgs e)
{
string selected = t.Name;
if (selected == "France")
{
Class1.bl = false; // Check the proper checkbox for France row
}
};
Class1.bl is a static public bool set to true
ListAdapter and ListClass for the Listview:
public class ListAdapter : BaseAdapter<TableList>
{
List<TableList> items;
Activity context;
public ListAdapter(Activity context, List<TableList> items)
: base()
{
this.context = context;
this.items = items;
}
public override long GetItemId(int position)
{
return position;
}
public override TableList this[int position]
{
get { return items[position]; }
}
public override int Count
{
get { return items.Count; }
}
public override View GetView(int position, View convertView, ViewGroup parent)
{
var item = items[position];
View view = convertView;
if (view == null) // no view to re-use, create new
view = context.LayoutInflater.Inflate(Resource.Layout.CoinList, null);
view.FindViewById<TextView>(Resource.Id.CoinName).Text = item.Name;
view.FindViewById<ImageView>(Resource.Id.imageView1).SetImageResource(Resource.Drawable.n);
if (Class1.bl == false)
{
view.FindViewById<CheckBox>(Resource.Id.checkBox1).Checked = true;
Class1.bl = true;
}
else
{
view.FindViewById<CheckBox>(Resource.Id.checkBox1).Checked = false;
}
return view;
}
}
public class TableList
{
public string Name;
public TableList(string Name)
{
this.Name = Name;
}
}
The above code when I run it, and I select France, the ChechBox is checked for France but when I check another item like Germany, the ChechBox for Germany is not checked. Why is this and how can I solve it ?

I have add the bool in your TableList class:
//I add the bool in this class, so you can change the CheckBox's state by your Data Source
//That means that your CheckBox's state based upon your Data Source.
public class TableList : Java.Lang.Object
{
public TableList(string name, bool b)
{
this.Name = name;
this.bl = b;
}
public string Name { get; set; }
public bool bl { get; set; }
}
I also provide the demo on the github, and here is the result gif.

how to populate date from webservice to xamarin android

I can't populate date from webservice to xamarin android
namespace Printopack
{
[Activity(Label = "Mainlistview", Icon = "#drawable/icon")]
public class Mainlistview : Activity
{
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
SetContentView(Resource.Layout.Mainlistview);
ListView ListView = FindViewById<ListView>(Resource.Id.listView1);
Selling.WebServiceDB ws = new Selling.WebServiceDB();
ws.OrderStatusListCompleted += Ws_OrderStatusListCompleted;
ws.OrderStatusListAsync(Convert.ToString(1));
}
private void Ws_OrderStatusListCompleted(object sender, Selling.OrderStatusListCompletedEventArgs e)
{
ListView ListView = FindViewById<ListView>(Resource.Id.listView1);
string msg = "";
if (e.Result.ToString().Equals("0"))
{
msg = e.Result.ToString();
}
else
{
// full class
List<TableItem> tableItems = new List<TableItem>();
tableItems.Add(new TableItem("" + e.Result, "" + e.Result, Resource.Drawable.Icon));
ListView.Adapter = new HomeScreenAdapter(this, tableItems);
}
}
// adpater manage
public class HomeScreenAdapter : BaseAdapter<TableItem>
{
List<TableItem> items;
Activity context;
public HomeScreenAdapter(Activity context, List<TableItem> items)
: base()
{
this.context = context;
this.items = items;
}
public override long GetItemId(int position)
{
return position;
}
public override TableItem this[int position]
{
get { return items[position]; }
}
public override int Count
{
get { return items.Count; }
}
public override View GetView(int position, View convertView, ViewGroup parent)
{
var item = items[position];
View view = convertView;
if (view == null) // no view to re-use, create new
view = context.LayoutInflater.Inflate(Resource.Layout.Ticket_News, null);
view.FindViewById<TextView>(Resource.Id.Text1).Text = item.Heading;
view.FindViewById<TextView>(Resource.Id.Text2).Text = item.SubHeading;
view.FindViewById<ImageView>(Resource.Id.Image).SetImageResource(item.ImageResourceId);
return view;
}
}
public class TableItem
{
public string Heading;
public string SubHeading;
public int ImageResourceId;
public TableItem(string Heading, string SubHeading, int ImageResourceId)
{
this.Heading = Heading;
this.SubHeading = SubHeading;
this.ImageResourceId = ImageResourceId;
}
}
}
}

I think the error is in this line:
tableItems.Add(new TableItem("" + e.Result, "" + e.Result, Resource.Drawable.Icon));
You're adding the e.Result as one item and I think the Result holds the complete list. You should loop through the entries in the e.Result and call tableItems.Add for each of them.
Similar to this:
foreach (var item in e.Result)
{
tableItems.Add(new TableItem("" + item.Property, "" + item.Property1, Resource.Drawable.Icon));
}

Android.App.Activity is a type but a variable was expected

string[] arrays = new string[] { "A", "B", "C", "D", "E", "F" };
ListView lstItems;
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
// Set our view from the "main" layout resource
SetContentView(Resource.Layout.Main);
// Get our button from the layout resource,
// and attach an event to it
lstItems = FindViewById<ListView>(Resource.Id.listView1);
lstItems.Adapter = new CustomAdapter(Activity, arrays);
}
public class CustomAdapter : BaseAdapter
{
//private const int TYPE_ITEM = 0;
//private const int TYPE_SEPARATOR = 1;
string[] mData;
//private TreeSet sectionHeader;
LayoutInflater mInflater;
public CustomAdapter(Context context, string[] Data)
{
mInflater = LayoutInflater.FromContext(context);
mData = Data;
}
public override int Count
{
get { return mData.Length; }
}
public override Java.Lang.Object GetItem(int position)
{
return mData[position];
}
public override long GetItemId(int position)
{
return position;
}
public override View GetView(int position, View convertView, ViewGroup parent)
{
ViewHolder holder = null;
//var data = mData [position];
if (convertView == null)
{
holder = new ViewHolder();
holder.textViewHeader = (TextView)convertView.FindViewById(Resource.Id.textviewHeaderItems);
holder.textViewSeparator = (TextView)convertView.FindViewById(Resource.Id.textviewItemsSeparator);
convertView.Tag = holder;
}
else
{
holder = (ViewHolder)convertView.Tag as ViewHolder;
}
for (int i = 0; i <= mData.Length - 1; i++)
{
if (i == 0)
{
holder.textViewHeader.Text = "Group A";
}
else if (i == 4)
{
holder.textViewHeader.Text = "Group B";
}
holder.textViewSeparator.Text = mData[i];
}
return convertView;
}
}
public class ViewHolder : Java.Lang.Object
{
public TextView textViewHeader { get; set; }
public TextView textViewSeparator { get; set; }
}
In CustomerAdapter I have a string[] Data parameter. After in OnCreate I got this problem at lstItems.Adapter = new CustomAdapter(Activity, arrays). I don't understand.
I was trying to create a header listview on xamarin android.
I saw several samples but that code has much errors.

You are passing the Activity class name. Instead you should pass an instance of the Activity you are in. You should be instantiating Adapter like below from Activity
lstItems.Adapter = new CustomAdapter (this, arrays);

Activity is a type. What you need is an instance of type Context. In Xamarin Android that's most commonly Android.App.Application.Context.
So your line should look like this:
lstItems.Adapter = new CustomAdapter(Android.App.Application.Context, arrays);

Xamarin passing context from OnClick event

I m a beginner in android dev, I m struggling with passing string Clicked_Message from Click event in Recycle Adapter Class to the other activity. Is it a good way to use Intent? If so how can I pass context to click event? Thanks
public class RecyclerAdapter : RecyclerView.Adapter
{
private RecyclerView mRecyclerView;
private List<NotificationClass> mEmails;
public RecyclerAdapter(List<NotificationClass> emails, RecyclerView recyclerView)
{
mEmails = emails;
mRecyclerView = recyclerView;
}
public class MyView : RecyclerView.ViewHolder
{
public View mMainView { get; set; }
public TextView mName { get; set; }
public TextView mSubject { get; set; }
public TextView mMessage { get; set; }
public MyView(View view) : base(view)
{
mMainView = view;
}
}
public override RecyclerView.ViewHolder OnCreateViewHolder(ViewGroup parent, int viewType)
{
View row = LayoutInflater.From(parent.Context).Inflate(Resource.Layout.row, parent, false);
TextView txtName = row.FindViewById<TextView>(Resource.Id.txtName);
TextView txtSubject = row.FindViewById<TextView>(Resource.Id.txtSubject);
TextView txtMessage = row.FindViewById<TextView>(Resource.Id.txtMessage);
MyView view = new MyView(row) { mName = txtName, mSubject = txtSubject, mMessage = txtMessage };
return view;
}
public override void OnBindViewHolder(RecyclerView.ViewHolder holder, int position)
{
MyView myHolder = holder as MyView;
int indexPosition = (mEmails.Count - 1) - position;
myHolder.mMainView.Click += mMainView_Click;
myHolder.mName.Text = mEmails[position].Name;
myHolder.mSubject.Text = mEmails[position].Subject;
myHolder.mMessage.Text = mEmails[position].Message;
}
public override int ItemCount
{
get { return mEmails.Count; }
}
public void OnClick(int position)
{
if (ItemClick != null)
ItemClick(this, position);
}
public void mMainView_Click(object sender, EventArgs e,Context context)
{
int position = mRecyclerView.GetChildPosition((View)sender);
int indexPosition = (mEmails.Count - 1) - position;
Console.WriteLine(mEmails[indexPosition].Message);
string Clicked_Message = (mEmails[indexPosition].Message);
var activity2 = new Intent(context, typeof(ContactActivity));
activity2.PutExtra("MyData", Clicked_Message);
context.StartActivity(activity2);
}
}

You don't need to pass a context. Just use an intent and put the information you want to pass as extras into the intent.
In case your adapter needs a context, pass it in through the constructor and store it as a field member.

This is my typical implementation of the RecyclerView.Adapter with a view holder...
public class ContactsAdapter : V7.RecyclerView.Adapter
{
private List<Contact> _contacts;
public event EventHandler ItemClick;
public void OnItemClick(ContactViewHolder holder)
{
if (ItemClick != null)
{
ItemClick(holder, EventArgs.Empty);
}
}
public ContactsAdapter(List<Contact> contacts)
: base()
{
_contacts = contacts;
}
public override void OnBindViewHolder(V7.RecyclerView.ViewHolder holder, int position)
{
var contactHolder = (ContactViewHolder)holder;
contactHolder.BindUI(_contacts[position]);
}
public override V7.RecyclerView.ViewHolder OnCreateViewHolder(ViewGroup parent, int viewType)
{
var view = LayoutInflater.FromContext(parent.Context).Inflate(Resource.Layout.ContactsListItem, parent, false);
return new ContactViewHolder(view)
{
Adapter = this
};
}
public override int ItemCount
{
get
{
return _contacts.Count;
}
}
}
View Holder (typically in the same file as the adapter)
public class ContactViewHolder : V7.RecyclerView.ViewHolder, View.IOnClickListener
{
public TextView ContactNameTextView { get; set; }
public TextView ContactPhoneTextView { get; set; }
public TextView ContactIntialsTextView { get; set; }
public Contact Contact { get; set; }
private WeakReference _adapter;
public ContactsAdapter Adapter
{
get { return (ContactsAdapter)_adapter.Target; }
set { _adapter = new WeakReference(value); }
}
public ContactViewHolder(View view)
: base(view)
{
GetUI(view);
view.SetOnClickListener(this);
}
private void GetUI(View view)
{
ContactNameTextView = view.FindViewById<TextView>(Resource.Id.ContactName);
ContactPhoneTextView = view.FindViewById<TextView>(Resource.Id.ContactPhone);
ContactIntialsTextView = view.FindViewById<TextView>(Resource.Id.ContactInitialsTextView);
}
public void BindUI(Contact contact)
{
Contact = contact;
ContactNameTextView.Text = contact.ContactName;
ContactPhoneTextView.Text = contact.Phone1;
ContactIntialsTextView.Text = contact.Initials;
}
public void OnClick(View v)
{
Adapter.OnItemClick(this);
}
}
This encapsulates the functionality to the view holder. I also give the instance of the adapter to the view holder as a WeakReference. This allows me to call the OnItemClick, passing the instance of the view holder. If you will notice that the view holder also has an instance of the object that it is representing. This means I don't have to worry about the index that was chosen. I already have the object data available to me.
So the implementation in the Activity/Fragment is like this...
public override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
_contacts = Contact.GetAllContacts();
_adapter = new ContactsAdapter(_contacts);
_adapter.ItemClick += ContactSelected;
}
public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
var view = inflater.Inflate(Resource.Layout.ContactsFragment, container, false);
var layoutManager = new V7.LinearLayoutManager(this.Activity) { Orientation = V7.LinearLayoutManager.Vertical };
_contactsView = view.FindViewById<V7.RecyclerView>(Resource.Id.ContactList);
_contactsView.SetAdapter(_adapter);
_contactsView.HasFixedSize = true;
_contactsView.SetLayoutManager(layoutManager);
return view;
}
private void ContactSelected (object sender, EventArgs e)
{
var holder = (ContactViewHolder)sender;
var detailFragment = new ContactDetailsFragment(holder.Contact);
MainActivity.ShowFragment(detailFragment);
}
I give the Contact to a Fragment, but you could do something similar for an activity using an intent.
Now whether this is the most efficient way of handling a click of a row in a RecyclerView, I don't know. But this implementation has been working for me.

How can I update propertygrid item values when another item changed in winform c#?

I have a property grid with 2 items. Country & Cities. I have 1 table in database : CountryCityTable that save LocationId, Title , ParentId. For countries parentId = 0 and for cities is countryid.
In my propertygrid, I use these and show in 2 combobox items. Please see my code :
namespace ProGrid
{
public class KeywordProperties
{
[TypeConverter(typeof(CountryLocationConvertor))]
public string CountryNames { get; set; }
[TypeConverter(typeof(CityLocationConvertor))]
public string CityNames { get; set; }
}
}
And
namespace ProGrid
{
public class CountryLocationConvertor : StringConverter
{
public override bool GetStandardValuesSupported(ITypeDescriptorContext context)
{
return true;
}
public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext context)
{
HumanRoles Db = new HumanRoles();
List<LocationsFieldSet> Items = new List<LocationsFieldSet>();
Items = Db.LoadLocations(0,0);
string[] LocationItems = new string[Items.Count];
int count = 0;
foreach (LocationsFieldSet Item in Items)
{
LocationItems[count] = Item.Title;
count++;
}
return new StandardValuesCollection(LocationItems);
}
public override bool GetStandardValuesExclusive(ITypeDescriptorContext context)
{
return true;//false : If you want the user to be able to type in a value that is not in the drop-down list.
}
}
public class CityLocationConvertor : StringConverter
{
public override bool GetStandardValuesSupported(ITypeDescriptorContext context)
{
return true;
}
public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext context)
{
HumanRoles Db = new HumanRoles();
List<LocationsFieldSet> Items = new List<LocationsFieldSet>();
Items = Db.LoadLocations(1,20);
string[] LocationItems = new string[Items.Count];
int count = 0;
foreach (LocationsFieldSet Item in Items)
{
LocationItems[count] = Item.Title;
count++;
}
return new StandardValuesCollection(LocationItems);
}
public override bool GetStandardValuesExclusive(ITypeDescriptorContext context)
{
return true;
}
}
}
And
KeywordProperties Kp = new KeywordProperties();
myPropertyGrid.SelectedObject = Kp;
Now, I want when user changed country title in propertygrid, List of cities updated(just display cities that parentid of these = countryid).
Also, in my class how can i change Number 20 in my code(Db.LoadLocations(1,20);) to selected country id ?
Thank's.

You will need to implement something similar to INotifyPropertyChanged
Microsoft INotifyPropertyChange Documentation
In other word, you will need to have some event raised when you chance one property. As far as I remember, the property grid automaticly check for that type of event/interface and refresh the correct property node when the event is raised.
The important part is:
private void NotifyPropertyChanged([CallerMemberName] String propertyName = "")
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
and
public bool MyBoolProperty
{
get { return myBoolField; }
set
{
myBoolField = value;
NotifyPropertyChanged();
}
}
If you want to do something that is not covered by the PropertyGrid, you simply need to register your own method in the PropertyChanged event and do whatever you please.