I made an array to transfer the required data consisting of 3 elements(Heading,SubHeading, int ImageResourceId).
The data shows up well in listview but I couldn't do the research inside listview.
I want to do the research using searchview on specific SubHeading or both (Heading,SubHeading)
//on creat
listView.Adapter = new HomeScreenAdapter(this, HomeScreenAdapter.tableItems);
search.QueryTextChange += SearchV_QueryTextChange;
//filter listview
private void SearchV_QueryTextChange(object sender, SearchView.QueryTextChangeEventArgs e)
{
}
//
// 3-class listview item id
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;
}
}
}
//
//class adapter & array item
class HomeScreenAdapter : BaseAdapter<TableItem>
{
public static List<TableItem> tableItems = new List<TableItem>();
List<TableItem> items;
Activity context;
public void filldata()
{
tableItems.Add(new TableItem("hussein", "devepoer", Resource.Drawable.imaga));
tableItems.Add(new TableItem("ahmed", "admin", Resource.Drawable.imagb));
tableItems.Add(new TableItem("jasim", " manager", Resource.Drawable.imagc));
tableItems.Add(new TableItem("ahmed", "admin", Resource.Drawable.imagd));
tableItems.Add(new TableItem("jasim", " manager", Resource.Drawable.image));
tableItems.Add(new TableItem("jasim", " manager", Resource.Drawable.imagf));
}
}
According to your code, I do one sample by SubHeading to filter ListView data.
Firstly, create TableItem class:
public class TableItem
{
public string Heading { get; set; }
public string SubHeading { get; set; }
public int ImageResourceId { get; set; }
}
Then creating UI for ListView item:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView android:id="#+id/textView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<TextView android:id="#+id/textView2"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<ImageView android:id="#+id/imageView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
And create Adapter and filter for data:
public class TableItemAdapter : BaseAdapter<TableItem>, IFilterable
{
private List<TableItem> _originalData;
private List<TableItem> _items;
private readonly Activity _context;
public TableItemAdapter(Activity activity, IEnumerable<TableItem> tableitems)
{
_items = tableitems.OrderBy(s => s.SubHeading).ToList();
_context = activity;
Filter = new TableItemFilter(this);
}
public override TableItem this[int position]
{
get { return _items[position]; }
}
public Filter Filter { get; private set; }
public override int Count
{
get { return _items.Count; }
}
public override long GetItemId(int position)
{
return position;
}
public override View GetView(int position, View convertView, ViewGroup parent)
{
var view = convertView ?? _context.LayoutInflater.Inflate(Resource.Layout.TableItem, null);
var tableitem = _items[position];
var HeadingView = view.FindViewById<TextView>(Resource.Id.textView1);
var SubHeadingView = view.FindViewById<TextView>(Resource.Id.textView2);
var imageView = view.FindViewById<ImageView>(Resource.Id.imageView1);
HeadingView.Text = tableitem.Heading;
SubHeadingView.Text = tableitem.SubHeading;
imageView.SetImageResource(tableitem.ImageResourceId);
return view;
}
public override void NotifyDataSetChanged()
{
// If you are using cool stuff like sections
// remember to update the indices here!
base.NotifyDataSetChanged();
}
private class TableItemFilter : Filter
{
private readonly TableItemAdapter _adapter;
public TableItemFilter(TableItemAdapter adapter)
{
_adapter = adapter;
}
protected override FilterResults PerformFiltering(ICharSequence constraint)
{
var returnObj = new FilterResults();
var results = new List<TableItem>();
if (_adapter._originalData == null)
_adapter._originalData = _adapter._items;
if (constraint == null) return returnObj;
if (_adapter._originalData != null && _adapter._originalData.Any())
{
// Compare constraint to all names lowercased.
// It they are contained they are added to results.
results.AddRange(
_adapter._originalData.Where(
item => item.SubHeading.ToLower().Contains(constraint.ToString())));
}
// Nasty piece of .NET to Java wrapping, be careful with this!
returnObj.Values = FromArray(results.Select(r => r.ToJavaObject()).ToArray());
returnObj.Count = results.Count;
constraint.Dispose();
return returnObj;
}
protected override void PublishResults(ICharSequence constraint, FilterResults results)
{
using (var values = results.Values)
_adapter._items = values.ToArray<Java.Lang.Object>().Select(r =>r.ToNetObject<TableItem>()).ToList();
_adapter.NotifyDataSetChanged();
// Don't do this and see GREF counts rising
constraint.Dispose();
results.Dispose();
}
}
}
ObjectExtensions to implement filter:
public class JavaHolder : Java.Lang.Object
{
public readonly object Instance;
public JavaHolder(object instance)
{
Instance = instance;
}
}
public static class ObjectExtensions
{
public static TObject ToNetObject<TObject>(this Java.Lang.Object value)
{
if (value == null)
return default(TObject);
if (!(value is JavaHolder))
throw new InvalidOperationException("Unable to convert to .NET object. Only Java.Lang.Object created with .ToJavaObject() can be converted.");
TObject returnVal;
try { returnVal = (TObject)((JavaHolder)value).Instance; }
finally { value.Dispose(); }
return returnVal;
}
public static Java.Lang.Object ToJavaObject<TObject>(this TObject value)
{
if (Equals(value, default(TObject)) && !typeof(TObject).IsValueType)
return null;
var holder = new JavaHolder(value);
return holder;
}
}
Mainactivity.cs:
public class MainActivity : AppCompatActivity
{
private SearchView searchview1;
private ListView listview1;
private TableItemAdapter tableitemadapter;
private List<TableItem> tableitems;
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
Xamarin.Essentials.Platform.Init(this, savedInstanceState);
// Set our view from the "main" layout resource
SetContentView(Resource.Layout.activity_main);
searchview1 = FindViewById<SearchView>(Resource.Id.searchView1);
listview1 = FindViewById<ListView>(Resource.Id.listView1);
tableitems = new List<TableItem>()
{
new TableItem(){Heading= "hussein", SubHeading="devepoer",ImageResourceId= Resource.Drawable.plu3 },
new TableItem(){Heading= "ahmed", SubHeading="admin",ImageResourceId= Resource.Drawable.plu3 },
new TableItem(){Heading= "jasim", SubHeading="manager",ImageResourceId= Resource.Drawable.plu3 },
new TableItem(){Heading= "cherry", SubHeading="admin",ImageResourceId= Resource.Drawable.plu3 },
new TableItem(){Heading= "barry", SubHeading="manager",ImageResourceId= Resource.Drawable.plu3 },
new TableItem(){Heading= "annine", SubHeading="manager",ImageResourceId= Resource.Drawable.plu3 }
};
tableitemadapter = new TableItemAdapter(this,tableitems);
listview1.Adapter = tableitemadapter;
searchview1.QueryTextChange += Searchview1_QueryTextChange;
}
private void Searchview1_QueryTextChange(object sender, SearchView.QueryTextChangeEventArgs e)
{
tableitemadapter.Filter.InvokeFilter(e.NewText);
}
public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Android.Content.PM.Permission[] grantResults)
{
Xamarin.Essentials.Platform.OnRequestPermissionsResult(requestCode, permissions, grantResults);
base.OnRequestPermissionsResult(requestCode, permissions, grantResults);
}
}
The sample in github:
https://github.com/CherryBu/Searchviewsample
The screenshot:
I am new to MvvmCross, I have a question with regards to binding in Android. I can bind to single property but unable to data bind to an object. Not sure what I am doing wrong but here it is:
Model class:
public class Login : MvxNotifyPropertyChanged
{
private string _email;
public string Email
{
get { return _email; }
set
{
SetProperty(ref _email, value);
}
}
public string Password { get; set; }
}
Snippet of View Model Class:
public class LoginOptionViewModel: MvxViewModel
{
private readonly IMvxNavigationService _navigationService;
public LoginOptionViewModel(IMvxNavigationService navigationService)
{
_navigationService = navigationService;
LoginCommand =
new MvxAsyncCommand(async () => await _navigationService.Navigate<RegistrationViewModel>());
}
public IMvxAsyncCommand LoginCommand { get; set; }
private Login _loginInfo;
public Login LoginInfo
{
get
{
return _loginInfo ?? new Login();
}
set
{
_loginInfo = value;
RaisePropertyChanged(() => LoginInfo);
}
}
}
Snippet of Android Axml:
<EditText
android:id="#+id/loginEmailTxt"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="#string/EmailHint"
android:textColor="#color/darkNavy"
android:inputType="textEmailAddress"
local:MvxBind="Text LoginInfo.Email" />
Where am I going wrong, I have placed a breakpoint but do not see it being hit. This is binded to EditText but nothing appears to happen. Am I missing or doing something wrong in order to bind to an object property ?
MvvmCross object data binding
You could implement the MvxNotifyPropertyChanged interface, so the system could notifies clients that a property value has changed.
Modify your object to :
public class Login : MvxNotifyPropertyChanged
{
private string _email;
public string Email
{
get => _email;
set => SetProperty(ref _email, value);
}
}
In the MainViewModel :
private Login _login;
public Login Login
{
get
{
return _login ?? new Login() { Email = "=-="};
}
set
{
_login = value;
RaisePropertyChanged(() => Login);
}
}
Then use it in axml :
local:MvxBind="Text Login.Email"
It works fine on my side.
Update :
I cant reproduce your problem, but here is my complete code, hope this can help you :
public class MainViewModel : MvxViewModel
{
public MainViewModel()
{
}
public override Task Initialize()
{
return base.Initialize();
}
public IMvxCommand ResetTextCommand => new MvxCommand(ResetText);
private void ResetText()
{
Text = "Hello MvvmCross";
}
private string _text = "Hello MvvmCross";
public string Text
{
get { return _text; }
set { SetProperty(ref _text, value); }
}
private Login _login;
public Login Login
{
get
{
return _login ?? new Login() { Email = "=-="};
}
set
{
_login = value;
RaisePropertyChanged(() => Login);
}
}
}
public class Login : MvxNotifyPropertyChanged
{
private string _email;
public string Email
{
get => _email;
set => SetProperty(ref _email, value);
}
}
Effect.
In my example below I want to bind an ItemClick Command to the Item in the MvxListView.
Here I have in my ViewModel a List of Person that contains a List of Dog.
The ItemsSource HasDogs binding works fine.
When MvvmCross is trying to bind ItemClick SelectDogCommand to the ICommand in the Viewmodel I get this Exception.
[0:]
MvxBind:Warning: 11,30 Unable to bind: source property source not found Property:SelectDogCommand on Person
[0:] MvxBind:Warning: 11,30 Unable to bind: source property source not found Property:SelectDogCommand on Person
12-04 15:05:03.062 I/mono-stdout(16338): MvxBind:Warning: 11,30 Unable to bind: source property source not found Property:SelectDogCommand on Person
Hope you can Help.
Here is my example:
public class FirstViewModel:MvxViewModel
{
private List<Person> _persons;
public List<Person> Persons
{
get { return _persons; }
set { _persons = value; }
}
private Cirrious.MvvmCross.ViewModels.MvxCommand<Dog> _selectDog;
public System.Windows.Input.ICommand SelectDogCommand
{
get
{
_selectDog = _selectDog ?? new Cirrious.MvvmCross.ViewModels.MvxCommand<Dog>(SelectDog);
return _selectDog;
}
}
private void SelectDog(Dog item)
{
ShowViewModel<DetailViewModel>(new DetailViewModel.Parameters{dog = item});
}
}
public class Person
{
private string _name;
private List<Dog> _hasDogs;
public List<Dog> HasDogs
{
get { return _hasDogs; }
set { _hasDogs = value; }
}
public string Name
{
get { return _name; }
set { _name = value; }
}
}
public class Dog{...}
The Android View Xml:
FirstView:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:local="http://schemas.android.com/apk/res-auto"
...>
<TextView ...
local:MvxBind="Text Persons"
<Mvx.MvxListView
...
local:MvxBind="ItemsSource Persons"
local:MvxItemTemplate="#layout/item_person" />
</LinearLayout>
item_person:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:local="http://schemas.android.com/apk/res-auto"
...
android:layout_height="200dp">
<TextView
...
local:MvxBind="Text Name" />
<Mvx.MvxListView
...
local:MvxBind="ItemsSource HasDogs; ItemClick SelectDogCommand"
local:MvxItemTemplate="#layout/item_dog" />
</LinearLayout>
The DataContext for your person list item is a Person - so your SelectDogCommand needs to be part of the Person class - e.g. something like:
public class Person
{
private string _name;
private List<Dog> _hasDogs;
public List<Dog> HasDogs
{
get { return _hasDogs; }
set { _hasDogs = value; }
}
public string Name
{
get { return _name; }
set { _name = value; }
}
private Cirrious.MvvmCross.ViewModels.MvxCommand<Dog> _selectDog;
public System.Windows.Input.ICommand SelectDogCommand
{
get
{
_selectDog = _selectDog ?? new Cirrious.MvvmCross.ViewModels.MvxCommand<Dog>(dog => _parent.SelectDog(dog));
return _selectDog;
}
}
private FirstViewModel _parent;
public Person(FirstViewModel parent)
{
_parent = parent;
}
}
or alternatively you could get Person to inherit from MvxNavigatingObject (or MvxPropertyChanged or MvxViewModel) - in which case the ShowViewModel methods will be available there too.
The AXML:
<Button
android:id="#+id/greenButton"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Green"
local:MvxBind="Click ShowColorCommand, CommandParameter='Green'"/>
and the ViewModel:
public class MainViewModel
: MvxViewModel
{
public ICommand ShowColorCommand
{
get
{
return new MvxCommand(() => ShowViewModel<ColorViewModel>(new { color = ??? } ));
}
}
}
How do I read/use the CommandParameter from the .axml ('Green') in my Command? What do I need to put inside the "???"
Any help appreciated
Use the generic MvxCommand<T> form - there's a string example in Using MvxCommand With CommandParameter binding
new MvxCommand<string>(param =>
{
if (param == "foo")
{
// do something
}
else if (param == "bar")
{
// do something else
}
});
In a WPF treeview I am trying to automatically check the children if the parent node is being checked. I am using a view model for that and a bindable object for the nodes, however all my attempts failed. Here is the code (C# + XAML). Any ideas would be greatly appreciated
<Window x:Class="TestCheckBoxBinding.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:TestCheckBoxBinding"
Title="Window1" Height="300" Width="300">
<Window.Resources>
<Style TargetType="{x:Type TreeViewItem}">
<Setter Property="IsExpanded" Value="True"/>
</Style>
<HierarchicalDataTemplate DataType="{x:Type local:TestCategory}" ItemsSource="{Binding Tests, Mode=OneTime}">
<Label Content="{Binding Name}"></Label>
</HierarchicalDataTemplate>
<HierarchicalDataTemplate DataType="{x:Type local:Test}" ItemsSource="{Binding Children, Mode=OneTime}">
<StackPanel Orientation="Horizontal">
<CheckBox VerticalAlignment="Center" IsChecked="{Binding IsChecked, Mode=TwoWay}"></CheckBox>
<Label Content="{Binding Name}"></Label>
</StackPanel>
</HierarchicalDataTemplate>
</Window.Resources>
<Grid>
<TreeView ItemsSource="{Binding Categories, Mode=OneTime}"></TreeView>
</Grid>
public class TestsViewModel
{
public static void PopulateList(TestsViewModel vm)
{
TestCategory cat1 = new TestCategory() { Id = 1, Name = "First category" };
Test t1 = new Test() { Name = "Test1" };
Test t2 = new Test() { Name = "Test2" };
Test t3 = new Test() { Name = "Test3" };
t1.AddChild(t2);
t1.AddChild(t3);
Test t4 = new Test() { Name = "Test4" };
cat1.AddTest(t1);
cat1.AddTest(t4);
vm.AddTestCategory(cat1);
TestCategory cat2 = new TestCategory() { Id = 2, Name = "Second category" };
Test t5 = new Test() { Name = "Test1" };
Test t6 = new Test() { Name = "Test2" };
Test t7 = new Test() { Name = "Test3" };
t6.AddChild(t7);
Test t8 = new Test() { Name = "Test4" };
cat2.AddTest(t5);
cat2.AddTest(t6);
cat2.AddTest(t8);
vm.AddTestCategory(cat2);
}
private readonly IEnumerable<TestCategory> categories = new List<TestCategory>();
public IEnumerable<TestCategory> Categories { get { return categories; } }
public void AddTestCategory(TestCategory testCategory)
{
((IList<TestCategory>)categories).Add(testCategory);
}
}
public class TestCategory
{
public int Id { get; set; }
public string Name { get; set; }
private readonly IEnumerable<Test> tests = new List<Test>();
public IEnumerable<Test> Tests { get { return tests; } }
public void AddTest(Test t)
{
((IList<Test>)tests).Add(t);
}
}
public class Test : INotifyPropertyChanged
{
private string name;
public string Name
{
set
{
if (name != value)
{
name = value;
this.OnPropertyChanged("Name");
}
}
get { return name; }
}
public bool? isChecked = false;
public bool? IsChecked
{
get { return isChecked; }
set
{
if (isChecked != value)
{
isChecked = value;
if (children.Count() > 0)
{
foreach (var test in children)
{
test.isChecked = value;
test.Name += ".";
}
}
this.OnPropertyChanged("IsChecked");
}
}
}
public void AddChild(Test test)
{
((IList<Test>)children).Add(test);
}
private readonly IEnumerable<Test> children = new List<Test>();
public IEnumerable<Test> Children
{
get { return children; }
}
#region INotifyPropertyChanged Members
// Create the OnPropertyChanged method to raise the event
protected void OnPropertyChanged(string propName)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(propName));
}
}
public event PropertyChangedEventHandler PropertyChanged;
#endregion
}
Oups, child checkboxes are not being checked because I wasn't setting their IsChecked property. I was setting the isChecked field, which bypasses the property setter and prevents PropertyChanged from being raised.