Validating Listbox MVVM - c#

I am using Caliburn.Micro to do convention based binding of the contents of my listbox from a BindableCollection in my ViewModel.
I want to perform Validation on it so that when there is no selection and the user exits the form they get that nice red line around the listbox with the error message that they have to select a value. So far Caliburn has worked great for textbox validation but I can't seem to get it to work on the listbox!
On a side note, is there any way to forcibly run a complete validation from the VM? Currently I am merely doing manual validation by checking the values and changing them so it triggers the Validator which is a bit backwards..
Here is the code for my view:
<UserControl x:Class="AddSessionDialogView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:toolkit="http://schemas.microsoft.com/winfx/2006/xaml/presentation/toolkit">
<toolkit:BusyIndicator IsBusy="{Binding IsBusy}" BusyContent="{Binding IsBusyStatusDisplay}">
<Grid x:Name="LayoutRoot" Background="White">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="100" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="auto"/>
<RowDefinition Height="*"/>
<RowDefinition Height="auto" />
<RowDefinition Height="auto"/>
</Grid.RowDefinitions>
<Grid.Resources>
<Style TargetType="TextBlock">
<Setter Property="Margin" Value="5,9" />
</Style>
<Style TargetType="TextBox">
<Setter Property="Margin" Value="5" />
</Style>
</Grid.Resources>
<TextBlock Text="Session Name" />
<TextBox x:Name="SessionName" Grid.Column="1" />
<TextBlock Text="Scenario" Grid.Row="1" />
<ListBox x:Name="Scenarios" Grid.Row="1" Grid.Column="1" DisplayMemberPath="Name" Margin="5" />
<StackPanel Orientation="Horizontal" HorizontalAlignment="Right" VerticalAlignment="Bottom" Grid.Column="1" Grid.Row="3" Margin="5">
<Button x:Name="Cancel" Height="28" Margin="5" Content="Cancel" Padding="0,2" Width="75" />
<Button x:Name="OK" Height="28" Margin="5" Content="OK" Padding="0,2" Width="100" />
</StackPanel>
</Grid>
</toolkit:BusyIndicator>
Here is the (relevant) code for my viewmodel:
public BindableCollection<Scenario> Scenarios { get; set; }
[Required(ErrorMessage = "You must select a scenario")]
public Scenario SelectedScenario { get; set; }
private string _sessionName;
[Required(ErrorMessage="Session Name is invalid")]
public string SessionName
{
get { return _sessionName; }
set { _sessionName = value; NotifyOfPropertyChange(() => SessionName); }
}
public IEnumerable<IResult> OK()
{
if (SelectedScenario == null)
{
// This forces validation check, but doesnt show validation error on the view!
SelectedScenario = new Scenario();
SelectedScenario = null;
}
if (SessionName == null)
SessionName = "";
if (Validator.TryValidateObject(this, new ValidationContext(this), new List<ValidationResult>()))
{
IsBusy = true;
IsBusyStatusDisplay = "Creating Session...";
yield return new CreateSessionResult(SelectedScenario.Id, SessionName);
IsBusy = false;
yield return Close();
}
}

Related

How can I hide rows in a DataGrid?

I am trying to create a "notes" app using wpf mvvm. I have a MainWindow containing a DataGrid with data that is bound to an ObservableCollection. In MainWindowView I have a "Find" button which calls FindWindowDialog. In the FindWindowDialog in the textbox, I must enter the text that will be searched and click "Find", after which the DataGrid MainWindowView should hide those lines whose content does not contain the searched text. I don't really know how to do this, after 2 days of searching I decided to ask a question. I googled on this topic and I have a suggestion that I should delve into the messenger pattern and converters
MainWindow.xaml(View)
<Window x:Class="NotesARK6.View.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:NotesARK6.View"
xmlns:model="clr-namespace:NotesARK6.Model"
xmlns:viewmodel="clr-namespace:NotesARK6.ViewModel"
mc:Ignorable="d"
Title="Notes" Height="450" Width="800"
x:Name="_mainWindow"
WindowStartupLocation="CenterScreen">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="20" />
<ColumnDefinition Width="*" />
<ColumnDefinition Width="20" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="20"/>
<RowDefinition Height="1*"/>
<RowDefinition Height="10*"/>
<RowDefinition Height="20"/>
</Grid.RowDefinitions>
<DataGrid ItemsSource="{Binding NotesCollection}" SelectedItem="{Binding SelectedNote}" IsReadOnly="True" AutoGenerateColumns="False" x:Name="DataGrid_Notes" Margin="5" Grid.Row="2" Grid.Column="1">
<DataGrid.InputBindings>
<MouseBinding Gesture="LeftDoubleClick" Command="{Binding EditNoteCommand}" CommandParameter="{Binding SelectedNote}" />
</DataGrid.InputBindings>
<DataGrid.Columns>
<DataGridTextColumn Header="Name" Width="1*" Binding="{Binding Name}"/>
<DataGridTextColumn Header="Content" Width="3*" Binding="{Binding Content}"/>
</DataGrid.Columns>
</DataGrid>
<ToolBar Grid.Row="1" Grid.Column="1" Margin="5">
<Button Content="Create" Command="{Binding CreateNewNoteCommand}"/>
<Separator />
<Button Content="Delete" Command="{Binding DeleteNoteCommand}" CommandParameter="{Binding SelectedNote}"/>
<Separator />
<Button Content="Find" Command="{Binding FindNoteCommand}"/>
</ToolBar>
</Grid>
</Window>
FindWindowDialog.xaml(view)
<Window x:Class="NotesARK6.ViewModel.Dialogs.FindWindowDialog"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:NotesARK6.ViewModel.Dialogs"
mc:Ignorable="d"
Title="Find" Height="250" Width="400"
WindowStartupLocation="CenterScreen"
Topmost="True">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="20"/>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="20"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="40"/>
<RowDefinition Height="35"/>
<RowDefinition Height="60"/>
<RowDefinition Height="50"/>
<RowDefinition Height="90"/>
</Grid.RowDefinitions>
<Grid Grid.Row="1" Grid.Column="1">
<Grid.ColumnDefinitions>
<ColumnDefinition />
<ColumnDefinition />
</Grid.ColumnDefinitions>
<CheckBox IsChecked="{Binding SearchByName}" VerticalAlignment="Center" HorizontalAlignment="Center" Margin="5" Content="Search by name" Grid.Column="0"></CheckBox>
<CheckBox IsChecked="{Binding SearchByContent}" VerticalAlignment="Center" HorizontalAlignment="Center" Margin="5" Content="Search by content" Grid.Column="1"></CheckBox>
</Grid>
<TextBox Text="{Binding SearchString}" Margin="5" Grid.Row="2" Grid.Column="1"/>
<Button Command="{Binding FindNotesCommand}" Margin="5" Content="Find" Grid.Row="3" Grid.Column="1" />
</Grid>
</Window>
FindWindowDialogViewModel.cs
public class FindWindowDialogViewModel : INotifyPropertyChanged
{
private string searchString;
private bool searchByName;
private bool searchByContent;
//Controll Commands
public ControllComands FindNotesCommand { get; private set; }
//Controll Commands
public FindWindowDialogViewModel()
{
FindNotesCommand = new ControllComands(FindNote);
}
public string SearchString
{
get
{
return searchString;
}
set
{
searchString = value;
OnPropertyChanged();
}
}
public bool SearchByName
{
get
{
return searchByName;
}
set
{
searchByName = value;
OnPropertyChanged("SearchByName");
}
}
public bool SearchByContent
{
get
{
return searchByContent;
}
set
{
searchByContent = value;
OnPropertyChanged("SearchByContent");
}
}
public void FindNote()
{
MessageBox.Show(SearchByName.ToString() + " " + SearchByContent.ToString());
}
public event PropertyChangedEventHandler PropertyChanged;
public void OnPropertyChanged([CallerMemberName]string prop = "")
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(prop));
}
}
How can I use the command contained in FindWindowDialogViewModel to hide rows in the DataGrid MainWindowView ?
I would like something like this: (this is pseudocode)
public void FindNote()
{
foreach(var row in MainWindow.DataGrid.Rows)
{
string searchingText = FindNoteDialog.TextBox.Text;
if (!row.Content.Contains(searchingText))
{
row.Visibillity = false;
}
}
}
For this purpose collections provide filtering via their views (see Binding to collections and CollectionView API remarks to learn more).
Filtering using the collection's view has much better performance than hiding rows or removing items from the original collection.
To do so, you must get the ICollectionView of the source collection
Note.cs
class Note
{
public string Summary { get; set; }
public DateTime Timestamp { get; set; }
}
ViewModel.cs
class ViewModel : INotifyPropertyChanged
{
public ObservableCollection<Note> Notes { get; }
public string SearchKey { get; set; }
public ICommand FilterNotesCommand => new RelayCommand(ExecuteFilterNotes);
private void ExecuteFilterCommands(object commandParameter)
{
ICollectionView notesView = CollectionViewSource.GetDefaultView(this.Notes);
notesView.Filter = item => (item as Note).Summary.Contains(this.SearchKey);
}
}
MainWindow.xaml
<Window>
<Window.DataContext>
<ViewModel />
</Window.DataContext>
<StackPanel>
<TextBox Text="{Binding SearchKey}" />
<Button Command="{Binding FilterNotesCommand}" Content="Filter Table" />
<DataGrid ItemsSource="{Binding Notes}" />
</StackPanel>
</Window>

Editing copies of an ObservableCollection's Object without editing the ObservableCollection

I have a WPF form that I want to use to manipulate a database table. To get the data out of the database I use Entity Framework Core. I try to follow the MVVM pattern.
So I have a Model called Employee with a number of string properties like Firstname and so on.
The form has a ListView that shows an ObservableCollection of Employee. Further I have a number of TextBoxes to display and manipulate the properties of single Employee objects. The selectedMemberPath of the ListView is bound to a property SelectedEmployee. The setter of SelectedEmployee than copies it's own properties to EditedEmployee. The TextBoxes are bound to EditedEmployee. The idea is, that I don't want to directly edit the ObservableCollection. This should only happen if a save button is clicked.
This is my view model.
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.ChangeTracking;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using XdcCore.Models;
using XdcCore.ViewModels.Commands;
namespace XdcCore.ViewModels
{
class EmployeeEditorVM : List<Employee>, INotifyPropertyChanged
{
public EmployeeSaveCommand EmployeeSaveCommand { get; set; }
public EmployeeEditorVM()
{
EmployeeSearch();
EmployeeSaveCommand = new EmployeeSaveCommand(this);
}
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string propertyName)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
private string employeeSearchText;
public string EmployeeSearchText
{
get { return employeeSearchText; }
set
{
employeeSearchText = value;
OnPropertyChanged("EmployeeSearch");
EmployeeSearch();
}
}
private Employee selectedEmployee;
public Employee SelectedEmployee
{
get { return selectedEmployee; }
set
{
selectedEmployee = value;
OnPropertyChanged("SelectedEmployee");
EditedEmployee = SelectedEmployee;
}
}
private Employee editedEmployee;
public Employee EditedEmployee
{
get { return editedEmployee; }
set
{
editedEmployee = value;
OnPropertyChanged("EditedEmployee");
}
}
private ObservableCollection<Employee> employees;
public ObservableCollection<Employee> Employees
{
get { return employees; }
set
{
employees = value;
OnPropertyChanged("Employees");
}
}
public void EmployeeSearch()
{
using (var context = new XdcContext())
{
if (employeeSearchText != null)
{
var _employees = context.Employee
.Where(x => x.Firstname.Contains(employeeSearchText));
Employees = new ObservableCollection<Employee>(_employees);
}
else
{
var _employees = context.Employee.Select(x => x);
Employees = new ObservableCollection<Employee>(_employees);
}
}
}
public void EmployeeSave()
{
using (var context = new XdcContext())
{
var entity = context.Employee.First(x => x.IdEmployee == SelectedEmployee.IdEmployee);
{
entity.Firstname = SelectedEmployee.Firstname;
entity.Lastname = SelectedEmployee.Lastname;
entity.Initials = SelectedEmployee.Initials;
context.SaveChanges();
}
EmployeeSearch();
}
}
}
}
this is my View:
<Window
x:Class="XdcCore.Views.Editors.EmployeeEditor"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:XdcCore.Views.Editors"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:vm="clr-namespace:XdcCore.ViewModels"
Title="Employee"
Width="800"
Height="450"
mc:Ignorable="d">
<Window.Resources>
<vm:EmployeeEditorVM x:Key="vm" />
</Window.Resources>
<Grid DataContext="{StaticResource vm}">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="300" />
<ColumnDefinition Width="115*" />
<ColumnDefinition Width="277*" />
</Grid.ColumnDefinitions>
<!-- left column -->
<Border BorderBrush="DarkGray" BorderThickness="1">
<Grid Grid.Column="0">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="*" />
<RowDefinition Height="aUTO" />
</Grid.RowDefinitions>
<Label
Grid.Row="0"
Margin="3,3,3,3"
Content="Filter:" />
<TextBox
x:Name="TextBoxSearch"
Grid.Row="1"
Height="25"
Margin="3,0,3,3"
HorizontalContentAlignment="Left"
VerticalContentAlignment="Center"
Text="{Binding EmployeeSearchText, Mode=TwoWay}" />
<ListView
x:Name="ListViewOverview"
Grid.Row="2"
Margin="3,0,3,0"
HorizontalAlignment="Stretch"
VerticalAlignment="Stretch"
ItemsSource="{Binding Employees, Mode=OneWay}"
SelectedItem="{Binding SelectedEmployee, Mode=OneWayToSource}">
<ListView.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Initials}" />
<TextBlock Text=" : " />
<TextBlock Text="{Binding Firstname}" />
<TextBlock Text=" " />
<TextBlock Text="{Binding Lastname}" />
</StackPanel>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
<Grid Grid.Row="3">
<Grid.ColumnDefinitions>
<ColumnDefinition />
<ColumnDefinition />
</Grid.ColumnDefinitions>
<Button
x:Name="ButtonDelete"
Grid.Column="0"
Height="25"
Margin="3,3,3,3"
Content="Delete"
IsEnabled="False" />
<Button
x:Name="ButtonNew"
Grid.Column="1"
Height="25"
Margin="3,3,3,3"
Content="Add New ..."
IsEnabled="True" />
</Grid>
</Grid>
</Border>
<!-- right Column -->
<Grid Grid.Column="1" Grid.ColumnSpan="2">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<!-- right column, first row -->
<Border
Grid.Row="0"
BorderBrush="DarkGray"
BorderThickness="1">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="25" />
<RowDefinition Height="25" />
<RowDefinition Height="25" />
<RowDefinition Height="25" />
<RowDefinition Height="25" />
<RowDefinition Height="25" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="100" />
<ColumnDefinition Width="200" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<Label
Grid.Row="0"
Grid.Column="0"
HorizontalAlignment="Right"
Content="First Name" />
<Label
Grid.Row="1"
Grid.Column="0"
HorizontalAlignment="Right"
Content="Last Name" />
<Label
Grid.Row="2"
Grid.Column="0"
HorizontalAlignment="Right"
Content="Initials" />
<Label
Grid.Row="3"
Grid.Column="0"
HorizontalAlignment="Right"
VerticalContentAlignment="Center"
Content="ID" />
<Label
Grid.Row="4"
Grid.Column="0"
HorizontalAlignment="Right"
VerticalContentAlignment="Center"
Content="RCU" />
<Label
Grid.Row="5"
Grid.Column="0"
HorizontalAlignment="Right"
VerticalContentAlignment="Center"
Content="RCT" />
<TextBox
x:Name="TextBoxFirstName"
Grid.Row="0"
Grid.Column="1"
Margin="0,3,3,3"
HorizontalAlignment="Stretch"
VerticalAlignment="Stretch"
HorizontalContentAlignment="Left"
VerticalContentAlignment="Center"
Text="{Binding EditedEmployee.Firstname, Mode=TwoWay}" />
<TextBox
x:Name="TextBoxLastName"
Grid.Row="1"
Grid.Column="1"
Margin="0,3,3,3"
HorizontalAlignment="Stretch"
VerticalAlignment="Stretch"
HorizontalContentAlignment="Left"
VerticalContentAlignment="Center"
Text="{Binding EditedEmployee.Lastname, Mode=TwoWay}" />
<TextBox
x:Name="TextBoxInitials"
Grid.Row="2"
Grid.Column="1"
Margin="0,3,3,3"
HorizontalAlignment="Stretch"
VerticalAlignment="Stretch"
HorizontalContentAlignment="Left"
VerticalContentAlignment="Center"
Text="{Binding EditedEmployee.Initials, Mode=TwoWay}" />
<TextBox
x:Name="TextBoxId"
Grid.Row="3"
Grid.Column="1"
Margin="0,3,3,3"
HorizontalAlignment="Stretch"
VerticalAlignment="Stretch"
HorizontalContentAlignment="Left"
VerticalContentAlignment="Center"
IsReadOnly="True" />
<TextBox
x:Name="TextBoxRCU"
Grid.Row="4"
Grid.Column="1"
Margin="0,3,3,3"
HorizontalAlignment="Stretch"
VerticalAlignment="Stretch"
HorizontalContentAlignment="Left"
VerticalContentAlignment="Center"
IsReadOnly="True" />
<TextBox
x:Name="TextBoxRCT"
Grid.Row="5"
Grid.Column="1"
Margin="0,3,3,3"
HorizontalAlignment="Stretch"
VerticalAlignment="Stretch"
HorizontalContentAlignment="Left"
VerticalContentAlignment="Center"
IsReadOnly="True" />
</Grid>
</Border>
<Grid Grid.Row="1">
<Grid.ColumnDefinitions>
<ColumnDefinition />
<ColumnDefinition />
</Grid.ColumnDefinitions>
<Button
x:Name="ButnSave"
Grid.Column="1"
Width="76"
Height="25"
Margin="60,3,60,0"
HorizontalAlignment="Center"
VerticalAlignment="Top"
Command="{Binding EmployeeSaveCommand}"
Content="Save"
IsEnabled="True" />
</Grid>
<!-- Add new -->
</Grid>
</Grid>
</Grid>
</Window>
In other words: I want to click on an item in the list view, it's details are shown in the text boxes. I can change the text in the text boxes but the changes are not applied to the observable collection (or even database) until I click "save". The problem is, that exactly that happens: when I edit text in the text boxes the changes are also shown in the list view. And I can#t see why.
So, I got the concept of "copy vs point" of a variable wrong.
I had two solutions for my problem.
To my Employee model I added the method Copy:
public partial class Employee
{
public int IdEmployee { get; set; }
public string Initials { get; set; }
public string Firstname { get; set; }
public string Lastname { get; set; }
public string Rcu { get; set; }
public DateTime Rct { get; set; }
public Employee Copy()
{
return (Employee)this.MemberwiseClone();
}
}
Then I Changed my ViewModel so that EditedEmployee is a copy of SelectedEmployee
private Employee selectedEmployee;
public Employee SelectedEmployee
{
get { return selectedEmployee; }
set
{
selectedEmployee = value;
OnPropertyChanged("SelectedEmployee");
if (SelectedEmployee != null)
{
EditedEmployee = SelectedEmployee.Copy();
}
}
}
private Employee editedEmployee;
public Employee EditedEmployee
{
get { return editedEmployee; }
set
{
editedEmployee = value;
OnPropertyChanged("EditedEmployee");
}
}
The problem with this approach is, that if I mess around with the database and then need to run Scaffold-DbContext (I prefer the code-first approach of EFC) again, I would have to modify all models again. A solution to that might be some a second, modified Model that inherits from the original Model and then adds the Copy method.
My second approach is to bind the ListView via SelectedIndex instead of SelectedItem.
<ListView
...
ItemsSource="{Binding Employees, Mode=OneWay}"
SelectedIndex="{Binding SelectedItemIndex, Mode=TwoWay}">
In the ViewModel this is then represented by an int property. If this int is set (and >= 0) Employee gets copied EmployeeWorkingCopy. Furthermore if EmployeeWorkingCopy is set a single Employee dubbed EditedEmployee is set as the Employee of the working copy with the selected index.
private int selectedItemIndex;
public int SelectedItemIndex
{
get { return selectedItemIndex; }
set
{
selectedItemIndex = value;
if (SelectedItemIndex >= 0)
EmployeesWorkingCopy = new ObservableCollection<Employee>(Employees);
}
}
private Employee editedEmployee;
public Employee EditedEmployee
{
get { return editedEmployee; }
set
{
editedEmployee = value;
OnPropertyChanged("EditedEmployee");
}
}
private ObservableCollection<Employee> employeesWorkingCopy;
public ObservableCollection<Employee> EmployeesWorkingCopy
{
get { return employeesWorkingCopy; }
set
{
employeesWorkingCopy = value;
EditedEmployee = EmployeesWorkingCopy[SelectedItemIndex];
}
}
Thanks a lot for pointing out my misconception.

Reporting progress from ViewModel method executed in a Task

i'm trying to report progress from ViewModel (MVVM Light) methods that are executed in a task. The ProgressViewModel contains a ProgressModel property that provides properties to describe the current state. Those properties are bound to an Xceed BusyIndicator. So far, so good. But its not working as expected. The ProgressModel.IsRunning is bound to BusyIndiciator.IsBusy and toggles the visibility - that works. ProgressModel.Description and ProgressModel.Percentage are bound to a TextBlock.Text/ProgressBar.Value - but they are not updated...
So... since IsRunning works, whats wrong with Description and Progress...?
// Model
public sealed class ProgressModel: ObservableObject
{
private string m_description;
private float m_percentage;
private bool m_running;
public string Description
{
get { return m_description; }
set { Set(ref m_description, value); }
}
public float Percentage
{
get { return m_percentage; }
set { Set(ref m_percentage, value); }
}
public bool IsRunning
{
get { return m_running; }
set{Set(ref m_running, value);}
}
public void Initiate()
{
Description = string.Empty;
Percentage = 0;
IsRunning = true;
}
}
// Command
private void DownloadWatch()
{
DispatcherHelper.UIDispatcher.Invoke(() =>
{
Progress.Initiate();
});
using (var watch = new PolarWatch())
{
watch.Connect();
for (var i = 0; i < watch.Sessions.Count; i++)
{
DispatcherHelper.UIDispatcher.Invoke(() =>
{
Progress.Description = $"Writing session data for '{session.DateTime}'...";
});
}
}
DispatcherHelper.UIDispatcher.Invoke(() =>
{
Progress.IsRunning = false;
});
}
// View
<xctk:BusyIndicator Name="Busy" IsBusy="{Binding Progress.IsRunning}">
<xctk:BusyIndicator.BusyContentTemplate>
<DataTemplate>
<Grid Width="150">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="Auto" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition />
</Grid.RowDefinitions>
<TextBlock Grid.Row="0" Grid.Column="0" Text="{Binding Progress.Description}"/>
<ProgressBar Grid.Row="1" Grid.Column="0" Value="{Binding Progress.Percentage}" Height="14" Margin="0,5,0,0"/>
</Grid>
</DataTemplate>
</xctk:BusyIndicator.BusyContentTemplate>
<xctk:BusyIndicator.ProgressBarStyle>
<Style TargetType="ProgressBar">
<Setter Property="Visibility" Value="Collapsed"/>
</Style>
</xctk:BusyIndicator.ProgressBarStyle>
The DataContext of the root element in the ItemTemplate is not the same as the DataContext of the control itself. Try this:
<TextBlock Grid.Row="0" Grid.Column="0" Text="{Binding DataContext.Progress.Description, RelativeSource={RelativeSource AncestorType=xctk:BusyIndicator}}"/>
<ProgressBar Grid.Row="1" Grid.Column="0" Value="{Binding DataContext.Progress.Percentage,RelativeSource={RelativeSource AncestorType=xctk:BusyIndicator}}" Height="14" Margin="0,5,0,0"/>
Or set the DataContext of the Grid:
<Grid Width="150" DataContext="{Binding DataContext.Progress, RelativeSource={RelativeSource AncestorType=xctk:BusyIndicator}}">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="Auto" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition />
</Grid.RowDefinitions>
<TextBlock Grid.Row="0" Grid.Column="0" Text="{Binding Description}"/>
<ProgressBar Grid.Row="1" Grid.Column="0" Value="{Binding Percentage}" Height="14" Margin="0,5,0,0"/>
</Grid>

WPF Data binding alternate datacontext inside Itemscontrol

What I'm trying to do is bind the controls generated by a ItemsControl.ItemTemplate to a new instance of my ContactInterface class that is created whenever I run my query function.
ContactInterface.cs:
class ContactInterface : INotifyPropertyChanged
{
public string Type { get; set; }
private string firstname;
public string FirstName {
get{return this.firstname;}
set {
if (this.firstname != value) {
this.firstname = value;
this.NotifyPropertyChanged("FirstName");
}
}
}
public event PropertyChangedEventHandler PropertyChanged;
public void NotifyPropertyChanged(string propName)
{
if (this.PropertyChanged != null)
this.PropertyChanged(this, new PropertyChangedEventArgs(propName));
}
}
}
SQL.cs
partial class MainWindow
{
private void selectContact(int? contactID)
{
using (ContactsDataContext context = new ContactsDataContext("Data Source=ds;Initial Catalog=db;Integrated Security=True"))
{
Contact contact = context.Contacts.SingleOrDefault(x => x.ContactID == contactID);
Contact spouse = context.Contacts.SingleOrDefault(x => x.ContactID == contact.Spouse);
Property property = context.Properties.SingleOrDefault(x => x.PropertyID == contact.Address);
ContactInterface selectedContact= new ContactInterface();
selectedContact.FirstName = contact.FirstName;
profileGrid.DataContext = selectedContact;
}
}
MainWindow.xaml
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="300" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<ItemsControl Name="Profile_Page_Controls">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<Grid Margin="15">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="100" />
<ColumnDefinition Width="30" />
<ColumnDefinition Width="100" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="43" />
<RowDefinition Height="43" />
<RowDefinition Height="43" />
<RowDefinition Height="43" />
<RowDefinition Height="43" />
<RowDefinition Height="43" />
<RowDefinition Height="43" />
<RowDefinition Height="43" />
</Grid.RowDefinitions>
</Grid>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock Text="{Binding TextContent}"/>
<TextBox Height="23" Text="{Binding Path=FirstName, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged }"/>
</StackPanel>
</DataTemplate>
</ItemsControl.ItemTemplate>
<ItemsControl.ItemContainerStyle>
<Style>
<Setter Property="Grid.Column" Value="{Binding profile_Column}" />
<Setter Property ="Grid.Row" Value="{Binding profile_Row}" />
<Setter Property="Grid.ColumnSpan" Value="{Binding profile_Colspan}" />
</Style>
</ItemsControl.ItemContainerStyle>
</ItemsControl>
<CheckBox Name="profile_SpouseCheck" Grid.Column="1" Margin="0,0,0,0" Checked="profile_SpouseCheck_Checked_1" Unchecked="profile_SpouseCheck_Checked_1"> Spouse</CheckBox>
</Grid>
My plan is to make a new ContactInterface instance every time a user runs the selectContact() function. That new instance will be bound to the generated controls, so when the user makes and saves a change, the textboxes will update that ContactInterface instance and my other functions can grab the data from that ContactInterface to make changes to the database.
Any ideas?

Xaml WinRT Custom User Control with Bindable Collection

I am trying to make a custom user control that I can reuse across all of my views. My BaseViewModel has a property called ViewAlerts that is intended to be used to show alerts consistently across the application (such as successful updates, failed requests, etc.). I was able to get to the point where my custom control is buildable and has a property for binding, but the collection of alerts is never show. I am statically defining some alerts in my base view model for testing purposes, and am not able to get the alerts to show (seems like a problem with an INotifyPropertyChanged but my bindable property inherits from ObservableCollection<> so it should be automatically handling that I think).
Here is my custom control so far:
<UserControl.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="../../Resources/MMJCeoResources.xaml" />
<ResourceDictionary>
<Style TargetType="TextBlock" x:Key="AlertTextStyle">
<Setter Property="FontSize" Value="15"></Setter>
<Setter Property="Margin" Value="10" />
<Setter Property="Padding" Value="10" />
</Style>
<DataTemplate x:Key="DangerAlert">
<Grid Background="LightPink">
<Grid.RowDefinitions>
<RowDefinition Height="*" />
<RowDefinition Height="10*"/>
</Grid.RowDefinitions>
<Border Width="10"
Height="10"
BorderBrush="DarkRed"
HorizontalAlignment="Right"
Margin="5"
Grid.Row="0">
<TextBlock Text="X" />
</Border>
<TextBlock Grid.Row="1" Text="{Binding Message}" Style="{StaticResource AlertTextStyle}" Foreground="DarkRed"/>
</Grid>
</DataTemplate>
<DataTemplate x:Key="SuccessAlert">
<Grid Background="LightGreen">
<Grid.RowDefinitions>
<RowDefinition Height="*" />
<RowDefinition Height="10*"/>
</Grid.RowDefinitions>
<Border Width="10"
Height="10"
BorderBrush="DarkGreen"
HorizontalAlignment="Right"
Margin="5"
Grid.Row="0">
<TextBlock Text="X" />
</Border>
<TextBlock Grid.Row="1" Text="{Binding Message}" Style="{StaticResource AlertTextStyle}" Foreground="DarkGreen"/>
</Grid>
</DataTemplate>
<DataTemplate x:Key="InfoAlert">
<Grid Background="LightGreen">
<Grid.RowDefinitions>
<RowDefinition Height="*" />
<RowDefinition Height="10*"/>
</Grid.RowDefinitions>
<Border Width="10"
Height="10"
BorderBrush="DarkGreen"
HorizontalAlignment="Right"
Margin="5"
Grid.Row="0">
<TextBlock Text="X" />
</Border>
<TextBlock Grid.Row="1" Text="{Binding Message}" Style="{StaticResource AlertTextStyle}" Foreground="DarkGreen"/>
</Grid>
</DataTemplate>
<DataTemplate x:Key="WarningAlert">
<Grid Background="LightSalmon">
<Grid.RowDefinitions>
<RowDefinition Height="*" />
<RowDefinition Height="10*"/>
</Grid.RowDefinitions>
<Border Width="10"
Height="10"
BorderBrush="DarkOrange"
HorizontalAlignment="Right"
Margin="5"
Grid.Row="0">
<TextBlock Text="X" />
</Border>
<TextBlock Grid.Row="1" Text="{Binding Message}" Style="{StaticResource AlertTextStyle}" Foreground="DarkOrange"/>
</Grid>
</DataTemplate>
</ResourceDictionary>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</UserControl.Resources>
<Grid>
<ItemsControl ItemsSource="{Binding Path=Alerts}"
ItemTemplateSelector="{StaticResource AlertDataTemplateSelector}">
</ItemsControl>
</Grid>
</UserControl>
The Code Behind for the control:
public sealed partial class AlertControl : UserControl
{
public static readonly DependencyProperty AlertsProperty = DependencyProperty.Register(
"Alerts", typeof (ObservableList<Alert>), typeof (AlertControl), new PropertyMetadata(default(ObservableList<Alert>), OnAlertsChanged));
public ObservableList<Alert> Alerts
{
get { return (ObservableList<Alert>) GetValue(AlertsProperty); }
set { SetValue(AlertsProperty, value); }
}
//I was trying to adapt another tutorial to what I was trying to accomplish but only got this far
public static void OnAlertsChanged(object sender, DependencyPropertyChangedEventArgs e)
{
var old = e.OldValue as ObservableList<Alert>;
var me = sender as AlertControl;
if (old != null)
{
old.CollectionChanged -= me.OnAlertCollectionChanged;
}
var n = e.NewValue as ObservableList<Alert>;
if (n != null)
n.CollectionChanged += me.OnAlertCollectionChanged;
}
private void OnAlertCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
if (e.Action == NotifyCollectionChangedAction.Reset)
{
Alerts.Clear();
var n = e.NewItems as ObservableList<Alert>;
Alerts.AddRange(n);
}
}
public AlertControl()
{
this.InitializeComponent();
DataContext = this;
}
}
an example implementation:
<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<StackPanel Orientation="Vertical" HorizontalAlignment="Stretch">
<TextBlock Style="{StaticResource PageTitle}" Text="User Information" />
<controls:AlertControl Alerts="{Binding ViewAlerts}" />
in this implementation, the ViewAlerts property has 4 statically defined alerts in it, so I know there are values that should be showing up.
You should give your inner Grid the DataContext to this and not to the Control itself, because then the outer binding will search for your ViewAlerts inside the Control
<Grid x:Name="InnerGrid">
<ItemsControl ItemsSource="{Binding Path=Alerts}"
ItemTemplateSelector="{StaticResource AlertDataTemplateSelector}">
</ItemsControl>
</Grid>
public AlertControl()
{
this.InitializeComponent();
InnerGrid.DataContext = this;
}
After that you can Bind to Alerts, and Alerts will be binded to the ItemsControl inside your InnerGrid

Categories

Resources