I need a simple way to validate of text boxes (Required Field). It should check all mandatory field existence , when user press button.
I have tried this code :
<Window.Resources>
<ControlTemplate x:Key="validationTemplate">
<DockPanel>
<TextBlock Foreground="Red" FontSize="25" Text="*" DockPanel.Dock="Right" />
<AdornedElementPlaceholder/>
</DockPanel>
</ControlTemplate>
</Window.Resources>
<Grid>
<Button Content="Button" HorizontalAlignment="Left" Height="26" Margin="62,213,0,0" VerticalAlignment="Top" Width="121" Click="Button_Click_1"/>
<TextBox x:Name="txtEmail1" Text="" Height="61" Margin="116,10,194,0" Validation.ErrorTemplate="{StaticResource validationTemplate}"/>
</Grid>
please anyone suggest a way to make validation in Text boxes in WPF.
Thank you
You should bind the Text property of the TextBox to a property of a view model and implement the IDataErrorInfo interface in the view model class.
Please refer to the following sample code.
Code:
public partial class Window3 : Window
{
Window3ViewModel viewModel = new Window3ViewModel();
public Window3()
{
InitializeComponent();
DataContext = viewModel;
}
private void Button_Click_1(object sender, RoutedEventArgs e)
{
viewModel.Validate();
}
}
public class Window3ViewModel : INotifyDataErrorInfo
{
private readonly Dictionary<string, string> _validationErrors = new Dictionary<string, string>();
public void Validate()
{
bool isValid = !string.IsNullOrEmpty(_text);
bool contains = _validationErrors.ContainsKey(nameof(Text));
if (!isValid && !contains)
_validationErrors.Add(nameof(Text), "Mandatory field!");
else if (isValid && contains)
_validationErrors.Remove(nameof(Text));
if (ErrorsChanged != null)
ErrorsChanged(this, new DataErrorsChangedEventArgs(nameof(Text)));
}
public bool HasErrors => _validationErrors.Count > 0;
public event EventHandler<DataErrorsChangedEventArgs> ErrorsChanged;
public IEnumerable GetErrors(string propertyName)
{
string message;
if (_validationErrors.TryGetValue(propertyName, out message))
return new List<string> { message };
return null;
}
private string _text;
public string Text
{
get { return _text; }
set
{
_text = value;
}
}
}
XAML:
<Window x:Class="WpfApp2.Window3"
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:WpfApp2"
mc:Ignorable="d"
Title="Window3" Height="300" Width="300">
<Window.Resources>
<ControlTemplate x:Key="validationTemplate">
<DockPanel>
<TextBlock Foreground="Red" FontSize="25" Text="*" DockPanel.Dock="Right" />
<AdornedElementPlaceholder/>
</DockPanel>
</ControlTemplate>
</Window.Resources>
<Grid>
<Button Content="Button" HorizontalAlignment="Left" Height="26" Margin="62,213,0,0" VerticalAlignment="Top" Width="121" Click="Button_Click_1"/>
<TextBox x:Name="txtEmail1" Text="{Binding Text}" Height="61" Margin="116,10,194,0" Validation.ErrorTemplate="{StaticResource validationTemplate}"/>
</Grid>
</Window>
And please refer to the following blog post for more information about how data validation in WPF works.
Data validation in WPF: https://blog.magnusmontin.net/2013/08/26/data-validation-in-wpf/
I will show you how you can validate data using IDataErrorInfo. This interface has only two members which need to be implemented:
public string Error { get; } - gets an error message indicating what is wrong with this object
public string this[string columnName] { get; } - get the error message for the property with the given name.
Once you implement the IDataErrorInfo you need to set the ValidatesOnDataErrors to true in the element that you want to validate. To simplify the code example, I implemented IDataErrorInfo in the MainViewModel as you can see below:
public class MainViewModel : BindableBase, IDataErrorInfo
{
private string _firstName;
private string _lastName;
public string FirstName
{
get { return _firstName; }
set { _firstName = value; RaisePropertyChanged(); }
}
public string LastName
{
get { return _lastName; }
set { _lastName = value; RaisePropertyChanged(); }
}
public string this[string columnName]
{
get
{
string error = string.Empty;
switch (columnName)
{
case nameof(FirstName):
if (string.IsNullOrWhiteSpace(FirstName))
error = "First name cannot be empty.";
if (FirstName?.Length > 50)
error = "The name must be less than 50 characters.";
break;
case nameof(LastName):
if (string.IsNullOrWhiteSpace(LastName))
error = "Last name cannot be empty.";
break;
}
return error;
}
}
public string Error => string.Empty;
}
and in the TextBox element, I set ValidatesOnDataErrors to true:
<TextBox Text="{Binding FirstName, Mode=TwoWay,
UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=True}" />
Related
I'm learning MVVM pattern and I have a simple issue.
I have created a class whose properties I want to bind into text boxes inside a Dialog (in this case I only have one property):
public class NewObjectClass : ObservableObject
{
private string _name;
public string Name
{
get { return _name; }
set
{
_name = value;
OnPropertyChanged("Name");
}
}
}
This is the ViewModel of the Dialog:
class ObjCreationViewModel : ObservableObject
{
// Class whose properties I want to bind in text boxes
private NewObjectClass _newObject;
public NewObjectClass NewObject
{
get { return _newObject; }
set { _newObject = value;
OnPropertyChanged("NewObject");
}
}
// String to test binding
private string _test;
public string Test
{
get { return _test; }
set { _test = value; }
}
// Create new object view
private DelegateCommand _createNewObject;
public DelegateCommand CreateNewObjectCmd => _createNewObject ?? (_createNewObject = new DelegateCommand(CreateNewObject));
void CreateNewObject()
{
// Do things in the future
}
public ObjCreationViewModel()
{
// Instance of New Object
NewObjectClass NewObject = new NewObjectClass();
// New object property that I want to show in TextBox
NewObject.Name = "Why this one is not working?";
// String text that works
Test = "Why this is working?";
}
}
And finally this is the view:
<UserControl x:Class="AOE.MVVM.View.ObjCreationView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:AOE.MVVM.View"
xmlns:viewmodel="clr-namespace:AOE.MVVM.ViewModel"
mc:Ignorable="d"
MinHeight="500" MinWidth="500">
<UserControl.DataContext>
<viewmodel:ObjCreationViewModel/>
</UserControl.DataContext>
<Border Grid.ColumnSpan="4" CornerRadius="20"
Background="White" BorderBrush="Black" BorderThickness="1.5">
<Grid HorizontalAlignment="Stretch">
<Grid.RowDefinitions>
<RowDefinition Height="30"/>
<RowDefinition/>
<RowDefinition Height="30"/>
</Grid.RowDefinitions>
<StackPanel Grid.Row="1">
<StackPanel Orientation="Horizontal">
<Label Margin="10" Content="Object name:" Style="{StaticResource DescriptionLabelStyle}"/>
<TextBox x:Name="TextObjectName" Width="200" Height="25" Text="{Binding NewObject.Name, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}"/>
</StackPanel>
</StackPanel>
<Button Grid.Row="1" Margin="5" Name="CreateBtn" Width="75" Height="30" Content="Create" FontFamily="Verdana" Foreground="#007BC0" FontWeight="Bold" Background="Transparent" BorderThickness="3" BorderBrush="#007BC0" VerticalAlignment="Bottom" Command="{Binding CreateNewObjectCmd}"/>
</Grid>
</Border>
The issue is that I can't bind the property Name of "NewObject" into the text box, however if I bind "Test", It works properly.
I want to show in the textbox the property value and also if I change the value in the textbox, change the property value of the instance "NewObject".
Anybody could tell me what is wrong?
PD "ObservableObject class that implements PropertyChange event":
public class ObservableObject : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
public void OnPropertyChanged([CallerMemberName] string propertyname = null)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyname));
}
}
The line
NewObjectClass NewObject = new NewObjectClass();
defines a local variable NewObject, but does not set the property NewObject.
Change it to
NewObject = new NewObjectClass();
This question already has answers here:
How to use DataTemplateSelector with ContentControl to display different controls based on the view-model?
(2 answers)
Closed 4 years ago.
I'm trying to write a simple dialog that would accept a value in a SpinEdit or a text in a TextEdit. I'm using multiple VMs and I made a selector that should view a proper control based on the logic in the c++/cli file.
XAML:
xmlns:local="clr-namespace:asd"
Title="{Binding Path=Title, Mode=OneTime}"
<dx:DXWindow.Resources>
<DataTemplate x:Key="TInputValueVM" DataType="{x:Type local:TInputValueVM}">
<dxe:SpinEdit Height="23" Width="200"
Text="{Binding Value, Mode=TwoWay}"
Mask="{Binding Mask, Mode=OneWay}"
MaxLength="{Binding Path=InputLength}" />
</DataTemplate>
<DataTemplate x:Key="TInputTextVM" DataType="{x:Type local:TInputTextVM}">
<dxe:TextEdit Height="23" Width="200"
Text="{Binding Value, Mode=TwoWay}"
MaskType="RegEx" Mask="{Binding Mask, Mode=OneWay}"
MaxLength="{Binding Path=InputLength}"/>
</DataTemplate>
<local:PropertyDataTemplateSelector x:Key="templateSelector"
DataTemplate_Value="{StaticResource TInputValueVM}"
DataTemplate_Text="{StaticResource TInputTextVM}" />
</dx:DXWindow.Resources>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<StackPanel Grid.Row="0" >
<Label x:Uid="Label" MinHeight="24" MinWidth="60" Content="Value" />
<ContentControl Content="{Binding Path=Whoami}" ContentTemplateSelector="{StaticResource templateSelector}" />
</StackPanel>
<StackPanel Grid.Row="1" x:Uid="OKCancel_Buttons" Orientation="Horizontal" HorizontalAlignment="Right" VerticalAlignment="Bottom">
<Button Height="23" x:Name="OK_Button" Click="OK_Click" Content="OK" IsDefault="True" HorizontalAlignment="Right" MinWidth="95" />
<Button Height="23" x:Name="Cancel_Button" Click="Cancel_Click" Content="Cancel" HorizontalAlignment="Right" MinWidth="95" />
</StackPanel>
</Grid>
In c# I have a base VM and two VMS that extend it, one for values and one for text. The rest of the properties stay the same.
C#
namespace asd
{
public class TInputBaseVM : ViewModelBase
{
private string m_sTitle;
private string m_sMask;
private int m_nInputLenght;
private string m_sWhoami;
public TInputBaseVM(string A_sTitle, string A_sMask, int A_nInputLength)
{
m_sTitle = A_sTitle;
m_sMask = A_sMask;
m_nInputLenght = A_nInputLength;
}
protected string Title
{
get { return m_sTitle; }
set { SetProperty(ref m_sTitle, value, () => Title); }
}
protected string Mask
{
get { return m_sMask; }
set { SetProperty(ref m_sMask, value, () => Mask); }
}
protected int InputLength
{
get { return m_nInputLenght; }
set { SetProperty(ref m_nInputLenght, value, () => InputLength); }
}
protected string Whoami
{
get { return m_sWhoami; }
set { SetProperty(ref m_sWhoami, value, () => Whoami); }
}
}
public class TInputValueVM : TInputBaseVM
{
public TInputValueVM(string A_sTitle, string A_sMask, int A_nInputLength, double A_nValue) : base(A_sTitle, A_sMask, A_nInputLength)
{
Value = A_nValue;
Whoami = "Value";
}
private double m_nValue;
public double Value
{
get { return m_nValue; }
set { SetProperty(ref m_nValue, value, () => Value); }
}
}
public class TInputTextVM : TInputBaseVM
{
public TInputTextVM(string A_sTitle, string A_sMask, int A_nInputLength, string A_sValue) : base(A_sTitle, A_sMask, A_nInputLength)
{
Value = A_sValue;
Whoami = "Text";
}
private string m_sValue;
public string Value
{
get { return m_sValue; }
set { SetProperty(ref m_sValue, value, () => Value); }
}
}
public class PropertyDataTemplateSelector : DataTemplateSelector
{
public DataTemplate DataTemplate_Value { get; set; }
public DataTemplate DataTemplate_Text { get; set; }
public override DataTemplate SelectTemplate(object item, DependencyObject container)
{
var selector = item as string;
if(selector == "Value")
return DataTemplate_Value;
return DataTemplate_Text;
}
}
}
In c++/cli I create an object of a proper VM and I'd like the WPF to automatically update the view to either spinedit or textedit, however I'm not sure how to properly bind the properties from the C#. If I explicitly type 'Value' in the Content property of the ContentControl then it displays the spinEdit but I don't know how to bind it so it automatically takes the correct property.
EDIT: I'm adding c++/cli code to show how I choose different VMs
C++/cli:
bool TSignalNumberPositionDialogCLR::StartDialog(TSignalNumberPositionSupport& A_Attributes, HWND A_hwndParent, LPTSTR String)
{
try
{
TInputValueVM ^oExchange_Value;
TInputTextVM ^oExchange_Text;
int inputFormat = A_Attributes.GetInputFormat();
if(inputFormat)
oExchange_Text = gcnew TInputTextVM(gcnew System::String(A_Attributes.GetTitle()), gcnew System::String(A_Attributes.GetMask()),
A_Attributes.GetInputLength(), gcnew System::String(A_Attributes.GetInitialText()));
else
oExchange_Value = gcnew TInputValueVM(gcnew System::String(A_Attributes.GetTitle()), gcnew System::String(A_Attributes.GetMask()),
A_Attributes.GetInputLength(), A_Attributes.GetInitialValue());
Dialogs::TSignalNumberPositionDialog^ dialog = gcnew Dialogs::TSignalNumberPositionDialog();
if(inputFormat)
dialog->DataContext = oExchange_Text;
else
dialog->DataContext = oExchange_Value;
dialog->ShowDialog();
if(dialog->DialogResult)
{
CString nValue;
if(inputFormat)
nValue = oExchange_Text->Value;
else
nValue = ((Decimal)oExchange_Value->Value).ToString("F2", CultureInfo::InvariantCulture);
A_Attributes.UpdateValue(nValue, String, A_Attributes.GetInputLength());
return true;
}
return false;
}
catch(Exception^ e)
{
e;
}
}
based on the 'inputFormat' variable I want to display different controls in the dialog.
EDIT: Based on #Clemens comments I got rid of the selector sectionand the x:Key property in the DataTemplates. I changed the content opf the Content property to Content="{Binding}" and it somehow works. The moment I create a VM it selects the correct one.
Based on your comment. Let me improve my answer. As you are facing issue in VM selection. so plesae concentrate how I assigned VM to datatemplate. Although it is done in very basic way, you can handle it if you you are using MVVM packages.
I have created 2 data template and 2 vms and each vm is bound to datatemplate. To verify, I have a combobox, which will select datatemplate based on selected value.
Here is Sample VM
public class VM : System.ComponentModel.INotifyPropertyChanged
{
private string title;
private SolidColorBrush background;
public string Title { get => title; set { title = value; RaisePropertyChanged(); } }
public SolidColorBrush Background { get => background; set { background = value; RaisePropertyChanged(); } }
public event PropertyChangedEventHandler PropertyChanged;
private void RaisePropertyChanged([System.Runtime.CompilerServices.CallerMemberName] string name = "")
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));
}
}
public class VM1: VM
{
public VM1()
{
Title = "This is VM1";
Background = Brushes.Yellow;
}
}
public class VM2: VM
{
public VM2()
{
Title = "This is VM2";
Background = Brushes.Orange;
}
}
Now check for resources
<local:VM1 x:Key="VM1"/>
<local:VM2 x:Key="VM2"/>
<DataTemplate x:Key="DT1">
<Grid DataContext="{StaticResource VM1}">
<TextBlock Text="{Binding Title}" Background="{Binding Background}"/>
</Grid>
</DataTemplate>
<DataTemplate x:Key="DT2">
<Grid DataContext="{StaticResource VM2}">
<TextBlock Text="{Binding Title}" Background="{Binding Background}"/>
</Grid>
</DataTemplate>
<Style TargetType="ContentControl" x:Key="contentStyle">
<Style.Triggers>
<DataTrigger Binding="{Binding ElementName=cmbo, Path=SelectedValue}" Value="Template1">
<Setter Property="ContentTemplate" Value="{StaticResource DT1}" />
</DataTrigger>
<DataTrigger Binding="{Binding ElementName=cmbo, Path=SelectedValue}" Value="Template2">
<Setter Property="ContentTemplate" Value="{StaticResource DT2}" />
</DataTrigger>
</Style.Triggers>
</Style>
and finally I have combobox and content control just to verify
<ComboBox Name="cmbo"/>
<ContentControl Style="{StaticResource contentStyle}"/>
where cmbo.ItemsSource = new List { "Template1", "Template2" };
Hope you got the point
I'm trying to create a UI with WPF using MVVM, but I'm having a bit of trouble. I want to have a DataGrid with two columns. The first column will be a label, and the second column will have a ComboBox in it. The label column always shows up, but nothing ever shows up in the ComboBox. I'm don't think I'm binding it properly, but I'm not sure how to fix it.
I created a class with the properties that I want to appear in the DataGrid. The label will be the Parameter property and I have a list property called Revisions for the ComboBox.
class RevisionMapModel
{
private string _parameter;
public string Parameter
{
get { return _parameter; }
}
private List<string> _revisions;
public List<string> Revisions
{
get { return _revisions; }
}
private string _selection;
public string Selection
{
get { return _selection; }
set { _selection = value; }
}
public RevisionMapModel(string parameter, List<string> revisions)
{
// set the parameter name and the list of revisions
_parameter = parameter;
_revisions = revisions;
_selection = "";
// add a default revision
_revisions.Add("None");
// attempt to find which revision matches with this parameter
FullRevisionMatch(_parameter, _revisions);
// if a full match isn't found, then try again
if (_selection == "None")
{
PartialRevisionMatch(_parameter, _revisions);
}
}
}
Here is the ViewModel class that serves as the DataContext. The DataGrid is bound to the RevisionMapModels property, which is a list of the previous class.
class RevisionMapViewModel
{
private string _label;
public string Label
{
get { return _label; }
}
private List<RevisionMapModel> _revisionMapModels;
public List<RevisionMapModel> RevisionMapModels
{
get { return _revisionMapModels; }
}
public RevisionMapViewModel(List<Definition> parameters, List<Revision> revisions, string label)
{
// instantiate the list
_revisionMapModels = new List<RevisionMapModel>();
_label = label;
// convert the parameters and revisions to strings
List<string> revisionDescriptions = revisions.Select(r => r.Description).ToList();
List<string> parameterNames = parameters.Select(p => p.Name).ToList();
// create classes for each parameter
List<string> reservedRevisions = new List<string>();
for (int i=0; i< parameterNames.Count; i++)
{
RevisionMapModel model = new RevisionMapModel(parameterNames[i], revisionDescriptions);
// check to ensure this parameter is not mapped to a revision that is already selected
if (reservedRevisions.Contains(model.Selection))
{
// change the selection to none if it's already used
model.Selection = "None";
}
else
{
reservedRevisions.Add(model.Selection);
}
// add it to the list
_revisionMapModels.Add(model);
}
}
}
This is my XAML below. I'm guessing it's having trouble binding to the Revisions property because it's a list. I've tried a number of things, but nothing seems to get this to show up.
<Window x:Class="SheetRevisions.RevisionMapView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:SheetRevisions"
mc:Ignorable="d"
d:DesignHeight="450" d:DesignWidth="800" MinWidth="500" MinHeight="500" Width="500">
<Grid>
<DataGrid Margin="20,40,20,45" MinWidth="50" MinHeight="47" ItemsSource="{Binding RevisionMapModels}" AutoGenerateColumns="False">
<DataGrid.Columns>
<DataGridTextColumn Header="Parameter Name" Binding="{Binding Parameter}" Width="Auto"/>
<DataGridComboBoxColumn Header="Revision Description" ItemsSource="{Binding Revisions}" Width="*" />
</DataGrid.Columns>
</DataGrid>
<Label Content="{Binding Label}" HorizontalAlignment="Left" Height="25" Margin="20,10,0,0" VerticalAlignment="Top" Width="412"/>
<Button Content="Cancel" HorizontalAlignment="Right" Margin="0,0,20,10" VerticalAlignment="Bottom" Width="75" IsCancel="True"/>
<Button Content="OK" HorizontalAlignment="Right" Margin="0,0,110,10" VerticalAlignment="Bottom" Width="75" IsDefault="True"/>
</Grid>
</Window>
I'm really new to WPF so any help is appreciated.
As already mentioned here, you need to implement INotifyPropertyChanged in your ViewModel. Something like
RevisionMapViewModel : INotifyPropertyChanged
//...your code here
public event PropertyChangedEventHandler PropertyChanged;
protected void NotifyPropertyChanged(String info) {
if (PropertyChanged != null) {
PropertyChanged(this, new PropertyChangedEventArgs(info));
}
}
Then, RevisionMapModel should be a public class, as I think.
Also, in case you work in Visual Studio, some tips about your incorrect bindings can be visible in Output window.
In addition to the comments above about implimenting INotifyPropertyChanged I also needed to change my XAML to use a DataGridTemplateColumn rather than a DataGridComboBoxColumn. It has something to do with a list not being a valid source as I found out from this post:
https://social.msdn.microsoft.com/Forums/en-US/e14be49f-1c03-420e-8a15-ca98e7eedaa2/how-to-bind-net-4-datagridcomboboxcolumn-to-a-collection-within-a-collection?forum=wpf
Working XAML:
<Window x:Class="SheetRevisions.RevisionMapView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:SheetRevisions"
mc:Ignorable="d"
d:DesignHeight="450" d:DesignWidth="800" MinWidth="500" MinHeight="500" Width="500">
<Grid>
<DataGrid Margin="20,40,20,45" MinWidth="50" MinHeight="47" ItemsSource="{Binding RevisionMapModels}" AutoGenerateColumns="False">
<DataGrid.Columns>
<DataGridTextColumn Header="Parameter Name" Binding="{Binding Parameter}" Width="*" IsReadOnly="True"/>
<DataGridTemplateColumn>
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<ComboBox ItemsSource="{Binding Revisions}" SelectedItem="{Binding Selection}" Width="Auto"/>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
<Label Content="{Binding Label}" HorizontalAlignment="Left" Height="25" Margin="20,10,0,0" VerticalAlignment="Top" Width="412"/>
<Button Content="Cancel" HorizontalAlignment="Right" Margin="0,0,20,10" VerticalAlignment="Bottom" Width="75" IsCancel="True"/>
<Button Content="OK" HorizontalAlignment="Right" Margin="0,0,110,10" VerticalAlignment="Bottom" Width="75" IsDefault="True"/>
</Grid>
</Window>
Revised model:
public class RevisionMapModel : INotifyPropertyChanged
{
#region fields
private Logger _logger = LogUtils.LogFactory.GetCurrentClassLogger();
private string _parameter;
public string Parameter
{
get { return _parameter; }
set { }
}
private List<string> _revisions;
public List<string> Revisions
{
get { return _revisions; }
}
private string _selection;
public string Selection
{
get { return _selection; }
set
{
_selection = value;
OnPropertyRaised("Selection");
}
}
public event PropertyChangedEventHandler PropertyChanged;
public RevisionMapModel(string parameter, List<string> revisions)
{
// set the parameter name and the list of revisions
_parameter = parameter;
_revisions = revisions;
_selection = "";
// add a default revision
_revisions.Add("None");
// attempt to find which revision matches with this parameter
FullRevisionMatch(_parameter, _revisions);
// if a full match isn't found, then try again
if (_selection == "None")
{
PartialRevisionMatch(_parameter, _revisions);
}
}
protected void OnPropertyRaised(string propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
I had a research by criteria with Two combobox, it works fine
after the research is finished, I have a button Display All : to reset the combobox to null..and the DataGrid display with all elements ,
The problem that the combobox must be empty when I click on the Button Dispaly All!
Without select an element in combobox(just dispaly the datagrid):I have 6 elements in the datagrid, it is correct..and the combobox are Empty
After select the Search criteria, i have the result correct: (I have just 3 results, it is the correct action)
3 elements picture
When I click on the button Display All:(I have all the elements in datagrid, 6 elements..It is correct) But the Combobox aren't empty!!
6 elements picture
The view:
<Window x:Class="WPFAuthentification.Views.BusinesseventsView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" >
<Label Content="Entity Type" Width="128" Grid.Row="1" Grid.ColumnSpan="2"/>
<ComboBox HorizontalAlignment="Center" VerticalAlignment="Center"
ItemsSource="{Binding EntityLevelEnum}"
SelectedItem="{Binding EntityType, Mode=TwoWay,UpdateSourceTrigger=PropertyChanged, NotifyOnValidationError=True, TargetNullValue=''}"
Grid.ColumnSpan="2" Grid.Column="1" />
<Button Content="Dislplay all" ToolTip="Display All Business Events"
VerticalAlignment="Top" Command="{Binding Initialize}"
Visibility="{Binding Path=ShowDisplayAllButton, Converter={StaticResource BoolToVis}}" />
<DataGrid ..... />
</Window>
The ViewModel:
class BusinesseventsViewModel : ViewModelBase1
{
private ObservableCollection<BusinessEventClass> businessEventsList;
private RelayCommand<string> initialize;
public RelayCommand<string> Initialize
{
get { return initialize; }
}
public BusinesseventsViewModel()
{
//businessEventsList: to Get all the Business events
businessEventsList = new ObservableCollection<BusinessEventClass>(WCFclient.getAllBusinessEvent());
//Enumeration of Entity Type and Criticality
levelCriticalityEnum = new ObservableCollection<Level_Criticality>(Enum.GetValues(typeof(Level_Criticality)).Cast<Level_Criticality>());
entityLevelEnum = new ObservableCollection<BusinessEntityLevel>(Enum.GetValues(typeof(BusinessEntityLevel)).Cast<BusinessEntityLevel>());
//the Button Display All :
initialize = new RelayCommand<string>(initFunc);
}
//Function of the Button Display All
private void initFunc(object obj)
{
EntityType = null;
OnPropertyChanged("EntityLevelEnum");
Criticality = null;
OnPropertyChanged("Criticality");
}
private string entityType;
public string EntityType
{
get { return entityType; }
set
{
entityType = value;
businessEventsList = filterByCriteria(entityType, criticality);
OnPropertyChanged("BusinessEventsList");
OnPropertyChanged("EntityType");
}
}
//Function of the research :
public ObservableCollection<BusinessEventClass> filterByCriteria(string entityType, string criticality)
{
BusinessEventsList = new ObservableCollection<BusinessEventClass>(WCFclient.getAllBusinessEvent());
ObservableCollection<BusinessEventClass> updatedList = new ObservableCollection<BusinessEventClass>();
if ((entityType == null) && (Criticality == null))
{
updatedList = businessEventsList;
}
if ((entityType != null && entityType != "") && (Criticality != null))
{
updatedList = new ObservableCollection<BusinessEventClass>(BusinessEventsList.Where(a => a.EntityType.ToString().ToLower().Equals(criticality.ToString())
&& a.Critciality.ToString().Equals(criticality.ToString())));
}
}
There must be something wrong with your implementation of the INotifyPropertyChanged interface.
Using GalaSoft.MvvmLight I did this, and works without problem;
Window.cs content:
public partial class MainWindow
{
public MainWindow()
{
InitializeComponent();
DataContext = new TestViewModel();
}
}
public class TestViewModel : ViewModelBase
{
private string _selectedItem;
public RelayCommand Command { get; }
public ObservableCollection<string> ItemsSource { get; }
public string SelectedItem
{
get { return _selectedItem; }
set { Set(ref _selectedItem, value); }
}
public TestViewModel()
{
Command = new RelayCommand(() => SelectedItem = null);
ItemsSource = new ObservableCollection<string> { "index 0", "index 1", "index 2", "index 3" };
}
}
and my Window.xaml content
<Window.Resources>
<ResourceDictionary>
<DataTemplate DataType="{x:Type testClean:TestViewModel}">
<Grid>
<Viewbox>
<TextBlock Foreground="HotPink">just some pink text</TextBlock>
</Viewbox>
<ComboBox Height="50" Width="200" VerticalAlignment="Top" HorizontalAlignment="Left" Margin="20" SelectedIndex="0"
ItemsSource="{Binding ItemsSource}"
SelectedItem="{Binding SelectedItem}"/>
<Button Command="{Binding Command}" Height="50" Width="100" VerticalAlignment="Top" HorizontalAlignment="Left" Margin="250,20,20,20">Reset</Button>
</Grid>
</DataTemplate>
</ResourceDictionary>
</Window.Resources>
<ContentControl Content="{Binding}" />
Tested and working as expected (when you put null as SelectedItem the combobox returns empty)
So I have a simple UDP chat app from a WinForm project, which I wanted to look a little bit better, so I am re-making it in WPF. As I realized I can easily put 2 or more TextBlocks inside of a ListItem, I wanted to display the last message of each chat, like so:
But I have no Idea on how to edit those TextBlocks :( I literary just started with WPF, so I bet I just made a duplicate, but because of that, I don't even know how to search for this issue.
Here is the custom ListBox:
<ListBox x:Name="myList" HorizontalAlignment="Left" Width="264" ScrollViewer.VerticalScrollBarVisibility="Hidden" ScrollViewer.HorizontalScrollBarVisibility="Disabled" BorderThickness="0,1,1,0" MouseLeftButtonUp="myList_MouseLeftButtonUp" Margin="0,25,0,0">
<ListBox.ItemTemplate>
<DataTemplate>
<Border BorderBrush="LightGray" BorderThickness="0,0,0,1" Width="250">
<DockPanel Margin="0,7">
<Ellipse Name="ellipse" Margin="5" DockPanel.Dock="Left" Style="{DynamicResource elstyle}">
</Ellipse>
<TextBlock Text="{Binding Name}" DockPanel.Dock="Top" Margin="0,0,0,7" FontWeight="Bold" MaxWidth="250"></TextBlock>
<TextBlock Text="{Binding ID}" DockPanel.Dock="Top" Visibility="Hidden" FontSize="1.333"></TextBlock>
<TextBlock x:Name="last_message" Text="{Binding LastMessage}" DockPanel.Dock="Bottom" MaxWidth="250"></TextBlock>
</DockPanel>
</Border>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
This is simplified model to show the principal but if you would create view model class that implement INotifyPropertyChanged interface to hold your item data
public class MyItem : INotifyPropertyChanged
{
private string _name;
private string _id;
private string _lastMessage;
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string propertyName)
{
var handler = this.PropertyChanged;
if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
}
public string Name
{
get { return _name; }
set
{
_name = value;
OnPropertyChanged("Name");
}
}
public string ID
{
get { return _id; }
set
{
_id = value;
OnPropertyChanged("ID");
}
}
public string LastMessage
{
get { return _lastMessage; }
set
{
_lastMessage = value;
OnPropertyChanged("LastMessage");
}
}
}
and then in your window
public partial class MainWindow : Window
{
private readonly ObservableCollection<MyItem> _myItems = new ObservableCollection<MyItem>();
public MainWindow()
{
InitializeComponent();
myList.ItemsSource = _myItems;
_myItems.Add(new MyItem { Name = "name", ID = "id", LastMessage = "last message" });
_myItems[0].LastMessage = "new message";
}
}
and then you don't operate on myList control anymore but on _myItems list and its items. If you add/remove item in the collection it will add/remove item in the UI, if you change property of an item it will update bound property in the UI