I am trying to use the DataGridCheckBoxColumn in a grid and I noticed it has no events for checked or unchecked, for some reason.
I was trying to add attached events to this by creating a custom CBColumn class that inherits DataGridCheckBoxColumn.
The problem I am running into is that I am not sure how to add the handler to the exposed property since DataGridCheckBoxColumn is not derived from UIElement.
Therefore AddHandler and RemoveHandler are not available in this code block:
public event RoutedEventHandler Checked
{
add { AddHandler(CheckedEvent, value); }
remove { RemoveHandler(CheckedEvent, value); }
}
Any ideas on how to do this? I have looked all over with no luck.
EDIT: I am using MVVM, so I need to avoid Code Behind if possible.
Click event for DataGridCheckBoxColumn
<DataGridCheckBoxColumn Binding="{Binding Path=LikeCar}" Header="LikeCar">
<DataGridCheckBoxColumn.CellStyle>
<Style>
<EventSetter Event="CheckBox.Checked" Handler="OnChecked"/>
</Style>
</DataGridCheckBoxColumn.CellStyle>
</DataGridCheckBoxColumn>
Here is another solution in code. This is really rough, but it demonstrates the checked box and show a number values of what is checked in a text box.
<Window x:Class="DataGridCheckBoxItemTest.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:vm="clr-namespace:DataGridCheckBoxItemTest"
Title="MainWindow" Height="350" Width="525">
<Window.DataContext>
<vm:DataGridTestVM />
</Window.DataContext>
<Grid>
<DataGrid ItemsSource="{Binding Source}"
SelectedValue="{Binding Selected, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
Margin="10">
<DataGrid.Columns>
<DataGridCheckBoxColumn Header="Test Checked" Binding="{Binding S}"/>
</DataGrid.Columns>
</DataGrid>
<TextBox HorizontalAlignment="Left"
Text="{Binding Test, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}"
Height="39"
Margin="20,244,0,0"
TextWrapping="Wrap"
VerticalAlignment="Top"
Width="237"/>
</Grid>
namespace DataGridCheckBoxItemTest
{
public class DataGridTestVM : INotifyPropertyChanged
{
ObservableCollection<Source> source;
Source s;
int test;
public DataGridTestVM()
{
source = new ObservableCollection<Source>();
for (int i = 0; i < 10; i++)
{
s = new Source();
s.test = i;
source.Add(s);
}
}
public ObservableCollection<Source> Source
{
get
{
return source;
}
set
{
source = value;
OnPropertyChanged("Source");
}
}
public int Test
{
get
{
return test;
}
set
{
test = value;
OnPropertyChanged("Test");
}
}
public Source Selected
{
get
{
return s;
}
set
{
s = value;
Test = s.test;
OnPropertyChanged("Selected");
}
}
public event PropertyChangedEventHandler PropertyChanged;
public void OnPropertyChanged(string name)
{
if (this.PropertyChanged != null)
{
this.PropertyChanged(this, new PropertyChangedEventArgs(name));
}
}
}
public class Source
{
public int test;
}
}
I ended up just reverting to a DataGridTemplateColumn and using the checkbox control in there. Didn't seem like there was a way to do what I wanted.
Related
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 have a user control that I am using to populate a datagrid.
I would like the user to be able to add items by editing the empty row at the bottom. (This is why I am using a datagrid rather than an itemscontrol) However the datagrid does not realise that the last item is edited unless the user clicks the background of the control. I would like the new item to be added when the user makes changes on the properties that the control exposes.
XAML of the control:
<UserControl x:Class="ControlTest.MyControl"
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:ControlTest"
mc:Ignorable="d"
d:DesignHeight="50" d:DesignWidth="300"
DataContext="{Binding Path=., Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"
>
<StackPanel Orientation="Vertical">
<TextBox Text="{Binding Path=p1, Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"
Width="300"
Height="30"
VerticalAlignment="Center"/>
<ComboBox ItemsSource="{Binding Path=DropDownValues,
RelativeSource={RelativeSource Mode=FindAncestor,
AncestorType=local:MyControl}}"
SelectedItem="{Binding Path=p2, Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"
Height="30"/>
</StackPanel>
</UserControl>
cs:
public partial class MyControl : UserControl
{
private static readonly DependencyProperty DropDownValuesProperty =
DependencyProperty.Register(
"DropDownValues",
typeof(List<String>),
typeof(MyControl),
new FrameworkPropertyMetadata(new List<String>()
));
public List<String> DropDownValues
{
get
{
return (List<String>)GetValue(DropDownValuesProperty);
}
set
{
SetValue(DropDownValuesProperty, value);
}
}
public MyControl()
{
InitializeComponent();
}
}
DataGrid XAML
<DataGrid
AutoGenerateColumns="False"
ItemsSource="{Binding objs, Mode=TwoWay}"
HeadersVisibility="None"
Margin="0,0,0.4,0"
CanUserAddRows="True"
>
<DataGrid.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal"/>
</ItemsPanelTemplate>
</DataGrid.ItemsPanel>
<DataGrid.Columns>
<DataGridTemplateColumn Width="300">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate DataType="local:Measure">
<local:MyControl
DataContext="{Binding ., Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
DropDownValues=
"{Binding DataContext.list, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}}"
Width="300"
/>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
Can I make this work, and/or is there a better way to do this?
I would like to suggest you a different way of doing that:
set CanUserAddRows=false on your DataGrid and then manually add rows to the ObservableCollection<Something> to which your DataGrid is bound to.
OR
If you are still interested in the approach that you follow:
In your xaml file:
<DataGrid x:Name="myDataGrid" CellEditEnding="DataGrid_CellEditEnding" .....>
<!--Some Code-->
</DataGrid>
Then in the Code-Behind:
private void DataGrid_CellEditEnding(object sender, DataGridCellEditEndingEventArgs e)
{
myDataGrid.CommitEdit();
}
If you don't understand anything then feel free to ask.
Update
If you are following the same approach:
In your DataGrid's Beginning edit event you can try:
private void DataGrid_BeginningEdit(object sender, DataGridBeginningEditEventArgs e)
{
if ((selectedRow as DataGridRow).Item.ToString() != "{NewItemPlaceholder}")
{
//Here you can add the code to add new item. I don't know how but you should figure out a way
}
}
Note: The code mentioned above is not tested.
I would also suggest you :
Not to use DataGrid. Instead use ListBox. Because, you are trying to add some data. At this time you never need sorting, searching and column-reordering fascilities. In such scenario, ListBox is useful as it is light-weight control than datagrid. I have a sample here: https://drive.google.com/open?id=0B5WyqSALui0bTXFGZWxQUWVRdkU
Is the problem that the UI is not being notified of changes to the objs collection? What I would do is try setting up whatever view model that contains objs to make objs an observable collection. I would also ensure that whatever objs is an observable collection of implements INotifyPropertyChanged and that properties p1 and p2 both fire OnPorpertyChanged when they are set.
public ObservableCollection<YourObject> objs
and
public class YourObject : INotifyPropertyChanged
{
protected void OnPropertyChanged(string Name)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(Name));
}
}
private string _p1;
public string p1
{
get { return _p1; }
set
{
if (_p1 != value)
{
_p1 = value;
OnPropertyChanged("p1");
}
}
}
private string _p2;
public string p2
{
get { return _p2; }
set
{
if (_p2 != value)
{
_p2 = value;
OnPropertyChanged("p2");
}
}
}
}
sorry if you think this is a duplication of another post, but I tried every possible solution out there and I can't make it work.
The question is a two parter, but it's about the same code, so I thought I can ask the question in the same thread.
I try to do order system in C#, wpf, vs2015 using mvvm without any (hard coded) couplings. There is two things I need to do. First is to fire an event which I need to capture in the ViewModel, and second, when the number of articles is over a certain level, the background of the listboxitem for that article should be green (otherwise white/grey)
For this I use a ListBox and some listBoxItems.
MainWindow.xaml (the part that matters)
<Window x:Class="Sequence_Application_2.GUI.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:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
xmlns:acb="clr-namespace:AttachedCommandBehavior;assembly=AttachedCommandBehavior"
mc:Ignorable="d"
....
<Window.DataContext>
<Grid Grid.Column="0" Margin="10">
<ListBox x:Name="LstViewFlows" SelectedItem="{Binding SelectedFlow.Name}" ItemsSource="{Binding Flows.Keys}" >
<ListBox.ItemContainerStyle>
<Style TargetType="{x:Type ListBoxItem}" >
<Style.Triggers>
<DataTrigger Binding="{Binding SelectedFlow.CanDeliver, UpdateSourceTrigger=PropertyChanged}" Value="true" >
<Setter Property="ListBoxItem.Background" Value="DarkGreen" />
<Setter Property="FontWeight" Value="Bold"/>
</DataTrigger>
</Style.Triggers>
</Style>
</ListBox.ItemContainerStyle>
<i:Interaction.Triggers>
<i:EventTrigger EventName="MouseLeftButtonDown">
<i:InvokeCommandAction Command="{Binding SetSelectedCommand}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
</ListBox>
</Grid>
Question 1)
I need to bind a command to a "MouseLeftButtonDown" event when I click on a listboxItem in a listbox. I tried the ACB-solution but can't get it to work. At last I tried the code above and I can't get it to trigger when I click on an item, but below the items, in the empty part of the listbox (not on a listboxitem), it tiggers as it should. Guess I need to rearange my xaml-file or something, but I tried for two days now I nothing seems to work.
The command is named "setSelectedCommand" and is implemented like this
internal class SetSelectedFlowCommand : ICommand
{
private FlowsViewModel _flowsViewModel;
public SetSelectedFlowCommand(FlowsViewModel flowsViewModel)
{
_flowsViewModel = flowsViewModel;
}
/// <summary>
///
/// </summary>
public event EventHandler CanExecuteChanged
{
add { CommandManager.RequerySuggested += value; }
remove { CommandManager.RequerySuggested -= value; }
}
public bool CanExecute(object parameter)
{
return true;
}
public void Execute(object parameter)
{
_flowsViewModel.SetSelectedFlow();
}
}
As I said, if I click on the ListBoxItem - nothing happends, but if i click in the ListBox - the command is fired (but nothing is "selected")
Question 2
As you see in the xaml above, I try to set the background color for a ListBoxitem, based on the value .CanDeliver in an object that is stored in a dictionary in the ViewModel. The variable Flow is the dictionary and SelectedFlow is supposed to be the flow that is selected.
This is an order system and CanDeliver is a variable that tells the operator/user if there is enough products to be delivered to the customer. If there are enough the listboxitem should be green, otherwise remain white/grey. Do you understand my question? Can I do it like this? Refering to an object inside a dictionary? (it's triggered by an INotifyPropertyChanged in the objects)
Hope you can help me because I have no more hair to pull from my head now ;-)
You don't need to use an event handler if all you want is to get the selectedItem. I have build an working example for you to show how to use binding only (MVVM) to achieve your requirements in your question:
C# (ViewModel):
using System;
using System.Collections.Generic;
using System.Windows;
using System.ComponentModel;
using System.Collections.ObjectModel;
namespace WpfApplication1
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
MyViewModel mvm = new MyViewModel()
{
Flows = new ObservableCollection<Flow>()
{
new Flow() { Name = "Flow1" },
new Flow() { Name = "Flow2" },
new Flow() { Name = "Flow3" , Amount=1},
new Flow() { Name = "Flow4" }
}
};
this.DataContext = mvm;
}
}
public class MyViewModel : ObservableObject
{
private Flow _selectedflow;
public ObservableCollection<Flow> Flows
{
get;
set;
}
public Flow SelectedFlow
{
get { return _selectedflow; }
set
{
if (value != _selectedflow)
{
_selectedflow = value;
RaisePropertyChanged("SelectedFlow");
}
}
}
}
public class Flow : ObservableObject
{
private string _name;
private int _amount;
public string Name
{
get { return _name; }
set
{
if (value != _name)
{
_name = value;
RaisePropertyChanged("Name");
}
}
}
public bool CanDeliver
{
get
{
return Amount > 0;
}
}
public int Amount
{
get { return _amount; }
set
{
if (value != _amount)
{
_amount = value;
RaisePropertyChanged("Amount");
RaisePropertyChanged("CanDeliver");
}
}
}
}
public class ObservableObject : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged(PropertyChangedEventArgs e)
{
var handler = this.PropertyChanged;
if (handler != null)
{
handler(this, e);
}
}
protected void RaisePropertyChanged(String propertyName)
{
OnPropertyChanged(new PropertyChangedEventArgs(propertyName));
}
}
}
XAML:
<Window x:Class="WpfApplication1.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="300" Width="350">
<Grid>
<StackPanel Orientation="Vertical">
<ListBox SelectedItem="{Binding SelectedFlow}" ItemsSource="{Binding Flows}" DisplayMemberPath="Name">
<ListBox.ItemContainerStyle>
<Style TargetType="{x:Type ListBoxItem}" >
<Style.Triggers>
<DataTrigger Binding="{Binding CanDeliver, UpdateSourceTrigger=PropertyChanged}" Value="true" >
<Setter Property="Background" Value="DarkGreen" />
<Setter Property="FontWeight" Value="Bold"/>
</DataTrigger>
</Style.Triggers>
</Style>
</ListBox.ItemContainerStyle>
</ListBox>
<TextBlock Text="{Binding SelectedFlow.Name}"/>
</StackPanel>
</Grid>
</Window>
Result: You can see the Flow item with CanDeliver = True (Amount>0) has a Green background. And the TextBlock is showing the SelectedFlow.
I have a WPF Application and have populated a DataGrid with values from a SQL query. I have added a DataGridCheckBoxColumn and button to the window. When the button is clicked I want to grab the data from the first selected row and insert into a text box or store as a variable. Please explain the answer in a way that someone who is new to c# developing would understand so I can learn rather than copy and paste.
Here is my XAML:
<Window x:Class="WpfApplication7.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="NAME SELECT"
SizeToContent="WidthAndHeight"
>
<Grid >
<Grid.ColumnDefinitions>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<DataGrid x:Name="selectDataGrid" HorizontalAlignment="Left" VerticalAlignment="Top" Height="92" Width="288" AutoGenerateColumns="False">
<Style TargetType="{x:Type DataGridRow}" >
</Style>
<DataGrid.Columns>
<DataGridCheckBoxColumn x:Name="dgCheckBox" Header="Select" Width="45" Binding="{Binding IsChecked}"/>
<DataGridTextColumn Header="FIRST NAME" Width="125" Binding="{Binding FNAME}"/>
<DataGridTextColumn Header="LAST NAME" Width="125" Binding="{Binding LNAME}"/>
</DataGrid.Columns>
</DataGrid>
<Button Content="Update Fields" HorizontalAlignment="Left" Margin="193,97,0,0" VerticalAlignment="Top" Width="95" Click="Button_Click"/>
</Grid>
Here is my c# behind:
private void Button_Click(object sender, RoutedEventArgs e)
{
for (int i = 0; i < selectDataGrid.Items.Count -1; i++)
{
DataGridRow cell = GetRow(i);
CheckBox tb = cell.value as CheckBox;
System.Windows.MessageBox.Show(tb.IsChecked.ToString());
}
}
public DataGridRow GetRow(int index)
{
DataGridRow row = (DataGridRow)selectDataGrid.ItemContainerGenerator.ContainerFromIndex(index);
if (row == null)
{
selectDataGrid.UpdateLayout();
selectDataGrid.ScrollIntoView(selectDataGrid.Items[index]);
row = (DataGridRow)selectDataGrid.ItemContainerGenerator.ContainerFromIndex(index);
}
return row;
}
If I could get help to the point of displaying the selected result to a message box I could go from there. I'm only interested in the FIRST instance of a selected row. So if multiple rows are selected I'm only interested in the first row selected.
I have read all the solutions to anything that had my keywords and I cannot find anything that fits my specific need of only wanting the first row. I'm not experienced enough to be able to make leaps and jumps or to alter code for something else to work for me. If you are going to link me to another solution please explain what I would need to change on my code, or what parts I would need from the solution. Ideally working code in a solution is what would be best.
I can suggest you the next solution; data grid has readonly dependency property (link to dependency property: msdn explanation and WPF Dependency Property, CodeProject explanation) which cannot be accessed from XAML but you can access this in code behind or behavior code (link to behavior: good behavior explanation and anothere one good explanation). If you access this property and get the first member in that collection you will have the first selected item in your hands. But I frankly advice you to learn the MVVM (link to MVVM: CodeProject explanation and more) pattern. The MVVM pattern is the a correct way to work with the WPF. Solution:
1. XAML code:
<Window x:Class="SimpleDataGrid.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:simpleDataGrid="clr-namespace:SimpleDataGrid"
Title="MainWindow" Height="350" Width="525">
<Grid >
<Grid.RowDefinitions>
<RowDefinition Height="*"></RowDefinition>
<RowDefinition Height="Auto"></RowDefinition>
</Grid.RowDefinitions>
<Grid.DataContext>
<simpleDataGrid:GridViewModel/>
</Grid.DataContext>
<DataGrid x:Name="SelectDataGrid" ItemsSource="{Binding Persons}" HorizontalAlignment="Left" VerticalAlignment="Top" AutoGenerateColumns="False">
<DataGrid.Resources>
<Style TargetType="{x:Type DataGridRow}" >
</Style>
</DataGrid.Resources>
<DataGrid.Columns>
<DataGridCheckBoxColumn x:Name="dgCheckBox" Header="Select" Width="45" Binding="{Binding IsChecked}"/>
<DataGridTextColumn Header="FIRST NAME" Width="125" Binding="{Binding FNAME}"/>
<DataGridTextColumn Header="LAST NAME" Width="125" Binding="{Binding LNAME}"/>
</DataGrid.Columns>
</DataGrid>
<Button Grid.Row="1" Content="Update Fields" HorizontalAlignment="Left" Margin="5" VerticalAlignment="Top" Width="95" Click="Button_Click"/>
</Grid></Window>
2. View Model code:
public class GridViewModel:BaseObservableObject
{
public GridViewModel()
{
var l = new List<Person>
{
new Person {FNAME = "John", LNAME = "W"},
new Person {FNAME = "George", LNAME = "R"},
new Person {FNAME = "Jimmy", LNAME = "B"},
new Person {FNAME = "Marry", LNAME = "B"},
new Person {FNAME = "Ayalot", LNAME = "A"},
};
Persons = new ObservableCollection<Person>(l);
}
public ObservableCollection<Person> Persons { get; set; }
}
3. Code behind and Person model:
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
private void Button_Click(object sender, RoutedEventArgs e)
{
var dataGrid = SelectDataGrid;
var selected = dataGrid.SelectedItems.Cast<Person>().ToList();
var mostFirst = selected.FirstOrDefault();
}
}
public class Person : BaseObservableObject
{
private string _lName;
private string _fName;
private bool _checked;
public bool IsChecked
{
get { return _checked; }
set
{
_checked = value;
OnPropertyChanged();
}
}
public string LNAME
{
get { return _lName; }
set
{
_lName = value;
OnPropertyChanged();
}
}
public string FNAME
{
get { return _fName; }
set
{
_fName = value;
OnPropertyChanged();
}
}
}
4. BaseObservableObject code (simple implementation of INotifyPropertyChanged):
public class BaseObservableObject : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
var handler = PropertyChanged;
if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
}
protected virtual void OnPropertyChanged<T>(Expression<Func<T>> raiser)
{
var propName = ((MemberExpression)raiser.Body).Member.Name;
OnPropertyChanged(propName);
}
protected bool Set<T>(ref T field, T value, [CallerMemberName] string name = null)
{
if (!EqualityComparer<T>.Default.Equals(field, value))
{
field = value;
OnPropertyChanged(name);
return true;
}
return false;
}
}
I hope it will help you.
Regards.
the XAML of my window:
<ListView Grid.Row="0" Name="files">
<ListView.Resources>
<DataTemplate x:Key="CheckboxTemplate">
<CheckBox IsChecked="{Binding Save, Mode=TwoWay}" />
</DataTemplate>
</ListView.Resources>
<ListView.View>
<GridView AllowsColumnReorder="False">
<GridViewColumn Header=" " Width="30" CellTemplate="{StaticResource CheckboxTemplate}" />
<GridViewColumn Header="Datei" DisplayMemberBinding="{Binding File}"/>
</GridView>
</ListView.View>
</ListView>
the constructor of my Window:
IEnumerable<SaveItem> sil = sdl.Select(d => new SaveItem() { Save = true, Document = d });
files.ItemsSource = sil;
and the datastructure i want to display:
public class SaveItem : INotifyPropertyChanged
{
private bool save;
public bool Save
{
get { return this.save; }
set
{
if (value != this.save)
{
this.save = value;
NotifyPropertyChanged("Save");
}
}
}
private void NotifyPropertyChanged(String info)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(info));
}
}
public StandardDocument Document { get; set; }
public string File { get { return Document.Editor.File; } }
#region INotifyPropertyChanged Member
public event PropertyChangedEventHandler PropertyChanged;
#endregion
}
i call the window. The window appears. I uncheck a checkbox of an item of the listview. i click a button. in its event-handler i read out the itemssource of the listview and ... the Save-Property of the Unchecked Item is (in its source) still true!
where is my mistake? why does my sources not get updated if i check/uncheck a checkbox?
You have not set your data context. If you are all in the same class - put something like this in your constructor of the window.
DataContext = this;
I think you need to set the DataContext to the code behind and then for clarity bind to the path.
XAML to set the Window DataContext
DataContext="{Binding RelativeSource={RelativeSource Self}}"
try converting IEnumerable to list..
it is not suggested to use IEnumerable as item source particularly when item source is evaluated using Linq
List<SaveItem> sil = sdl.Select(d => new SaveItem() { Save = true, Document = d }).ToList<SaveItem>();
files.ItemsSource = sil;