We Keep Coding

Select first item in ListView by default, MVVM, C#

I am writing some programm where is possible to select device and later configure it. I implemented ListView where all device are listed. I like that first device is selected by default. How to do that? I try several solution found on StackOverflow and over Google but without luck.
Here is my code in XAML:
<ListView Name="lvdevices" Grid.Row="1" Margin="2" ItemsSource="{Binding devicelist}" SelectionMode="Single" SelectedItem="{Binding SelectedDevice}" DataContext="{Binding }">
<ListView.View>
<GridView x:Name="gridDevices">
<GridViewColumn>
<GridViewColumn.CellTemplate>
<DataTemplate>
<CheckBox Tag="{Binding ID}" IsChecked="{Binding RelativeSource={RelativeSource AncestorType={x:Type ListViewItem}}, Path=IsSelected}"/>
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>
<GridViewColumn x:Name="DeviceId" Header="DeviceId" DisplayMemberBinding="{Binding DeviceId}" Width="50"/>
<GridViewColumn x:Name="NameId" Header="NameId" DisplayMemberBinding="{Binding NameId}" Width="100"/>
<GridViewColumn x:Name="ManufacturerId" Header="ManufacturerId" DisplayMemberBinding="{Binding ManufacturerId}" Width="150"/>
</GridView>
</ListView.View>
</ListView>
I dont know how to implement that first item is selected by default when is connected. It is also possibility that no device will found, what then? Please for help! If and question please ask.

When you populate your devicelist, you can set the SelectedDevice to be the first item in the device list, or null if there is nothing in the list.
using System.Linq;
...
SelectedDevice = devicelist.FirstOrDefault();
Assuming that SelectedDevice implements INotifyPropertyChanged, this should then select the first item on your view.

In your ViewModel, you just need to set your SelectedDevice to the first item (and of course trigger a OnPropertyChanged)

How to access checkboxes in a List view one by one

I want to check all text boxes on the basis of if the check box is checked. But I don't know how to access all check boxes one by one? I bound it with ApprovalStatus which is of boolean type. Can any one help me to have code in C#?
<CheckBox Content="Check All" Height="16" HorizontalAlignment="Left" Margin="9,193,0,0" Name="Tab2CheckAll" VerticalAlignment="Top" Width="77" Click="Tab2CheckAll_Click"/>
<ListView Height="213" HorizontalAlignment="Left" Margin="9,215,0,0" Name="Tab2EmployeeEffortList" VerticalAlignment="Top" Width="771" AllowDrop="True" IsTextSearchEnabled="True">
<ListView.View>
<GridView>
<GridViewColumn Header="Approved" Width="100">
<GridViewColumn.CellTemplate>
<DataTemplate>
<CheckBox CommandParameter="{Binding}" IsChecked="{Binding ApprovalStatus}"/>
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>
</GridView>
</ListView.View>
</ListView>

You need not to access individual checkBoxes. CheckBox is already bounded to property set that instead.
Loop over ItemsSource of ListView and set ApprovalStatus to true for all items in the collection. As long as your underlying source class is implementing INotifyPropertyChanged, it will work fine.

Binding combobox in DataTemplate to a different ItemSource

I have 2 ObservableCollection lists, which we can call A and B, then I have a GridView that I want to bind to list A and a ComboBox INSIDE that GridView, that I want to bind to list B.
I've set the ItemsSource property of the GridView by code: gridview.ItemsSource=A (and it works!). About the ComboBox its instance it is not available by code, I suppose because its definition it is enclosed between the DataTemplate tags; so I wonder how to bind the combo to list B, either by code or by XAML.
Follows the XAML code:
<ListView Grid.Row="0" Grid.Column="1" HorizontalAlignment="Stretch" Margin="0,0,0,0" Name="lstReplacements" VerticalAlignment="Stretch">
<ListView.View>
<GridView>
<GridViewColumn HeaderContainerStyle="{StaticResource MyHeaderStyle}" Header="Wrong text" DisplayMemberBinding="{Binding Word}"/>
<GridViewColumn HeaderContainerStyle="{StaticResource MyHeaderStyle}" Header="Replacement" Width="60" DisplayMemberBinding="{Binding Replacement}" />
<GridViewColumn HeaderContainerStyle="{StaticResource MyHeaderStyle}" Header="Type" Width="30">
<GridViewColumn.CellTemplate>
<DataTemplate>
<ComboBox ItemsSource="{??????}" DisplayMemberPath="??????" Grid.Row="1" Grid.Column="0" Name="cmbCorrectionType" Width="75" />
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>
</GridView>
</ListView.View>
</ListView>
Thanks in advance for the support!
Chris

I assume this control is in UserControl and you have set DataContext of that UserControl to the class instance where your both collections CollectionA and CollectionB resides.
You can then bind using RelativeSource:
<ComboBox ItemsSource="{Binding DataContext.CollectionB,
RelativeSource={RelativeSource Mode=FindAncestor,
AncestorType=UserControl}}"/>
Also you can set DataContext of ListView to the class instance and all you need to do is change AncestorType to ListView in place of UserControl in above binding.

Checkbox in gridviewcolumn(header)

I am using a listview (gridview/gridviewcolumn)
where the first column
contains only checkboxes for each row. Instead of adding a select all button I want
to add a Checkbox into the header of the first column.
Selecting the checkbox in the header will select
all other checkboxes and vice versa.
How can I do that in xaml?
Update:
This is the important part of my xaml code. (simplified)
<ListView ItemSource="...">
<ListView.View>
<GridView>
<GridViewColumn>
<GridViewColumn.CellTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<CheckBox IsChecked="{Binding IsSelected}" />
</StackPanel>
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>
</GridView>
</ListView.View>
</ListView>

To have a checkbox on top of GridViewColumn you can do something like this
<GridViewColumn>
<GridViewColumn.Header>
<CheckBox/>
</GridViewColumn.Header>
<GridViewColumn.CellTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<CheckBox IsChecked="{Binding IsSelected}" />
</StackPanel>
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>
Now you can handle the check event and in the code you can iterate through your itemsSource and change values or if you are following MVVM you can bind property with checkbox so that whenever check is changed you will be notified through INotifyPropertyChanged. Once you find out through binding that check has changed, again you can change your itemssource accordingly

How to bind to 2 different members in a class in WPF?

I have a class like:
class EditorViewModel
{
public ObservableCollection<Effect> AllEffects;
public bool HasPermissions;
}
But the problem is, when I am trying to bind AllEffects to ListView, then I can't bind anything to HasPermissions because the binding scope is limited to AllEffects, not EditorViewModel.
I tried this but it doesn't work:
<ListView ItemsSource="{Binding EditorViewModel}">
...
<GridViewColumn Width="Auto" Header="Name">
<GridViewColumn.CellTemplate>
<DataTemplate>
<TextBlock Text="{Binding AllEffects.Name}"/>
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>
<GridViewColumn Width="Auto" Header="Type">
<GridViewColumn.CellTemplate>
<DataTemplate>
<TextBlock Text="{Binding AllEffects.Type}"/>
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>
If I set the ItemsSource to EditorViewModel and get rid of AllEffects, it works. But then I don't know how to access HasPermissions through binding:
<GridViewColumn Width="50" Header="Override">
<GridViewColumn.CellTemplate>
<DataTemplate>
<CheckBox Margin="0"
HorizontalAlignment="Center"
IsEnabled="{Binding HasPermission}"/>
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>

As I updated my answer on this question to include, you can bind the ListView to the AllEffects property of your ViewModel and then refer to a different property of the ViewModel using a relative binding. So assuming your ListView is contained in a Window whose DataContext is an EditorViewModel, and the ListView's ItemsSource is AllEvents, you can still reference HasPermission like so:
<CheckBox Margin="0"
HorizontalAlignment="Center"
IsEnabled="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}}, Path=DataContext.HasPermission}"/>
That somewhat clunky notation will find the nearest parent element to the CheckBox in the visual tree that is of type Window, and bind to its DataContext property to find HasPermission.

A classic trick is to use ViewModelLocator, see:
MVVM Light - using ViewModelLocator - properties hit multiple times
also, for a more quick-and-dirty solution, you can use the following Binding:
{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=ListView}, Path=DataContext.HasPermissions}
Note that this would only work on WPF and not in SL, since SL doesn't support this syntax of RelativeSource.