Requirement:
Need to display an error message when the user types a forlder name that doesn't exist as shown below:Problem: I am able to display the UI but not able to call a method in the view model when the user clicks on the button "CreateNew"
View Model Code:
public string this[string columnName]
{
get { return "The entered folder name doesn't exist."; }
}
RelayCommand createNewFolder;
public RelayCommand CreateNewFolder
{
get
{
if (createNewFolder == null)
createNewFolder = new RelayCommand(param => this.OnCreateNewFolder());
return createNewFolder;
}
}
public void OnCreateNewFolder()
{
MessageBox.Show("CreateNewFolder");
}
RelayCommand.cs can be downloaded at: http://code.msdn.microsoft.com/Project/Download/FileDownload.aspx?ProjectName=mag200902MVVM&DownloadId=4357
Xaml Code:
<Window.Resources>
<ControlTemplate x:Key="validationTemplate">
<DockPanel LastChildFill="True">
<Border Margin="5,5,0,0" DockPanel.Dock="Bottom" Background="Red">
<StackPanel>
<TextBlock Name="ErrorText" Foreground="White" Background="Red"
FontSize="12" Padding="2" FontFamily="Trebuchet MS"
TextWrapping="Wrap"
Text="{Binding [0].ErrorContent}" ></TextBlock>
<StackPanel Margin="0" Orientation="Horizontal">
<Button Content="Create New" Command="{Binding Path=CreateNewFolder}" Margin="10" Padding="5"></Button>
<Button Content="Cancel" Margin="10" Padding="5" ></Button>
</StackPanel>
</StackPanel>
</Border>
<AdornedElementPlaceholder Name="ErrorTextBox" />
</DockPanel>
</ControlTemplate>
<Style x:Key="ValidationStyle" TargetType="{x:Type ComboBox}">
<Style.Triggers>
<Trigger Property="Validation.HasError" Value="True">
<Setter Property="BorderBrush" Value="Red" />
<Setter Property="BitmapEffect">
<Setter.Value>
<BitmapEffectGroup>
<OuterGlowBitmapEffect GlowColor="Red" GlowSize="3" Noise="0.6"></OuterGlowBitmapEffect>
</BitmapEffectGroup>
</Setter.Value>
</Setter>
<Set开发者_运维问答ter Property="DataContext"
Value="{Binding RelativeSource={x:Static RelativeSource.Self},Path=DataContext}">
</Setter>
</Trigger>
</Style.Triggers>
</Style>
</Window.Resources>
<Grid>
<AdornerDecorator >
<ComboBox IsEditable="True" FontSize="11" Margin="10" Width="250"
VerticalAlignment="Center"
Text="{Binding Path=StrText, ValidatesOnDataErrors=True, UpdateSourceTrigger=PropertyChanged}"
Validation.ErrorTemplate="{StaticResource validationTemplate}"
Style="{StaticResource ValidationStyle}"></ComboBox>
</AdornerDecorator>
</Grid>
Please note that i set the DataContext property in the style:
<Setter Property="DataContext" Value="{Binding RelativeSource={x:Static
RelativeSource.Self},Path=DataContext}">
</Setter>
Please let me know how to bind the method to a button in the validation template. You could reference the DataContext for the AdornerDecorators Child in the Binding. I think something like this will work
<Button Content="Create New"
Command="{Binding RelativeSource={RelativeSource AncestorType={x:Type AdornerDecorator}},
Path=Child.DataContext.CreateNewFolder}"
Margin="10" Padding="5"></Button>
This line looks suspicious:
createNewFolder = new RelayCommand(param => this.OnCreateNewFolder());
Maybe you should replace it by:
createNewFolder = new RelayCommand(OnCreateNewFolder);
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