Just raise the NotifyPropertyChanged
event for the property you want to validate or if you are in .NET 4.5 or Silverlight 4 use the INotityDataErrorInfo.
Force IDataErrorInfo validation
-
29-11-2021 - |
Question
I have two controls on some panel: textbox and combobox:
<TextBox Text="{Binding ShapeName, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=True}" />
<ComboBox SelectedItem="{Binding ActiveStageViewModel, Mode=OneWayToSource, UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=True}" />
I need to force idataerrorinfo validation for textbox, when I select something on combobox. How to do that?
The code from viewmodel:
string IDataErrorInfo.this[string propertyName]
{
get
{
var error = string.Empty;
if (propertyName == Expression.GetPropertyName(() => ActiveStageViewModel))
{
// TODO: Add functionality to force ShapeName property validation
return error;
}
if (propertyName == Expression.GetPropertyName(() => ShapeName))
{
error = ValidateShapeName();
}
TooltipMessage = error;
return error;
}
}
Solution
OTHER TIPS
Worth remembering also that you can raise NotifyPropertyChanged with String.Empty property. This will force validation of all properties at that level. Can be useful at times.
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