BindingGroup::GetValue Method (Object^, String^)
Returns the proposed value for the specified property and item.
Assembly: PresentationFramework (in PresentationFramework.dll)
Parameters
- item
-
Type:
System::Object^
The object that contains the specified property.
- propertyName
-
Type:
System::String^
The property whose proposed value to get.
| Exception | Condition |
|---|---|
| InvalidOperationException | There is not a binding for the specified item and property. |
| ValueUnavailableException | The value of the specified property is not available, due to a conversion error or because an earlier validation rule failed. |
Use this method in the ValidationRule::Validate method to get the value to be committed to the source. The type of the return value depends on the stage at which the ValidationRule occurs. For example, if a TextBox is data bound to a property of type integer and the ValidationRule that calls GetValue(Object^, String^) has its ValidationStep set to RawProposedValue, the method returns a string. If the ValidationRule has its ValidationStep set to ConvertedProposedValue, the method returns whatever type that is returned by the binding's converter. In this example, GetValue(Object^, String^) usually returns an integer.
The following example is part of an application that prompts the user to enter multiple customers and assign a sales representative to each customer. The application checks that the sales representative and the customer belong to the same region. The example shows the Validate method, which uses the GetValue(Object^, String^) method to get values that the customer entered.
Available since 3.0