// Shows how view can get value of a specified field of any ModelA.
internal string TextA(IModelA ia)
{
var a = (ModelA)ia;
// TBD: Or maybe pass an empty string when missing.
return(a != null ? a.TextA : null);
}
public IModelA LoadA(int id)
{
IModelA modelA = _modelFactory.CreateModelA();
// fill modelA with data from database
return(modelA);
}
// Return "true" if succeeds.
internal bool SetCurrentModelAByIndex(int index)
{
IModelA desiredA = GetOneModelA(index);
if (desiredA != null)
{
CurrentA = desiredA;
return(true);
}
else
{
return(false);
}
}
// --- represents a method used within view's workflow. ---
public void SomeMethod()
{
// E.g., based on user selection, make a specified ModelA be "current".
// (In practice, it would take a more complex scenario for view to want to hold an IModelA.)
// (In this simple case, View could hold an index, call SetCurrentModelAByIndex, not need an IModelA object.)
IModelA desiredA = vm.GetOneModelA(1);
if (desiredA != null)
{
vm.CurrentA = desiredA;
}
else
{
// ... message to user ...
}
}
internal void SetCurrentModelA(IModelA desiredA)
{
// By design, IModelA always holds a ModelA (or null), so this cast always succeeds.
_a = (ModelA)desiredA;
}
