WPF 资源没有反映后面代码的变化

Question

In MainWindow...

Ingredients allIngredients = this.FindResource("allIngredients") as Ingredients;
allIngredients = (Ingredients)reader.Deserialize(file);
foreach (Ingredient i in allIngredients)
{
  ingredientListBox.Items.Add(i);
}

The XML deserializes into my object fine, the listbox populates with the items just fine. However, I also need to be able to access allIngredients from another method inside MainWindow, and when I do another FindResource in that method, all I have is an empty list. I've done testing with other FindResource situations, and in those situations the resource reflected any changes made, no matter what method I changed them from. This seems to only happen when I deserialize into the resource. The object becomes populated and works as expected, but only in the method that I deserialize in. What could I be doing wrong?

Answer 1

This happens because you don't change the instance that's saved in the resource dictionary, but instead create a new object (by deserializing) and don't save it into the dictionary.

Here's how you should do it (note you don't even need to read from the dictionary):

var allIngredients = (Ingredients)reader.Deserialize(file);
element.Resources["allIngredients"] = allIngredients;
foreach (Ingredient i in allIngredients)
{
  ingredientListBox.Items.Add(i);
}

This assumes element is where the resource is found (possibly be this in your code.)