使用CompositeCollection向ComboBox添加自定义值

// 创建CompositeCollection对象
CompositeCollection compositeCollection = new CompositeCollection();

// 创建自定义值的集合
List<string> customValues = new List<string>() { "Value1", "Value2", "Value3" };

// 创建CollectionContainer对象，并设置Items属性为自定义值的集合
CollectionContainer collectionContainer = new CollectionContainer();
collectionContainer.Collection = customValues;

// 将CollectionContainer对象添加到CompositeCollection的Items集合中
compositeCollection.Add(collectionContainer);

// 将CompositeCollection对象赋值给ComboBox的ItemsSource属性
comboBox.ItemsSource = compositeCollection;