I have Items from a certain source (populated from somewhere else):
public class ItemsFromSource{
public ItemsFromSource(string name){
this.SourceName = name;
Items = new List<IItem>();
}
public string SourceName;
public List<IItem> Items;
}
Now in MyClass I have Items from several sources (populated from somewhere else):
public class MyClass{
public MyClass(){
}
public List<ItemsFromSource> BunchOfItems;
}
Is there a simple way to iterate through all Items in all ItemsFromSources in BunchOfItems in one go? ie, something like:
foreach(IItem i in BunchOfItems.AllItems()){
// do something with i
}
instead of doing
foreach(ItemsFromSource ifs in BunchOffItems){
foreach(IItem i in ifs){
//do something with i
}
}
那么,您可以使用linq函数SelectMany进行flatmap (创建子列表并将它们压缩成一个)的值:
foreach(var i in BunchOfItems.SelectMany(k => k.Items)) {}
You can use SelectMany
:
foreach(IItem i in BunchOffItems.SelectMany(s => s.Items)){
// do something with i
}
You could make a function to do that for you.
Enumerable<T> magic(List<List<T>> lists) {
foreach (List<T> list in lists) {
foreach (T item in list) {
yield return item;
}
}
}
Then you just do:
List<List<int>> integers = ...;
foreach (int i in magic(integers)) {
...
}
Also, I think PowerCollections will have something for that out of the box.
//Used to flatten hierarchical lists
public static IEnumerable<T> Flatten<T>(this IEnumerable<T> items, Func<T, IEnumerable<T>> childSelector)
{
if (items == null) return Enumerable.Empty<T>();
return items.Concat(items.SelectMany(i => childSelector(i).Flatten(childSelector)));
}
I think this will work for what you want to do. Cheers.
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