How List <string> becomes AutoCompleteStringCollection

Question

I have a list, I want to convert it to autoCompleteStringCollection .. And I do not want to use foreach.

_textbox.AutoCompleteMode = AutoCompleteMode.Append; _textbox.AutoCompleteSource = AutoCompleteSource.CustomSource; _textbox.AutoCompleteCustomSource = user.GetNameUsers() as AutoCompleteStringCollection; 

Note: user.GetNameUsers () is a list.

The code does not work, it becomes zero.

thanks

Answer 1

 _textbox.AutoCompleteMode = AutoCompleteMode.Append; _textbox.AutoCompleteSource = AutoCompleteSource.CustomSource; var autoComplete = new AutoCompleteStringCollection(); autoComplete.AddRange(user.GetNameUsers().ToArray()); _textbox.AutoCompleteCustomSource = autoComplete; 

If you need this often, you can write an extension method:

 public static class EnumerableExtensionsEx { public static AutoCompleteStringCollection ToAutoCompleteStringCollection( this IEnumerable<string> enumerable) { if(enumerable == null) throw new ArgumentNullException("enumerable"); var autoComplete = new AutoCompleteStringCollection(); foreach(var item in enumerable) autoComplete.Add(item); return autoComplete; } } 

Using:

 _textbox.AutoCompleteCustomSource = user.GetUsers().ToAutoCompleteStringCollection(); 

Answer 2

By checking the documentation for AutoCompleteStringCollection , and in particular the constructor, I see that there is no constructor that accepts a List .

Therefore, you have 2 options.

1) Use AddRange to add all list items to a new instance of AutoCompleteStringCollection

 var acsc= new AutoCompleteStringCollection(); acsc.AddRange(user.GetNameUsers().ToArray()); 

2) Inherit a new class that adds the constructor you need, and call the same code as above.

 public class MyAutoCompleteStringCollection : AutoCompleteStringCollection { public MyAutoCompleteStringCollection(IEnumerable items) { this.AddRange(items.ToArray()) } } 

So you can use

 _textbox.AutoCompleteCustomSource = new MyAutoCompleteStringCollection (user.GetNameUsers()); 

Personally, I would go with option 1 at the moment.