List <string>如何成为AutoCompleteStringCollection

Question

我有列表,我想将其转换为autoCompleteStringCollection ..我不想使用foreach.

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

注意user.GetNameUsers()是列表.

代码不起作用,它变为null.

谢谢

Answer 1

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

如果您经常需要这个,可以编写扩展方法:

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;
    }
}

用法:

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