wpf ObservableCollection篩選功能

viewmodel中定義原始資料及篩選後的資料，篩選後的資料型別為ICollectionView

//原始資料列表
public ObservableCollection<SchoolOutDto> SchoolList { get; set; }

/// <summary>
/// 篩選資料後的列表
/// </summary>
public ICollectionView FilterSchoolList { get; set; }

//輸入框繫結的值
public string SchoolText
{
    get => schoolText; set
    {
        schoolText = value;
        //根據篩選的名稱重新整理列表
        FilterSchoolList.Refresh();
    }
}

在原始資料獲取到資料後繫結篩選後的資料

FilterSchoolList = CollectionViewSource.GetDefaultView(SchoolList);
FilterSchoolList.Filter = Filter;  //此處的Filter為一個回撥函式

Filter

private bool Filter(object obj)
{
    var m = obj as SchoolOutDto;
    if (string.IsNullOrEmpty(SchoolText) )
    {
        return true;
    }

    //輸入框與選擇的列表一致時重置列表(此時為選擇了某條資料直接重置)
    if (SelectedSchool != null && SelectedSchool.schoolName==SchoolText)
    {
        return true;
    }

    if (m.schoolName.Contains(SchoolText))
    {
        return true;
    }
    return false;
}