MV485_v125/MV485/helper/MultiSelectComboBox.xaml.cs

using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Windows;
using System.Windows.Controls;

namespace MV485.helper
{
    public partial class MultiSelectComboBox : UserControl, INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;
        protected void OnPropertyChanged(string propertyName)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }

        public ObservableCollection<SelectableItem> Items { get; set; } = new ObservableCollection<SelectableItem>();

        private string _selectedText = "请选择...";
        //public string SelectedText
        //{
        //    get => _selectedText;
        //    set
        //    {
        //        _selectedText = value;
        //        comboBox.Text = value; // 确保 UI 显示更新
        //    }
        //}
        public string SelectedText
        {
            get => _selectedText;
            set
            {
                if (_selectedText != value)
                {
                    _selectedText = value;
                    OnPropertyChanged(nameof(SelectedText)); // 触发UI更新
                }
            }
        }

        public MultiSelectComboBox()
        {
            InitializeComponent();
            comboBox.ItemsSource = Items;
        }

        public void SetItems(string[] itemNames,bool selectAll = true)
        {
            Items.Clear();
            if (selectAll)
            {
                Items.Add(new SelectableItem { Name = "全选", IsSelected = false });
            }

            foreach (var name in itemNames)
            {
                Items.Add(new SelectableItem { Name = name, IsSelected = false });
            }

            //comboBox.ItemsSource = null;
            //comboBox.ItemsSource = Items;
            comboBox.ItemsSource = Items;
            UpdateSelectedText();
        }

        private void CheckBox_Changed(object sender, RoutedEventArgs e)
        {
            CheckBox checkBox = sender as CheckBox;
            SelectableItem selectedItem = checkBox.DataContext as SelectableItem;

            if (selectedItem.Name == "全选")
            {
                bool isAllSelected = selectedItem.IsSelected;
                foreach (var item in Items.Skip(1))
                {
                    item.IsSelected = isAllSelected;
                }
            }
            else
            {
                if (!selectedItem.IsSelected)
                {
                    Items[0].IsSelected = false;
                }
                else if (Items.Skip(1).All(i => i.IsSelected))
                {
                    Items[0].IsSelected = true;
                }
            }

            UpdateSelectedText();
        }

        //private void UpdateSelectedText()
        //{
        //    var selectedItems = Items.Skip(1).Where(i => i.IsSelected).Select(i => i.Name);
        //    SelectedText = selectedItems.Any() ? string.Join(", ", selectedItems) : "请选择...";
        //}

        private void UpdateSelectedText()
        {
            //var selectedItems = Items.Where(i => i.IsSelected).Select(i => i.Name).ToList();
            var selectedItems = Items
                .Where(i => i.IsSelected && i.Name != "全选")
                .Select(i => i.Name)
                .ToList();

            SelectedText = selectedItems.Any() ? string.Join(", ", selectedItems) : "请选择...";
            OnPropertyChanged(nameof(SelectedText));
        }

        public string GetSelectedItems()
        {
            //return string.Join(", ", Items.Skip(1).Where(i => i.IsSelected).Select(i => i.Name));
            return string.Join(", ", Items.Where(i => i.IsSelected && i.Name != "全选").Select(i => i.Name));
        }

        public void SetSelectedValues(string values)
        {
            if (string.IsNullOrWhiteSpace(values)) return;

            // 解析字符串，按逗号分割
            var selectedList = values.Split(',').Select(v => v.Trim()).ToList();

            // 遍历 Items，匹配 Name，更新 IsSelected
            foreach (var item in Items)
            {
                item.IsSelected = selectedList.Contains(item.Name);
            }

            // 更新显示的文本
            UpdateSelectedText();
        }

        private void ComboBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            comboBox.SelectedItem = null;            
        }

        private void ComboBoxItem_PreviewMouseLeftButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
        {
            if (sender is ComboBoxItem item && item.DataContext is SelectableItem data)
            {
                data.IsSelected = !data.IsSelected;  // 切换选中状态
                UpdateSelectedText();                // 更新显示文字

                // 防止 ComboBox 默认选中行为（不然还是会出现“MV485.helper.SelectableItem”）
                comboBox.SelectedItem = null;
                e.Handled = true;
            }
        }

        private void ComboBox_DropDownClosed(object sender, System.EventArgs e)
        {
            // 恢复文本显示
            UpdateSelectedText();
        }


        //--------------------------------------------------------------------------------
    }

    public class SelectableItem : System.ComponentModel.INotifyPropertyChanged
    {
        private bool _isSelected;
        public string Name { get; set; }
        public bool IsSelected
        {
            get => _isSelected;
            set
            {
                _isSelected = value;
                PropertyChanged?.Invoke(this, new System.ComponentModel.PropertyChangedEventArgs(nameof(IsSelected)));
            }
        }

        public event System.ComponentModel.PropertyChangedEventHandler PropertyChanged;
    }
}