c# - 将数据绑定(bind)到 Windows 窗体 TabControl

Question

我正在尝试我的第一个 Windows 窗体项目，之前完全基于 Web 并遇到了一些问题。我想将对象列表绑定(bind)到 TabControl 并让它创建选项卡，然后让数据绑定(bind)值可从每个选项卡的单击事件访问。

我要绑定(bind)的对象是

public class TreeNodeItem
{
    private NTree<string> node;

    public TreeNodeItem(NTree<string> node)
    {
        this.node = node;
    }

    public string Value
    {
        get { return this.node.data; }
    }
}

NTree 节点表示对象中的一个节点，该对象以树结构对数据进行建模。我想为列表中的每个对象创建一个选项卡，并将 Value 属性绑定(bind)到 Tab Text 属性。其他帖子提到绑定(bind)到控件的 ItemsSource 属性，但 Visual Studio 没有给我这个属性。

任何帮助将不胜感激。

干杯

斯图尔特

Answer 1

好吧，我不知道绑定(bind) 是必须的。尽管我从未见过在 Windows 窗体应用程序中执行过这样的操作，但我决定创建一个类来为我们执行此操作。

它使用 ObservableCollection<T>跟踪列表中的对象/属性是否已更改。

    public class ObservableList<T> : ObservableCollection<T>
    {
        public ObservableList() : base()
        {
            CollectionChanged += new NotifyCollectionChangedEventHandler(nObservableCollection_CollectionChanged);
        }

        public event PropertyChangedEventHandler OnPropertyChanged;

        void nObservableCollection_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
        {
            if (OnPropertyChanged != null)
            {
                OnPropertyChanged(new object[] { e.OldItems, e.NewItems }, null); // Call method to let it change the tabpages
            }
        }
    }

现在，我们必须创建一个辅助类来帮助我们跟踪:

    public class TabControlBind
    {
        public TabControlBind(TabControl tabControl)
        {
            // Create a new TabPageCollection and bind it to our tabcontrol
            this._tabPages = new TabControl.TabPageCollection(tabControl);
        }

        // Fields
        private ObservableList<TreeNodeItem> _treeNodeItems;
        private TabControl.TabPageCollection _tabPages;

        // Properties
        public ObservableList<TreeNodeItem> TreeNodeItems
        {
            get { return _treeNodeItems; }
            set
            {
                if (_treeNodeItems != value)
                {
                    _treeNodeItems = value;
                    _treeNodeItems.OnPropertyChanged += OnPropretyChanged;
                    OnPropretyChanged(null, null);
                }
            }
        }

        public TabControl.TabPageCollection TabPages
        {
            get
            {
                return this._tabPages;
            }
        }

        // Events
        private void OnPropretyChanged(object sender, PropertyChangedEventArgs e)
        {
            if (sender == null) // If list got set
            {
                // Remove existing tabpages
                this._tabPages.Clear();

                // Loop through all items inside the ObservableList object and add them to the Tabpage
                foreach (TreeNodeItem _treeNodeItem in this._treeNodeItems)
                {
                    TabPage tabPage = new TabPage() { Text = _treeNodeItem.Value, Tag = _treeNodeItems };
                    this._tabPages.Add(tabPage);
                }
            }
            else if (sender is object[]) // If only one (or multiple) objects have been changed
            {
                // Get OldItems and NewItems
                object[] changedItems = (object[])sender;
                // Remove OldItems
                if (changedItems[0] != null)
                {
                    foreach (dynamic oldItems in (IList)changedItems[0])
                    {
                        foreach (TabPage tab in this._tabPages)
                        {
                            if (tab.Text == oldItems.Value)
                            {
                                this._tabPages.Remove(tab);
                                break;
                            }
                        }

                    }
                }
                // Add OldItems
                if (changedItems[1] != null)
                {
                    foreach (dynamic newItems in (IList)changedItems[1])
                    {
                        TabPage tabPage = new TabPage() { Text = newItems.Value, Tag = newItems };
                        this._tabPages.Add(tabPage);
                    }
                }
            }
        }
    }

这是一个关于如何使用它的示例:

    TabControlBind tabControlBinder;
    ObservableList<TreeNodeItem> treeNodeItems;

    private void btnAdd_Click(object sender, EventArgs e)
    {
        // This will automatically update the TabControl
        treeNodeItems.Add(new TreeNodeItem(new NTree<string>() { data = "Test3" }));
    }

    private void frmMain_Load(object sender, EventArgs e)
    {
        // Create a new list object an add items to it
        treeNodeItems = new ObservableList<TreeNodeItem>();
        treeNodeItems.Add(new TreeNodeItem(new NTree<string>() { data = "Test" }));
        treeNodeItems.Add(new TreeNodeItem(new NTree<string>() { data = "Test2" }));

        // Create a new instance of the TabControlBind class, set it to our TabControl
        tabControlBinder = new TabControlBind(tabControl);
        tabControlBinder.TreeNodeItems = treeNodeItems;
    }