将文本框绑定到comboBox.SelectedItem 的属性

我正在使用 winforms，并且有一个代表 IQueryable 的组合框。组合框下方是一系列文本框，我希望将它们绑定到组合框中当前选择的文本框。

这是我的代码。

public partial class TestForm : Form
{
    public DataClassesDataContext DataContext;

    public IQueryable<T> datasource;

    // Ctor
    public TestForm()
    {
    InitializeComponent();

    // L2S data context
    this.DataContext = new DataClassesDataContext();

    // Get the variable for the data source
    this.datasource = this.DataContext.Ts;

    // setup the binding for the combobox
    this.comboBox1.DataSource = this.datasource;
    this.comboBox1.DisplayMember = "Description";
    this.comboBox1.ValueMember = "Id";

    // assign the databindings of the text boxes to the selectedItem of the combo box    
    // this is where the problem is, afaik
    TId.DataBindings.Add(new Binding("Text", this.comboBox1.SelectedItem, "Id"));
    TUser.DataBindings.Add(new Binding("Text", this.comboBox1.SelectedItem, "User"));
    TDescription.DataBindings.Add(new Binding("Text", this.comboBox1.SelectedItem, "Description"));
}

这样做会绑定所有内容，当我更改文本框中的值时，它会很好地更新组合框中最初选定的项目。即使当我更改描述时，它也会更新 drop don 中显示的文本，这一切都很棒。

但是，当我从下拉列表中选择不同的项目时，文本框不会绑定到新选择的项目，而是保持绑定到旧的项目。

每次组合框中的选择发生变化时，我是否需要删除并重新添加绑定？

我原来的答案是错误的，诚然，我并不完全理解这里发生的一切，但我有一个有效的解决方案。

基本上你需要抓住BindingManagerBase来自BindingContext并使用它来强制每个SelectedItemChanged event.

public partial class TestForm : Form
{
    public DataClassesDataContext DataContext;

    public IQueryable<T> datasource;
    private BindingManagerBase bmComboBoxSelectedItem;

    // Ctor
    public TestForm()
    {
        InitializeComponent();

        // L2S data context
        this.DataContext = new DataClassesDataContext();

        // Get the variable for the data source
        this.datasource = this.DataContext.Ts;

        // setup the binding for the combobox
        this.comboBox1.DataSource = this.datasource;
        this.comboBox1.DisplayMember = "Description";
        this.comboBox1.ValueMember = "Id";

        // assign the databindings of the text boxes to the selectedItem of the combo box    
        // this is where the problem is, afaik
        TId.DataBindings.Add(new Binding("Text", this.comboBox1, "SelectedItem.Id"));
        TUser.DataBindings.Add(new Binding("Text", this.comboBox1, "SelectedItem.User"));
        TDescription.DataBindings.Add(new Binding("Text", this.comboBox1, "SelectedItem.Description"));

        bmComboBoxSelectedItem = this.BindingContext[this.comboBox1, "SelectedItem"];
    }

    // make sure you assign this event on the forms designer or your preferred method
    private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
    {
        bmCustomers.ResumeBinding();
    }
}

This MSDN 文章 http://msdn.microsoft.com/en-us/library/system.windows.forms.binding.aspx帮了很多忙。