如何绑定到 CheckedListBox.SelectedItems.Count

Question

I am trying to bind a label to a CheckedListBox.CheckedItems.Count I have tried a couple approaches to this and receive the message:

Cannot bind to the property or column Count on the DataSource. Parameter name: dataMember

My Code is as Follows:

    Dim BgCountBinding As Binding = New Binding("Text", BgCheckedListBox.CheckedItems, "Count")

  ' I have also tried this:     
  ' Dim BgCountBinding As Binding = New Binding("Text", BgCheckedListBox, "CheckedItems.Count")

    BgCountBinding.DataSourceUpdateMode = DataSourceUpdateMode.Never
    BgCountBinding.ControlUpdateMode = ControlUpdateMode.OnPropertyChanged
    BgCountBinding.NullValue = "0"
    BgCountBinding.FormattingEnabled = True
    BgCountBinding.FormatString = "#: {0}"


    lblBGCount.DataBindings.Add(BgCountBinding)

I know the code is VB but if you have a C# version - I can and will be happy to convert it.

Answer 1

Since the CheckListBox doesn't support multi-selection, probably you mean CheckItems.Count . You can not bind to CheckItems.Count . To be notified about changing in CheckedItem.Count you should handle ItemCheck event of the CheckedListBox :

C#

this.checkedListBox1.ItemCheck += (s, ea) =>
{
    this.BeginInvoke(new Action(() =>
    {
        this.label1.Text = this.checkedListBox1.CheckedItems.Count.ToString();
    }));
};