c# – ListBox.DataSource集合与ListBox.Items之间的区别？

我正在动态创建 Winforms多选ListBox并将其添加到flowpanel控件中.我从我创建的对象绑定数据源,并验证DataSource实际上有大约14个元素.当我执行listBox.SetSelected(0,true)时,我收到一个System.ArgumentOutOfRangeException错误.

我已经确定问题是,虽然DataSource有14个元素,但Item集合没有(0),因此抛出异常.我的问题是为什么这两者彼此不同,为什么我不简单地在数据源中添加一个foreach项添加到项集合中？

以下是我到目前为止的代码：

case InsertableItemParameter.ParameterType.ListBox:
    //note: two-way bindings are not possible with multiple-select listboxes
    Label lblListBox = new Label();
    lblListBox.Text = param.DisplayText;
    ListBox listBox = new ListBox();
    listBox.DataSource = param.Values;
    listBox.DisplayMember = "Value";
    listBox.SelectionMode = SelectionMode.MultiExtended;
    listBox.Size = new System.Drawing.Size(flowPanel.Size.Width - lblListBox.Size.Width - 10,100);
    listBox.SetSelected(0,true);   //will throw argument out of range exception here!
    listBox.SetSelected(1,true);
    flowPanel.Controls.Add(lblListBox);
    flowPanel.Controls.Add(listBox);
    flowPanel.SetFlowBreak(listBox,true);
    break;

下面是我尝试和工作的替代解决方案,但为什么我会使用DataSource与Items集合？

case InsertableItemParameter.ParameterType.ListBox:
    //note: two-way bindings are not possible with multiple-select listboxes
    Label lblListBox = new Label();
    lblListBox.Text = param.DisplayText;
    ListBox listBox = new ListBox();
    //listBox.DataSource = param.Values;
    listBox.DisplayMember = "Value";
    listBox.SelectionMode = SelectionMode.MultiExtended;
    listBox.Size = new System.Drawing.Size(flowPanel.Size.Width - lblListBox.Size.Width - 10,100);
    listBox.BeginUpdate();
    foreach (String paramater in param.Values)
    {
        listBox.Items.Add(paramater);
    }
    listBox.EndUpdate();
    listBox.SetSelected(0,true);
    listBox.SetSelected(1,true);
    break;

答案：感谢所有回复.这里的问题是可见性和win-form呈现.虽然除了少数人之外没有真正解决DataSource和Items集合之间的差异,但是在完成绘制表单之后调用SetSelected()方法解决了我的问题的真正来源.这导致我的应用程序设计中的许多问题,我必须解决,但这是问题所在.请参阅我标记为答案的回复.

string[] ds = {"123","321"};
listBox1.DataSource = ds;
listBox1.SetSelected(1,true);
MessageBox.Show(listBox1.Items.Count.ToString()); //returns 2

string[] ds = { "123","321" };
ListBox lst = new ListBox();
lst.DataSource = ds;
lst.Size = new Size(100,100);            
this.Controls.Add(lst);
//make sure to call SetSelected after adding the ListBox to the parent
lst.SetSelected(1,true);

listBox.SetSelected(0,true);
listBox.SetSelected(1,true);
flowPanel.Controls.Add(lblListBox);
flowPanel.Controls.Add(listBox);

flowPanel.Controls.Add(lblListBox);
flowPanel.Controls.Add(listBox);
listBox.SetSelected(0,true);