Question

我有包含项目集合的列表框。从列表框中删除项目后，我想从列表框中删除该项目而不重新加载整个集合，这是否可以在winforms中进行？

 private void btnDelete_Click(object sender, EventArgs e)
        {
            MyData sel = (MyData)listBox1.SelectedItem;
            if (...delete data)
            {
                listBox1.Items.Remove(listBox1.SelectedItem);
                MessageBox.Show("succ. deleted!");
            }
            else
            {
                MessageBox.Show("error!");
            }           
        }

我收到错误

数据源属性时，无法修改项集合设置

Answer 1

嘿尝试从您的收藏集中获取所选项目索引，然后按索引删除项目表单集合，然后再次将列表框绑定到集合..

我已经提供了示例代码，请参阅。

public partial class Form1 : Form
{
    List<String> lstProduct = new List<String>();
    public Form1()
    {

        InitializeComponent();
    }

    public List<String> BindList()
    {

        lstProduct.Add("Name");
        lstProduct.Add("Name1");
        lstProduct.Add("Name2");
        lstProduct.Add("Nam3");
        lstProduct.Add("Name4");

        return lstProduct;
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        listBox1.DataSource = BindList();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        // The Remove button was clicked.
        int selectedIndex = listBox1.SelectedIndex;

        try
        {
            // Remove the item in the List.
            lstProduct.RemoveAt(selectedIndex);
        }
        catch
        {
        }

        listBox1.DataSource = null;
        listBox1.DataSource = lstProduct;
    }
}

希望它可以帮助你......

Answer 2

您应该将可观察集合用作DataSource。您可以使用内置版本，例如BindingList<T>和ObservableCollection<T>。

但您也可以考虑创建自己的集合并实施IBindingList或INotifyCollectionChanged界面。

<强>更新

public partial class YourForm : Form
{
    private BindingList<string> m_bindingList = new BindingList<string>();

    private YourForm()
    {
        InitializeComponent();
        yourListBox.DataSource = m_bindingList;

        // Now you can add/remove items to/from m_bindingList
        // and these changes will be reflected in yourListBox.

        // But you shouldn't (and can't) modify yourListBox.Items
        // as long as DataSource is set.
    }

    private void btnDelete_Click(object sender, EventArgs e)
    {
        // Removing items by indices is preferable because this avoids
        // having to lookup the item by its value.
        m_bindingList.RemoveAt(yourListBox.SelectedIndex);
    }
}

从列表框项目列表中删除删除项目

2 个答案: