C# Winforms ListBox 项目满足条件时设置背景色

Question

我有一个集合，它是列表框的数据源。我想枚举 ListBox 项并在集合项具有特定属性时更改 BackColor。 for 中的代码根本不起作用，我迷路了。如果相应的类别具有特定 ID，我将如何更改背景颜色？

  categorien.Add(new Categorie() { ID = 0, Naam = "Blond" });
  categorien.Add(new Categorie() { ID = 1, Naam = "Donker" });
  listBox1.DataSource = categorien;
  listBox1.DisplayMember = "Naam";
  listBox1.ValueMember = "ID";

  for (int i = 0; i < listBox1.Items.Count; i++ ) {
    if (categorien.ID == someID) {
      listBox1.Items[i].BackColor = Color.Gray;
    }
  }

Answer 1

试试下面

private void listBox1_DrawItem(object sender, DrawItemEventArgs e)
{
    var category = listBox1.Items[e.Index] as Categorie;
    Color backColor = Color.Green;
    if (category.ID == someID)
    {
        backColor = Color.Gray;
    }

    // draw back color and text 
}