如何在弹出窗口中禁用组合框中的项目

Question

Is there any way to disable specific item inside combobox based on condition. which need to display on click of combobox ie on popup show

Answer 1

Step 1. Set the property DrawMode of the ComboBox to OwnerDrawFixed

Step 2. Change the Item color using Index value

 Font fontValue = new Font("calibri", 12, FontStyle.Regular);

 //Form Load
 private void form_Load(object sender, EventArgs e)
 {
    List<string> lstCombxValue = new List<string>();
    lstCombxValue.Add("Item A1");
    //Item to Disable
    lstCombxValue.Add("Item A2");
    lstCombxValue.Add("Item A3");
    lstCombxValue.Add("Item A4");
    lstCombxValue.Add("Item A5");
    lstCombxValue.Add("Item A6");

    comboBox1.DataSource = lstCombxValue;
 }

 private void comboBox1_DrawItem(object sender, DrawItemEventArgs e)
 {
     //Check the Condition get the Item Index Value to Disable 
     //and follow this step to disable the item
     if (e.Index == 1)
     {
         e.Graphics.DrawString(comboBox1.Items[e.Index].ToString(), fontValue, Brushes.Gray, e.Bounds);
     }
     else
     {
         e.DrawBackground();
         e.Graphics.DrawString(comboBox1.Items[e.Index].ToString(), fontValue, Brushes.Black, e.Bounds);
         e.DrawFocusRectangle();
     }
 }