從一個ListBox復制到另一個ListListBoxItem

Question

我有兩個列表框。 我想將SelectedItem從第一個ListBox復制到第二個。

為什么此代碼不起作用？

    private void frm_addDispatchBoard2_Load(object sender, EventArgs e)
    {
        using(propertiesManagementDataContext db = new propertiesManagementDataContext())
        {
            var Buildings = db.Buildings.Select(q => new { q.BuildingLandNumber, q.BuildingId });

            listBox_allBuildings.DataSource = Buildings;
            listBox_allBuildings.DisplayMember = "BuildingLandNumber";
            listBox_allBuildings.ValueMember = "BuildingId";
        }          
    }

    private void btn_addBuilding_Click(object sender, EventArgs e)
    {
        if(listBox_allBuildings.SelectedIndex > 0)
        {
            listBox_selectedBuildings.Items.Add(listBox_allBuildings.SelectedItem);            
        }
    }

我得到的結果是：

Answer 1

試試這個我不確定為什么您要尋找一個包含對象，但是如果您真的需要，請查看SelectedValue和SelectedItem之間的區別

在此處使用此代碼作為測試，以查看期望值是否顯示在MessageBox中

string selected = listBox_allBuildings.GetItemText(listBox_allBuildings.SelectedValue);    
MessageBox.Show(selected);

這應該可以幫助您查看右側列表框中的值

private void btn_addBuilding_Click(object sender, EventArgs e)
{
    if(listBox_allBuildings.SelectedIndex != -1)
    {
       var selected = listBox_allBuildings.GetItemText(listBox_allBuildings.SelectedValue);     
       listBox_selectedBuildings.Items.Add(selected);
    }
}