c# - CopyListBoxItem 从一个 ListBox 到另一个

Question

我有两个列表框。我想将 SelectedItem 从第一个 ListBox 复制到第二个。

为什么这段代码不起作用？

    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);            
        }
    }

我得到的结果:

Answer 1

试试这个 我不确定你为什么要寻找一个 Contains 但如果你真的需要看看 SelectedValue 和 SelectedItem

之间的区别

Use this code right here as a test to see if the expected value shows up in a MessageBox

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

这应该可以帮助您查看右侧列表框中的值

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);
    }
}