您可以使用SelectedItem属性并选择所需的项目

You can use the SelectedItem property and pick the item you want

使用您提供的结构，这是一个快速示例:

Using the struct you provided, here's a quick sample:

    private void button1_Click(object sender, EventArgs e)
    {
        cmbMarkers.DataSource = null;
        var markerList = new List<MarkerRecord>
        {
            new MarkerRecord(1, "first"), new MarkerRecord(2, "second")
        };
        cmbMarkers.ValueMember = "MarkerId";
        cmbMarkers.DisplayMember = "MarkerName";
        cmbMarkers.DataSource = markerList;
        cmbMarkers.SelectedItem = markerList.FirstOrDefault(mr => mr.MarkerId == 2); //second item selected
    }

在最后一行，您可以选择要选择的项目.

On the last line, you get to choose which item you want selected.