lookupedit按值设置选择

我有一个lookupedit，我需要通过单击按钮的事件来设置它的选择。但我做不到。

这就是我填充lookupedit 的方式

using (SqlConnection conn = new SqlConnection(GlobalParameters.logoSqlConnectionString))
        {
            conn.Open();
            string selectSql = @"SELECT LOGICALREF,DEFINITION_ FROM [LG__CLCARD]";
            DataTable dtDetail = GlobalParameters.getDataTable(selectSql, GlobalParameters.logoSqlConnectionString);
            lookUpEditGeldigiFirma.Properties.DataSource= dtDetail;
            lookUpEditGeldigiFirma.Properties.DisplayMember = "DEFINITION_";
            lookUpEditGeldigiFirma.Properties.NullText = "Lütfen seçiniz.";
            lookUpEditGeldigiFirma.Properties.ValueMember = "LOGICALREF";
        }

我的lookupedit有三个元素，如下所示。

value:1  text:apple
value:2  text:orange
value:3  text:melon

我试着将选择设置为如下

// first attempt
lookUpEditGeldigiFirma.EditValue = "2";
// second attempt
lookUpEditGeldigiFirma.Properties.DisplayMember = "orange";
// third attempt
lookUpEditGeldigiFirma.Properties.ValueMember = "2";

这些尝试都无法在lookupedit中设置所选内容。请帮助我

lookUpEditGeldigiFirma.EditValue = 2;