I hope this piece of code will help you get started:
FeatureLayer featureLayer = (FeatureLayer)mobileCache1.Layers["Streets"];
DataTable dt = (DataTable)featureLayer.GetDomain(0,"street_name");
comboBox1.ValueMember = "Code"; //** Column name is case sensitive
comboBox1.DisplayMember = "Value";
comboBox1.DataSource = dt;