c# - 从 AutoCompleteStringCollection c# 中删除重复项

Question

AutoCompleteStringCollection treatmentCollection = new AutoCompleteStringCollection();
if (con.State == ConnectionState.Closed)
{
    con.Open();
}
SqlCeCommand cmdTreatment = new SqlCeCommand("select Treatment from NewPatient", con);
SqlCeDataReader readerTreatment = cmdTreatment.ExecuteReader();
if (readerTreatment.Read() == true)
{
    while (readerTreatment.Read())
    {
        treatmentCollection.Add(readerTreatment["Treatment"].ToString());
    }
}
comboBox2.AutoCompleteMode = AutoCompleteMode.Suggest;
comboBox2.AutoCompleteSource = AutoCompleteSource.CustomSource;
comboBox2.AutoCompleteCustomSource = treatmentCollection;
if (con.State == ConnectionState.Open)
{
    con.Close();
}

我希望 combobox2 应该只有不同的值。组合框从 AutoCompleteStringCollection 类的 treatmentCollection 对象获取值请帮帮我？

Answer 1

替换:

select Treatment from NewPatient

为此:

select distinct Treatment from NewPatient