为什么我没有在组合框中获得实际选择的值？

Question

我有两个组合框 cmbfrom 和 cmbdest..

从 SQL 数据库中检索数据并将其设置为组合框值的代码如下：

databaseserver ser = new databaseserver();
SqlConnection con = new SqlConnection(ser.dbserver + "Initial Catalog=AirlinesDB;Integrated Security=True");
con.Open(); 
SqlDataAdapter citiesadp = new SqlDataAdapter("select city from cities",con);
DataSet dset = new DataSet(); //Creating instance of DataSet
citiesadp.Fill(dset,"cities");
cmbfrom.DataSource = dset.Tables["cities"];
cmbfrom.DisplayMember = "city";
con.Close();

SqlConnection con1 = new SqlConnection(ser.dbserver + "Initial Catalog=AirlinesDB;Integrated Security=True");
con1.Open();
SqlDataAdapter destcity = new SqlDataAdapter("select city from cities",con1);
DataSet destset = new DataSet();
destcity.Fill(destset,"cities");
cmbdest.DataSource = destset.Tables["cities"];
cmbdest.DisplayMember = "city";
con1.Close();

但是当我在cmbdest 中选择一个值时，它返回给我System.Data.DataRowView，而不是实际值。

从组合框中检索选定值的代码如下：

textBox1.Text = cmbdest.SelectedValue.ToString();
textBox2.Text = cmbfrom.SelectedValue.ToString();

我从第一个组合（即所选城市名称）获得实际值，但第二个组合获得值：System.Data.DataRowView。

Answer 1

您应该首先为cmbfrom 设置属性ValueMember

Answer 2

请尝试以下代码：

    databaseserver ser = new databaseserver();
    SqlConnection con = new SqlConnection(ser.dbserver + "Initial Catalog=AirlinesDB;Integrated Security=True");
    con.Open(); 
    SqlDataAdapter citiesadp = new SqlDataAdapter("select city from cities",con);
    DataSet dset = new DataSet(); //Creating instance of DataSet
    citiesadp.Fill(dset,"cities");
    cmbfrom.DataSource = dset.Tables["cities"];
    cmbfrom.DisplayMember = "city";
    cmbfrom..ValueMember= "city";

    con.Close();

    SqlConnection con1 = new SqlConnection(ser.dbserver + "Initial Catalog=AirlinesDB;Integrated Security=True");
    con1.Open();
    SqlDataAdapter destcity = new SqlDataAdapter("select city from cities",con1);
    DataSet destset = new DataSet();
    destcity.Fill(destset,"cities");
    cmbdest.DataSource = destset.Tables["cities"];
    cmbdest.DisplayMember = "city";
    cmbdest..ValueMember= "city";
    con1.Close();